The floral biology and pollination of Clusia arrudae was studied at "Serra da Calcada". C. arrudae does not present apomixis even when resin is deposited on the stigma. Fruits developed from flowers manually pollinated produced more seeds (6.3 per locule in average) than fruits developed from flowers naturally pollinated (4.3 seeds per locule). Blooming of C. arrudae peaks between December and mid-February. Male and female individuals of C. arrudae produce flowers daily; however, each three days there is a synchronized anthesis peak within the population. Sexual rate in the population is 1:1, with male plants producing more flowers than female. Male flowers produce about 11X106 pollen grains along the three day anthesis. Most of them (about 66%) are presented on the first day. The stigmas of female flowers remain receptive for three days or four days when pollination does not happen in the first three days. Flowers of C. arrudae were visited by six species of bees for pollen or resin collection. Workers of Apis mellifera and Trigona spinipes, and females of Xylocopa frontalis and Neocorynura sp. visited male flowers for pollen; workers of Trigona spinipes also visited female flower for resin collection. Workers of Melipona quadrifasciata and females of Eufriesea nigrohirta were observed collecting resin on both male and female flowers. Due to its frequency and behavior on flowers of both sexes, E. nigrohirta is the main pollinator of C. arrudae at "Serra da Calcada".

A survey on the phenology and reproductive biology of Copaifera langsdorffii Desf. was carried out in a cerradao area at Fazenda Capim Branco, Uberlandia, MG. Flowering occurs during the rain season and seed dispersal during the dry season. Flowers are pale-green, 0.5 cm in diameter, weakly zigomorphic and organized in particulate inflorescences. They are highly odoriferous, one-day flowers. Anthesis begins at about 5:00 h. The nectar production is very small (0.2 mul) with 49% of sucrose equivalents. The most frequent flower visitors and pollinators were Apis mellifera, Scaptotrigona cf. depiles and Trigona spinipes bees. Controlled hand-pollinations showed that the species is mostly self-sterile and non -apomictic. However, pollen tubes were observed growing down to the ovary and penetrating the ovules in self-pollinated pistils, a fact which suggests late-acting self-sterility phenomena or inbreeding depression. Fruit-set was always low and related to low flower to fruit conversion, may be due to inefficient pollination and fruit predation.

Multiple mating by social insect queens increases the genetic diversity among colony members, thereby reducing intracolony relatedness and lowering the potential inclusive fitness gains of altruistic workers. Increased genetic diversity may be adaptive, however, by reducing the prevalence of disease within a nest. Honeybees, whose queens have the highest levels of multiple mating among social insects, were investigated to determine whether genetic variation helps to prevent chronic infections. I instrumentally inseminated honeybee queens with semen that was either genetically similar (from one male) or genetically diverse (from multiple males), and then inoculated their colonies with spores of Ascosphaera apis, a fungal pathogen that kills developing brood. I show that genetically diverse colonies had a lower variance in disease prevalence than genetically similar colonies, which suggests that genetic diversity may benefit colonies by preventing severe infections.

Systematical observations and researches were conducted on the population size dynamics of Apis mellifera Ligustica Spi. and Apis cerana cerana Feb. in Wanzhong, Wanxi and Wannan mountainous area in Anhui Province in 1997 -1999. The results showed that the bee population size was influenced by climate and flower fertility, which was higher in Spring and Autumn, and lower in Summer and Winter. The propagation and renewal of A. mellifera in Autumn were quicker than those of A. cerana cerana, while the effect of overcoming Summer was inferior to that of Apis cerana cerana. The sex ratio of A. mellifera was (314.4 +- 289.9): 1-(329.4 +- 305.8): 1, and that of A. cerana cerana was (334.2 +- 235.5): 1-(413.1 +- 377.2): 1. The birth of drones was seasonal, and the age structure of each bee population was variable.

Reproduction and population growth of Varroa destructor was studied in ten naturally infested, Africanized honey bee (AHB) (Apis mellifera) colonies in Yucatan, Mexico. Between February 1997 and January 1998 monthly records of the amount of pollen, honey, sealed worker and drone brood were recorded. In addition, mite infestation levels of adult bees and worker brood and the fecundity of the mites reproducing in worker cells were determined. The mean number of sealed worker brood cells (10,070+-1,790) remained fairly constant over the experimental period in each colony. However, the presence and amount of sealed drone brood was very variable. One colony had drone brood for 10 months and another for only 1 month. Both the mean infestation level of worker brood (18.1+-8.4%) and adult bees (3.5+-1.3%) remained fairly constant over the study period and did not increase rapidly as is normally observed in European honey bees. In fact, the estimated mean number of mites fell from 3,500 in February 1997 to 2,380 in January 1998. In May 2000 the mean mite population in the study colonies was still only 1,821 mites. The fertility level of mites in this study was much higher (83-96%) than in AHB in Brazil (25-57%), and similar to that found in EHB (76-94%). Mite fertility remained high throughout the entire study and was not influenced by the amount of pollen, honey or worker brood in the colonies.

Mites in the genus Varroa are the primary parasites of honey bees on several continents. Genetic analyses based on Varroa mitochondrial DNA have played a central role in establishing Varroa taxonomy and dispersal. Here we present the complete mitochondrial sequence of the important honey bee pest Varroa destructor. This species has a relatively compact mitochondrial genome (15,218 bp). The order of genes encoding proteins is identical to that of most arthropods. Ten of 22 transfer RNAs are in different locations relative to hard ticks, and the 12S ribosomal RNA subunit is inverted and separated from the 16S rRNA by a novel non-coding region, a trait not yet seen in other arthropods. We describe a dispersed set of 45 oligonucleotide primers that can be used to address genetic questions in Varroa. A subset of these primers should be useful for taxonomic and phylogenetic studies in other mites and ticks.

It has been difficult to manipulate the ultraviolet (UV) reflectance of flowers independently of other wavelengths to study the response of insect pollinators to this trait. One effective solution is to paint flower corollas with human sunscreen that absorbs UV wavelengths. Honeybees (Apis mellifera scutellata) foraging on the strongly UV-reflecting flowers of Hypoxis hemerocallidea Fisch. AMPERSAND C.A. Mey. rejected flowers that had UV reflectance eliminated by a sunscreen coating, but continued to visit control flowers painted with sunscreen solution that did not contain the UV absorbing compound. The sunscreen technique could be useful for determining the response of a wide range of pollinators to the UV component of spectral reflectance in flowers and could be used to test the functional significance of UV-contrasting "nectar guide" patterns.

Human envenomation caused by bee stings has been reported to cause acute renal failure and the pathogenetic mechanisms of these renal functional changes are still unclear. Bee venom is also a complex mixture of enzymes and proteins. Thus, this study was conducted to examine the effects of bee venom (BV, Apis mellifera) fractions on apical transporters' activity and its related signal pathways in primary cultured renal proximal tubule cells. Whole BV was extracted into three fractions according to solubility (a water-soluble fraction (BVA), an ethylacetate-soluble fraction (BVE), and a hexane-soluble fraction (BVH)). BVA fraction was further separated to three portions according to molecular weights: BF1 ( RGT 20 kD), BF2 (10-20 kD), and BF3 ( LGT 10 kD). Each fraction was treated to the PTCs to the ratio of BV (1 mug/ml). BVA (930 ng/ml) significantly decreased cell viability, but BVH (27 ng/ml) and BVE (43 ng/ml) did not. BF3 (710 ng/ml) among BVA fractions predominantly decreased cell viability and inhibited alpha -methyl-D-glucopyranoside (alpha-MG), phosphate (Pi), and Na+ uptake. In addition, BF3 increased (3H) arachidonic acid release, lipid peroxide formation, and Ca2+ uptake. These effects of BF3 were blocked by mepacrine and AACOCF3 (phospholipase A2 inhibitors) or N-acetylcysteine, vitamin C, and vitamin E (antioxidants). In conclusion, BF3 ( LGT 10 kD) among BV fractions is the most effective portion in BV-induced inhibition of alpha -MG, Pi, and Na+ uptake and these effects of BF3 are associated with phospholipase A2-oxidative stress-Ca2+ signal cascade in the primary cultured rabbit renal proximal tubule cells.

Vitellogenin is a female-specific glucolipoprotein yolk precursor produced by all oviparous animals. Vitellogenin expression is under hormonal control, and the protein is generally synthesized directly before yolk deposition. In the honeybee (Apis mellifera), vitellogenin is not only synthesized by the reproductive queen, but also by the functionally sterile workers. In summer, the worker population consists of a hive bee group performing a multitude of tasks including nursing inside the nest, and a forager group specialized in collecting nectar, pollen, water, and propolis. Vitellogenin is synthesized in large quantities by hive bees. When hive bees develop into foragers, their juvenile hormone titers increase, and this causes cessation of their vitellogenin production. This inverse relationship between vitellogenin synthesis and juvenile hormone is opposite to the norm in insects, and the underlying proximate processes and life-history reasons are still not understood. Here we document an alternative use of vitellogenin by showing that it is a source for the proteinaceous royal jelly that is produced by the hive bees. Hive bees use the jelly to feed larvae, queen, workers, and drones. This finding suggests that the evolution of a brood-rearing worker class and a specialized forager class in an advanced eusocial insect society has been directed by an alternative utilization of yolk protein.

The present study aimed to determine the foraging activity, load carrying capacity and foraging trip frequency of Apis mellifera during 1995-98 showed similar diurnal pattern in respect of number of pollen foragers, pollen load size and number of pollen foraging trips on one hand and number of nectar foragers, nectar load size and nectar foraging trips on the other hand. However, minimum foraging index was observed on mid day. Comparatively, the foraging performance of A. mellifera was better during 1997-98 than previous years 1995-97 of the study period.

Published documentation of insect pests and pathogens associated with Alnus species in Africa is very scarce. We surveyed damaging insects and pathogens, and arthropod natural enemies on Alnus acuminata and A. nepalensis in Kabale and Mbale districts, Uganda between March 1999 and August 2000 in order to identify the range and relative abundance of arthropods and pathogens associated with the Alnus species. Frequently encountered damaging insects on the Alnus species included Apis mellifera, Apion globulipenne, a Systates sp. (Coleoptera: Curculionidae), Phymateus viridipes, a Lobotrachelus sp. (Coleoptera: Curculionidae), Coloborrtics corticina and some Chrysomelidae. Some species such as Aphis fabae, Parastictococcus multispinosus and a Cacopsylla sp. (Homoptera: Psyllidae) were observed feeding on other agroforestry tree species and/or crops although they generally occurred at low population intensities. Spiders and parasitic Hymenoptera were the most common natural enemies. Diseases were more severe in nurseries than in the field. Damping-off caused by Fusarium oxysporum, Septoria brown leaf spot and stem canker were the most serious diseases of Alnus. The array of damaging insects and pathogens indicates a potential danger to the cultivation of Alnus species in Uganda as adoption of the species for agroforestry continues to expand in the country. In view of the increasing demand for Alnus species for agroforestry in Uganda, regular pest monitoring and appropriate control strategies are necessary.

Efficient division of labor is one of the main reasons for the success of the social insects. In honey bees the division of labor is principally achieved by workers changing tasks as they age. Typically, young adult bees perform a series of tasks within the colony before ultimately making the transition to foraging outside the hive for resources. This lifelong behavioral development is a well-characterized example of naturally occurring behavioral plasticity, but its neural bases are not well understood. Two techniques were used to assess the role of biogenic amines in the transition from in-hive work to foraging, which is the most dramatic and obvious transition in honey bee behavioral development. First, associations between amines and tasks were determined by measuring the levels of amines in dissected regions of individual bee brains using HPLC analysis. Second, colonies were orally treated with biogenic amines and effects on the onset of foraging were observed. Octopamine concentration in the antennal lobes of the bee brain was most reliably associated with task: high in foragers and low in nurses regardless of age. In contrast, octopamine in the mushroom bodies, a neighboring neuropil, was associated with age and not behavior, indicating independent modulation of octopamine in these two brain regions. Treating colonies with octopamine resulted in an earlier onset of foraging in young bees. In addition, octopamine levels were not elevated by non-foraging flight, but were already high on return from the first successful foraging trip and subsequently remained high, showing no further change with foraging experience. This observation suggests that octopamine becomes elevated in the antennal lobes in anticipation of foraging and is involved in the release and maintenance of the foraging state. Foraging itself, however, does not modulate octopamine levels. Behaviorally related changes in octopamine are modulated by juvenile hormone, which has also been implicated in the control of honey bee division of labor. Treatment with the juvenile hormone analog methoprene elevated octopamine and octopamine treatment 'rescued' the delay in behavioral development caused by experimentally depleting juvenile hormone in bees. Although the pathways linking juvenile hormone and octopamine are presently unknown, it is clear that octopamine acts 'downstream' of juvenile hormone to influence behavior and that juvenile hormone modulates brain octopamine levels. A working hypothesis is that octopamine acts as an activator of foraging by modulating responsiveness to foraging-related stimuli. This is supported by the finding that octopamine treatment increased the response of bees to brood pheromone, a stimulator of foraging activity. Establishing a role for octopamine in honey bee behavioral development is a first step in understanding the neural bases of this example of naturally occurring, socially mediated, behavioral plasticity. The next level of analysis will be to determine precisely where and how octopamine acts in the nervous system to coordinate this complex social behavior.

A role of the Honeybee (Apis mellifera) as a prey of the Blue-cheeked Bee -eater (Merops persicus Pall.) was studied in the lower reaches of the Zeravshan River (southern Kizilkum, Uzbekistan) in 1989-1991. The honeybees were recorded in food of the Blue-cheeked Bee-eater in 10 of 13 localities studied ranging from 0.5% to 54.7% of the total numberot prey items. There was also a large geographical and seasonal variation in the consumption rate of honeybees by Blue-cheeked Bee-eater. A strong relationship was fond between the percentage of honeybees in the diet of nestlings and distance from apiary.

Multivariate discriminant analyses of nine standard morphometric characters of honeybee workers were used to track the origin of a social parasitic pseudo-clone of thelytokous laying workers that have invaded colonies of Apis mellifera scutellata in South Africa. Twenty social parasitic workers were sampled from both of two infested A. m. scutellata colonies at two distant apiaries (Graskop and Heilbronn, about 390 km apart) and compared with data obtained from 80 colonies in four different geographical zones (zone I: thelytokous A. m. capensis morphocluster; zone II: natural thelytokous hybrids between A. m. capensis and A. m. scutellata; zone III: thelytokous A. m. scutellata morphocluster; zone IV: an arrhenotokous A. m. scutellata morphocluster). Thelytokous laying workers occur naturally in zones I-III. Highly significant morphometric differences were found among the bees in the four zones. The data support the conclusion that the social parasitic workers belong to the thelytokous A. m. capensis morphocluster. It is most likely that the social parasitic workers originated from the heart of the Cape bee's distribution range in the Western Cape region in zone I. Morphometric analysis makes it feasible to restrict the possible origin of the social parasitic workers from the natural distribution range of thelytoky (approximately 240 000 km2) down to about 12 000 km2, which represents a resolution capacity of about 95%.

For this study, we constructed methods to detect the number of Paenibacillus larvae larvae spores in honey, and found that the detection limit was 181 spores/g of honey. Honey samples were examined using this method, and we found detectable levels of P. l. larvae in 31 of 124 samples from Taiwan. This method was also used to investigate the control effects of oxytetracycline (OTC) on American foulbrood (AFB). The results showed that in bee colonies with a heavy AFB infection (AFB signs RGT 500), the larval mortality might reach 62%, and the spore density might reach 1.2X106 spores/g of honey. All combs of these infected colonies were replaced with healthy ones and divided into three groups: one group was just fed syrup; one was medicated with 125 mg OTC; and the other one was given 50 mg OTC syrup. Their AFB signs, larval mortality, and spore density in honey were counted weekly. The results showed that 125 mg of OTC syrup eventually prevented AFB recurrence; i.e. no detectable levels of AFB signs or spores and normal larval mortality were found in the investigating period. However, good AFB prevention could not be achieved with treatment using syrup only or with 50 mg OTC medication. The larval mortality of these groups decreased with treatments but then increased again, and detectable spores and AFB signs were found in most samples in 3 -6 weeks post-treatment.

Although the caste concept has been central to our understanding of the organization of work in social insect colonies, the concept has been the subject of considerable recent criticism. Theoretically, it has been suggested that temporal castes are too inflexible to allow a colony to rapidly reallocate labour in response to changing conditions. In addition, several authors have suggested that task switching is so prevalent that it precludes even the possibility of a rigidly controlled temporal caste system. This study addresses these two criticisms by presenting and testing a revision of the temporal caste concept that recognizes two categories of tasks: those that require a physiological specialization for their efficient performance, and those that all workers are equally able to perform. Only those tasks requiring a physiological specialization are relevant to the temporal caste concept. Two castes of honeybees were shown to vary in response to increased nectar influx, which requires a physiological specialization, but not to heat stress, which requires no specialization. This work suggests that the organization of work in social insect colonies reflects a compromise between selection for the benefits of division of labour and opposing selection for flexibility in task allocation.

The mitochondrial DNA of Apis mellifera iberica, sampled in 72 beehives and 20 localities of Galicia (Northwest Spain) have been studied. A fragment of the subunit I of the cytochrome oxidase gene and the intergenic region between the tRNAleu and the subunit II of the cytochrome oxidase gene was amplified by PCR and digested with the endonucleases HincII and Dral respectively. Ninety-five percent of beehives from Lugo and La Coruna (the two Northern provinces) corresponds to the western European lineage (M), whereas in Orense and Pontevedra (the two Southern provinces) the haplotypes belonging to the African lineage (A) are more frequent. This pattern of haplotype distribution was previously known for other parts of the Iberian Peninsula, although in Galicia it shows the steepest transition. The presence of seven A haplotypes in Galicia suggests the occurrence of more than one colonising episode from the South. Further investigations are needed for assessing the influence of beekeeping, together with natural processes, in the genetic composition of bee populations of Galicia.

The efficacy of formic acid in a gel matrix was evaluated in two groups of honeybee colonies. In Group 1, a dispenser with 120 g of formic acid (70%) in gel was placed on the brood combs and another dispenser with the same dose was located on the hive bottom (total dose, 240 g). Group 2 received two doses of 240 g of formic acid (70%) in gel and each application was applied in two dispensers containing 120 g of the formic acid solution each and they were located over the brood chamber (total dose, 480 g). In Group 2, the period between both applications was 15 days, and the efficacies after the first and both applications were calculated. Significant differences were registered for final efficacy between both groups. When final efficacy of Group 1 was compared with efficacy after first application of Group 2, significant differences were found (P=0.0005). Same doses in different positions within the hive have different final efficacy. The higher efficacy was registered when the dispensers were placed over brood combs and on the hive bottom. It is suggested that efficacy is related to dispenser position within the hive.

Background: The ability to manipulate the genetic networks underlying the physiological and behavioural repertoires of the adult honeybee worker (Apis mellifera) is likely to deepen our understanding of issues such as learning and memory generation, ageing, and the regulatory anatomy of social systems in proximate as well as evolutionary terms. Here we assess two methods for probing gene function by RNA interference (RNAi) in adult honeybees. Results: The vitellogenin gene was chosen as target because its expression is unlikely to have a phenotypic effect until the adult stage in bees. This allowed us to introduce dsRNA in preblastoderm eggs without affecting gene function during development. Of workers reared from eggs injected with dsRNA derived from a 504 bp stretch of the vitellogenin coding sequence, 15% had strongly reduced levels of vitellogenin mRNA. When dsRNA was introduced by intra-abdominal injection in newly emerged bees, almost all individuals (96%) showed the mutant phenotype. An RNA -fragment with an apparent size similar to the template dsRNA was still present in this group after 15 days. Conclusion: Injection of dsRNA in eggs at the preblastoderm stage seems to allow disruption of gene function in all developmental stages. To dissect gene function in the adult stage, the intra-abdominal injection technique seems superior to egg injection as it gives a much higher penetrance, it is much simpler, and it makes it possible to address genes that are also expressed in the embryonic, larval or pupal stages.

The bacterial pathogen Paenibacillus larvae is the causative agent of American foulbrood disease in honeybees (Apis mellifera). A touchdown nested PCR protocol was developed to detect the presence of P. larvae spores directly in honey and hive samples. This approach allows early discovery of the bacteria even at concentrations below pathogenic levels, opening the door to new prophylactic approaches against American foulbrood and real-time epidemiological studies.

In order to survive cold northern winters, honeybees crowd tightly together in a winter cluster. Present models of winter cluster thermoregulation consider the insulation by the tightly packed mantle bees as the decisive factor for survival at low temperatures, mostly ignoring the possibility of endothermic heat production. We provide here direct evidence of endothermic heat production by 'shivering' thermogenesis. The abundance of endothermic bees is highest in the core and decreases towards the surface. This shows that core bees play an active role in thermal control of winter clusters. We conclude that regulation of both the insulation by the mantle bees and endothermic heat production by the inner bees is necessary to achieve thermal stability in a winter cluster.

Aims: To investigate the occurrence of oxytetracycline (OTC) resistance in Melissococcus plutonius, which causes European foulbrood in honeybee colonies. Methods and Results: Strains of M. plutonius were isolated from diseased colonies in England and Wales and tested for resistance to OTC. The minimum inhibitory concentration (MIC) of OTC was also determined for selected isolates. No resistance to the antibiotic was found in any isolate and the average MIC was found to be 3.9 mug ml-1. Melissococcus plutonius was found to be susceptible to both chlortetracycline and tetracycline. Conclusions: No resistance to OTC was found in M. plutonius. Significance and Impact of the Study: This study demonstrated that OTC can continue to be used to treat European foulbrood and that resistance may not explain why some treatments fail.

This paper describes the development of a rule-based expert system to diagnose pests of honeybees (Apis mellifera L.) and to suggest the appropriate treatments. The system can be used as a diagnostic tool for beekeepers and as for educational and extension purposes in bee pathology. It provides a diagnosis based on the description of the external appearance or behavior of the affected colony. Corresponding pictures accompany the most important symptoms and certain measures to be taken are proposed. The expert system was evaluated following the conventional expert system evaluation methodologies. The system was implementing using EXSYS for Microsoft Windows environment.

The Varroa mite, Varroa destructor, is recognized as the most serious pest of both managed and feral Western honey bee (Apis mellifera) in the world. The mite has developed resistance to fluvalinate, an acaricide used to control it in beehives, and fluvalinate residues have been found in the beeswax, necessitating an urgent need to find alternative control measures to suppress this pest. Accordingly, we investigated the possibility of using the fungus, Hirsutella thompsonii, as a biocontrol agent of the Varroa mite. Among the 9 isolates of H. thompsonii obtained from the University of Florida and the USDA, only the 3 USDA isolates (ARSEF 257, 1947 and 3323) were infectious to the Varroa mite in laboratory tests. The mite became infected when it was allowed to walk on a sporulating H. thompsonii culture for 5 min. Scanning electron micrographs revealed that the membranous arolium of the mite leg sucker is the focus of infection where the fungal conidia adhered and germinated. The infected mites died from mycosis, with the lethal times to kill 50% (LT50s) dependent on the fungal isolates. Thus, the LT50s were 52.7, 77.2, and 96.7 h for isolates 3323, 257, and 1947, respectively. Passage of H. thompsonii through Varroa mite three times significantly reduced the LT50s of isolates 257 and 1947 (P LGT 0.05) but not the LT50 of isolate 3323. The fungus did not infect the honey bee in larval, prepupal, pupal, and adult stages under our laboratory rearing conditions. Our encouraging results suggest that some isolates of H. thompsonii have the potential to be developed as a biocontrol agent for V. destructor. However, fungal infectivity against the mites under beehive conditions needs to be studied before any conclusion can be made.

The potential of Hirsutella thompsonii Fisher and Metarhizium anisopliae (Metschinkoff) as biological control agents of the parasitic mite, Varroa destructor Anderson and Trueman was evaluated in the laboratory and in observation hives. In the laboratory, time required for 90% cumulative mortality of mites (LT90) was 4.16 (3.98-4.42) days for H. thompsonii and 5.85 (5.48-7.43) days for M. anisopliae at 1.1 X 103 conidia mm-2. At a temperature (34 +- 1 degreeC) similar to that of the broodnest in a honey bee colony, Apis mellifera L., H. thompsonii (LC90 = 9.90 X 101 (5.86 -19.35) conidia mm-2 at Day 7) and M. anisopliae (LC90 = 7.13 X 103 (2.80 -23.45) conidia mm-2 at Day 7) both showed significant virulence against V. destructor. The applications of H. thompsonii to observation hives resulted in significant mortality of mites, and reduction of the number of mites per bee 21 and 42 days post-treatments. The treatments did not significantly affect the mite population in sealed brood. However, the fungus must have persisted because infected mites were still observed (82.97 +- (0.6)%) 42 days post-treatment. In addition, the fungus was found to sporulate on the host. A small percentage (2.86 +- (0.2)%0) of dead mites found in the control hives also showed fungal infection, suggesting that adult bees drifted between hives and disseminated the fungus. H. thompsonii was harmless to the honey bees at the concentrations applied and did not have any deleterious effects on the fecundity of the queens. Microbial control with fungal pathogens provides promising new avenues for control of V. destructor and could be a useful component of an integrated pest management program for the honey bee industry.

Molecular analyses of social behavior are distinguished by the use of an unusually broad array of animal models. This is advantageous for a number of reasons, including the opportunity for comparative genomic analyses that address fundamental issues in the molecular biology of social behavior. One issue relates to the kinds of changes in genome structure and function that occur to give rise to social behavior. This paper considers one aspect of this issue, whether social evolution involves new genes, new gene regulation, or both. This is accomplished by briefly reviewing findings from studies of the fish Haplochromis burtoni, the vole Microtus ochrogaster, and the honey bee Apis mellifera, with a more detailed and prospective consideration of the honey bee.

We examined the pollen foraging responses of Africanized and European honey bee colonies to hexane extractable compounds of Africanized and European larvae (brood pheromone). Brood pheromone was presented to broodless Africanized and European colonies equalized for numbers of bees, food stores and, empty comb space. The pheromone significantly increased the ratio of pollen to nonpollen foragers returning to colonies. There was no differential pollen foraging response to pheromone racial origin. European colonies in this study had a significantly higher proportion of pollen to nonpollen foragers entering colonies than did Africanized colonies for pheromone and control treatments. The proboscis extension response to sucrose was used to test the sensitivity to sucrose of eight Africanized (most similar to Apis mellifera scutellata Lepeletier) and six European colonies (most similar to Apis mellifera ligustica L.). Individual sensitivity to sucrose has been demonstrated as a neuro-sensory correlate of foraging behavior in European bees such that individuals that forage for pollen have lower response thresholds to sucrose than bees that forage for nectar. Africanized bees were significantly more likely to respond to lower concentrations of sucrose than European bees. We concluded that sucrose response threshold was a poor predictor for comparative foraging behavior of these races because the neuro-sensory systems of the two races may be differentially "tuned" by thresholds to defensive cues.

The present results show that in the ovarioles of a newly emerged (0 day) queen of A. mellifera only two regions may be distinguished: a proximal, short germarium and a very long distal, terminal filament. As the queen matures and gets ready for the nupcial flight, the germarium increases in lenght, advancing towered the distal end, as the terminal filament shortens. The ovarioles of queens ready to mate (6 to 8 days old) have, already one or two ovarian follicles, i.e. a very short proximal vitellarium, but a real vitellogenesis only starts after the fecundation. If the queen does not mate the ovarioles structure is disrupted (12-16 days old). In mated queen eggs the ovarioles present three differentiated regions, from the apice to the basis: a short terminal filament, a medium size germarium, and a very long basal vitellarium. As the eggs are laid, the emptied follicle collapses, degenerates and produces a corpus luteum.

Varroa destructor infestation varies with climate conditions and race of Apis mellifera bees. Africanized bees show greater tolerance to varroa compared to bees of European races. Reproductive ability of female mites, hygienic behavior and grooming behavior are important factors in population dynamics of this parasite. The present study shows the mortality rate of the V. destructor mite in Africanized and Carnica bee colonies in Southern Brazil. The daily proportion of dead and live mite fallen on the bottom of the hive was determined when the total mite population was of adult bees. In Africanized bee colonies the daily proportion of dead mite was 6.30%, while in Carnica bee colonies was 2.11%. The daily proportion of live mite on the bottom of the hive was 2.45% and 0.82% in Africanized and Carnica bee colonies, respectively.

In order to understand the neuronal processes underlying olfactory learning, biophysical properties such as ion channel activity need to be analysed within neurons of the olfactory pathway. This study analyses voltage-sensitive ionic currents of cultured antennal lobe projection neurons and mushroom body Kenyon cells in the brain of the honeybee Apis mellifera. Rhodamine-labelled neurons were identified in vitro prior to recording, and whole-cell K+ and Ca2+ currents were measured. All neurons expressed transient and sustained outward K+ currents, but Kenyon cells expressed higher relative amounts of transient A-type K+ (IK,A) currents than sustained delayed rectifier K+ current (IK,V). The current density of the IK,V was significantly higher in projection neurons than in Kenyon cells. The voltage-dependency of K+ currents at positive membrane potentials was linear in Kenyon cells, but N-shaped in projection neurons. Blocking of voltage-sensitive Ca2+ currents transformed the N-shaped voltage-dependency into a linear one, indicating activation of calcium -dependent K+ currents (IK,Ca). The densities of currents through voltage -sensitive Ca2+ channels did not differ between the two neuron classes and the voltage-dependency of current activation was similar. Projection neurons thus express higher calcium-dependent K+ currents. These analyses revealed that the various neurons of the honeybee olfactory pathway in vitro have different current phenotypes, which may reflect functional differences between the neuron types in vivo.

The protein contents in honey samples of different floral origins, commercialized in several states of Brazil, were determined using the method of Bradford. The spectra of pollen of the honeys collected in those areas were studied, in order to establish the correlation between the different botanical species and the protein contents. The physicochemical properties of the honeys (colour, moisture, pH and acidity, lund test, lugol test, diastase index, reducing and non-reducing sugars and hydroxymethylfurfural contents) were also determined. The colorimetric determination of the protein content of honey samples, using the method of Bradford, was shown to be efficient and it allowed the detection of elevated protein in honey samples of Borreria verticillata, known in Brazil as "vassourinha", from Piaui State.

The biogenic amine neurochemical octopamine is involved in the onset of foraging behaviour in honey bees. We tested the hypothesis that octopamine influences honey bee behavioural development by modulating responsiveness to task-related stimuli. We examined the effect of octopamine treatment on responsiveness to brood pheromone (an activator of foraging) and to the presence of older bees in the colony (an inhibitor of foraging in young bees). Octopamine treatment increased responsiveness to brood pheromone and decreased responsiveness to social inhibition. These results identify octopamine both as an important source of variation in response thresholds and as a modulator of pheromonal communication in insect societies. We speculate that octopamine plays more than one role in the organisation of behavioural development indicating a very high level of integration between the neurochemical system and the generation of complex behaviour.

Previous findings showed that high levels of octopamine and serotonin in the antennal lobes of adult worker honey bees are associated with foraging behavior, and octopamine treatment induces precocious foraging. To better characterize the relationship between amines and foraging behavior in honey bees, we performed a detailed correlative analysis of amine levels in the antennal lobes as a function of various aspects of foraging behavior. Flight activity was measured under controlled conditions in a large outdoor flight cage. Levels of octopamine in the antennal lobes were found to be elevated immediately subsequent to the onset of foraging, but they did not change as a consequence of preforaging orientation flight activity, diurnal pauses in foraging, or different amounts of foraging experience, suggesting that octopamine helps to trigger and maintain the foraging behavioral state. In contrast, levels of serotonin and dopamine did not show changes that would implicate them as either causal agents of foraging, or as neurochemical systems affected by the act of foraging. Serotonin treatment had no effect on the likelihood of foraging. These results provide further support for the hypothesis that an increase in octopamine levels in the antennal lobes plays a causal role in the initiation and maintenance of the behavioral state of foraging, and thus is involved in the regulation of division of labor in honey bees.

Ecosystem services are critical to human survival; in selected cases, maintaining these services provides a powerful argument for conserving biodiversity. Yet, the ecological and economic underpinnings of most services are poorly understood, impeding their conservation and management. For centuries, farmers have imported colonies of European honey bees (Apis mellifera) to fields and orchards for pollination services. These colonies are becoming increasingly scarce, however, because of diseases, pesticides, and other impacts. Native bee communities also provide pollination services, but the amount they provide and how this varies with land management practices are unknown. Here, we document the individual species and aggregate community contributions of native bees to crop pollination, on farms that varied both in their proximity to natural habitat and management type (organic versus conventional). On organic farms near natural habitat, we found that native bee communities could provide full pollination services even for a crop with heavy pollination requirements (e.g., watermelon, Citrullus lanatus), without the intervention of managed honey bees. All other farms, however, experienced greatly reduced diversity and abundance of native bees, resulting in insufficient pollination services from native bees alone. We found that diversity was essential for sustaining the service, because of year-to-year variation in community composition. Continued degradation of the agro-natural landscape will destroy this "free" service, but conservation and restoration of bee habitat are potentially viable economic alternatives for reducing dependence on managed honey bees.

Background: The jack jumper ant (Myrmecia pilosula) is responsible for greater than 90% of Australian ant venom allergy. However, deaths have only been recorded in the island of Tasmania. Objectives: We sought to determine the prevalence, clinical features, natural history, and predictors of severity of M. pilosula sting allergy in Tasmania. Methods: We performed a random telephone survey supported by serum venom-specific IgE analysis, review of emergency department presentations, and follow-up of allergic volunteers. Results: M. pilosula, honeybee (Apis mellifera), and yellow jacket wasp (Vespula germanica) sting allergy prevalences were 2.7%, 1.4%, and 0.6% compared with annual sting exposure rates of 12%, 7%, and 2%, respectively. Similarly, emergency department presentations with anaphylaxis to M. pilosula were double those for honeybee. M. pilosula allergy prevalence increased with age of 35 years or greater (odds ratio (OR), 2.4) and bee sting allergy (OR, 16.9). Patients 35 years of age or older had a greater risk of hypotensive reactions (OR, 2.9). Mueller reaction grades correlated well with adrenaline use. During follow-up, 79 (70%) of 113 jack jumper stings caused anaphylaxis. Prior worst reaction severity predicted the likelihood and severity of follow-up reactions; only 3 subjects had more severe reactions. Venom-specific IgE levels and other clinical features, including comorbidities, were not predictive of severity. Conclusions: Sting allergy prevalence is determined by age and exposure rate. M. pilosula sting exposure in Tasmania is excessive compared with that found in mainland Australia, and there is a high systemic reaction risk in allergic people on re-sting. Prior worst reaction severity (Mueller grade) and age predict reaction severity and might be used to guide management.

The method of application of the antibiotic tylosin (Tylan) for control of oxytetracycline-resistant American foulbrood (Paenibacillus larvae White) was tested in honeybee (Apis mellifera L.) colonies. A powdered sugar mixture with tylosin, applied as a dust, was efficacious in eliminating American foulbrood symptoms at a rate of 200-mg Tylan per 20 g of powdered sugar, applied at weekly intervals for 3 weeks. A second method of treatment consisting of Tylan mixed with granulated sugar and vegetable shortening and applied once as a patty, at an equivalent total dose as the dust method, to diseased colonies also effectively eliminated symptoms of disease. In all colonies treated with patties, however, small hive beetle (Aethina tumida Murray) populations significantly increased, compared with the powder sugar method or untreated controls. Bee populations in patty -treated colonies also were significantly reduced, most likely the result of the invasion and proliferation of adult and larval small hive beetles. Such reduction in colony strength was not seen in dust-treated colonies. Because of the obvious damaging populations of small hive beetles, concerns about development of disease resistance, unknown risks of residues, and lack of support by regulatory agencies for the use of the patty method, the use of the dust method of tylosin is greatly favored over the patty method.

We have found protein composition differences between male, queen and worker antennae, as analyzed by polyacrylamide gel electrophoresis. Female antennal clubs contain three low molecular weight proteins, Siap1 (18 kDa), Siap2 (16 kDa) and Siap3 (14 kDa) with acidic isoelectric points. Tryptic peptide maps obtained by MALDI-TOF mass spectrometry show that Siap1 in worker segment 9 is essentially the same protein as Siap1 in segment 10, and Siap2 from worker segments 9 and 10 are nearly identical. A mass fragment of m/z 477.1 (the 2+ ion for a 952.2-Da peptide) from Siap2 in worker segment A9 was analyzed by electrospray ionization mass spectrometry and found to have the sequence (K/R)-I/L-I/L-I/L-P-V-S-I/L-A -K. This appears similar to the sequence of residues 97-107 of a putative odorant-binding protein from A. mellifera. The male antenna has one major acidic low molecular weight protein, Sim1. It is likely that Siap1-3 and Sim1 are odorant- and pheromone-binding proteins. The segments containing antennal glands in workers and queens show a prominent protein band near 23 kDa, Siap0, which is not seen in any other segment and may be a gland -related protein.

Reverse transcription-PCR assays have been established for a quick, sensitive, and specific diagnosis of acute bee paralysis virus (ABPV), a common virus of the honeybee (Apis mellifera), directly from clinical samples. A 3,071-nucleotide fragment of the ABPV genome, which includes the entire capsid polyprotein gene, was amplified from Austrian, German, Polish, and Hungarian ABPV samples and sequenced, and the sequences were compared. The alignment of a smaller fragment with ABPV sequences from the United States and the United Kingdom revealed nucleotide identity rates between 89 and 96%, respectively. Phylogenetic trees which display the molecular relationship between the viruses of different geographic origin were constructed.

Genetic correlations for behavioral characteristics and forewing length of worker honey bees, Apis mellifera L., were estimated. All characteristics associated with defensive behavior were correlated with each other. The tendency of bees to fly off the combs was correlated with their tendency to run on the combs, and with stinging behavior. Tendency to run was positively correlated with tendency to hang from combs, and with hygienic behavior, but was negatively correlated with forewing length. Forewing length was negatively correlated with hygienic behavior, but it was not significantly correlated with stinging behavior. The correlations obtained suggest that smaller bees have higher activity levels than larger bees. The implications of these results on the adaptive success of Africanized honey bee populations to tropical environments and on selective breeding are discussed.

Imidacloprid is increasingly used worldwide as an insecticide. It is an agonist at nicotinic acetylcholine receptors (nAChRs) and shows selective toxicity for insects over vertebrates. Recent studies using binding assays, molecular biology and electrophysiology suggest that both alpha- and non-alpha-subunits of nAChRs contribute to interactions of these receptors with imidacloprid. Electrostatic interactions of the nitroimine group and bridgehead nitrogen in imidacloprid with particular nAChR amino acid residues are likely to have key roles in determining the selective toxicity of imidacloprid. Chemical calculation of atomic charges of the insecticide molecule and a site-directed mutagenesis study support this hypothesis.

Two organophosphate compounds, coumaphos and diazinon, were examined for effects of sublethal exposure on odor learning and generalization in honey bees, Apis mellifera L. Using proboscis extension response training as a measure of odor learning and discrimination, a series of two experiments tested whether these compounds would inhibit bees from learning a new odor or discriminating between different odors. Bees were exposed to coumaphos or diazinon in acetone applied to the thorax, or to coumaphos or diazinon in hexane injected intracranially. At no dose tested or exposure method used was coumaphos shown to inhibit acquisition of a novel odor stimulus, although it was shown to slightly reduce discriminatory ability when given by intracranial injection. Diazinon had effects on odor learning at several small doses, and a small injected dose was shown to significantly inhibit learning of an odor stimulus paired with a sucrose reward. When bee head acetylcholineasterase activity was measured after dermal applications of both pesticides, only the higher doses of diazinon showed reduced activity, indicating that externally-applied coumaphos shows no significant effect on bee brain acetylcholinesterase activity. These data suggest that acute application of coumaphos has only slight nonlethal effects upon the behavior of honey bees and should have little effect upon bee tasks that involve odor learning.

Crosses were made between queens and drones from 16 different commercial sources of European honeybees to determine if reproductive rates for Varroa destructor differed. Worker brood from four different crosses averaged 4.2 mites per cell and were chosen as the high mite reproduction group. Four others averaged 2.4 mites per cell and were chosen for the low mite reproduction group. A second set of crosses within the high and low mite reproduction groups were made and the worker offspring tested for differences in mite fecundity. Worker brood of the high and low mite reproduction lines did not differ significantly in the average number of mites per cell. The proportion of infested cells with non-reproductive mites also was not affected by selection. These results suggest that the frequency of larval or pupal characteristics that we measured in worker honeybees that might influence mite reproductive rates cannot be increased by selection based on average mite fecundity.

To explore the role of tyramine in the transformation of reproductive states of honeybee workers, brain levels of tyramine and N-acetyltyramine were measured in both normal and queenless workers. Queenless workers had higher tyramine levels and lower N-acetyltyramine levels than normal workers did. Intermediate reproductive workers that were transferred into a normal colony from a queenless colony had intermediate levels of tyramine and N-acetyltyramine. Elevation of tyramine in the queenless workers occurred at an earlier adult stage than elevation of dopamine. Tyramine levels in intermediate reproductive workers returned to the levels seen in normal workers, but dopamine levels in intermediate reproductive workers remained elevated at the same level as in queenless workers. Thus, brain tyramine may be regulated by the colony condition with or without a queen. Injection of an amine uptake inhibitor, reserpine, depleted tyramine and elevated N-acetyltyramine. Distributions of tyramine and dopamine within the brain were distinctively different, whereas distributions of N-acetyltyramine and N-acetyldopamine were similar, suggesting that each functional amine is stored in specific neurosecretory cells and released to the relevant receptor sites but that metabolism into each N-acetylmetabolite is determined by diffusion.

We conducted research on the potential impacts of fluvalinate and coumaphos on honey bee, Apis mellifera L., queen viability and health. Queens were reared in colonies that had been treated with differing amounts of both fluvalinate and coumaphos. Pre- and posttreatment samples of both wax and bees were collected from all of the colonies and analyzed for total concentrations of fluvalinate and coumaphos. All queens were measured for queen weight, ovarial weight, and number of sperm in the spermathecae. The queens treated with high doses of fluvalinate weighed significantly less than low-dose or control queens, but otherwise appeared to develop normally. The highest fluvalinate concentrations were observed in the wax and queen cells of the high-dose group. The developing queens in colonies treated with as little as one coumaphos-impregnated strip for more than 24 h suffered a high mortality rate. Several of the queens showed sublethal effects from the coumaphos, including physical abnormalities and atypical behavior. The queens exposed to coumaphos weighed significantly less and had lower ovary weights than the control group queens. The highest coumaphos concentrations were observed in the queen cells and wax of the high-dose groups.

Alfalfa (=lucerne) flowers require visiting bees to trip the sexual column, thereby providing pollination and subsequent pod and seed set. Previous studies have compared the pollination values of different bee species solely by the speed with which they handle flowers and the proportion of visited flowers tripped. In this greenhouse study, five species of bees, including the three commercially managed U.S alfalfa pollinators, are likewise compared for their floral tripping frequencies. These bee species are also compared for the pod set and mature seed that results from their single visits to virgin flowers. Regardless of the identity of the pollinating bee, tripped flowers had the same probabilities of pod set and seed set. Thus, differences in the single-visit pollination efficiencies of the various bee species are entirely attributable to the proportion of visited flowers that they trip. Females of the alkali bee, Nomia melanderi Cockerell, and the alfalfa leafcutting bee, Megachile rotundata F, tripped 81 and 78% of visited flowers, respectively. Males of these species are significantly less effective (61 and 51%, respectively), but still significantly superior to the honey bee, Apis mellifera L. (22% of visited flowers tripped). These relationships are supported by field data for tripping frequencies. One candidate pollinator, Osmia sanrafaelae Parker, shows promise (44% tripped), but not the congeneric O. aglaia Sandhouse (13% tripped).

To estimate the effective size (Ne) of populations with unequal sex ratio, a well-known formula, Ne=4NmNf/(Nm+Nf), has been frequently used, where Nm and Nf are the numbers of male and female parents, respectively. In this paper, the formula was examined under typical mating systems in animals. It was shown that the formula holds only when there are no variations in the numbers of mates (mating success) of parents of each sex. More appropriate equations were developed by accounting for the variation in mating success. It was found that for animal populations with harem mating system, an equation Ne=4NmNf/(2Nm+Nf) gives a more accurate estimate than the well-known formula. The effective population sizes of several wild, experimental and domestic animals are estimated by applying the derived equations to the published demographic and ecological data.

Dufour's gland (DG) secretion of queens in Apis mellifera is normally caste specific. In queenright (QR) workers it is composed of odd n alkanes, while in queens it also possesses long chain esters. However, glandular expression is plastic since queenless (QL) workers produce a queen-like secretion. Moreover, QR gland incubated in vitro produced these esters, indicating that glandular activity is regulated. We tested the hypothesis that the secretion is an egg marking pheromone. Chemical analysis of the egg coating revealed minute amounts of the queen esters, but neither queen secretion nor the synthetic esters were able to protect worker-laid eggs from policing, refuting the hypothesis. Analysis of abdominal tips further revealed that Dufour's egg secretion is also smeared on the abdominal cuticle, suggesting that its presence on egg surface may be due to passive contamination. Next, we tested the hypothesis that the secretion serves as a queen signal. Indeed queens, but not worker glandular secretion were attractive to workers.

The study evaluated the technical feasibility of distinguishing the different honeybee blood cells by flow cytometric analysis with and without staining by 3 lectins: soybean agglutinin (SBA), concanavalin A (ConA) and wheat germ agglutinin (WGA). Flow cytometric analysis of unstained cells provided a forward scatter-side scatter dotplot with no distinct haemocyte population. Examination of blood samples stained with FITC-labelled ConA or WGA revealed a notable population of fluorescently marked cells on FL1-histograms. Microscopic analysis, run parallel, demonstrated low fluorescence of the granular cells, strong fluorescence of the plasmatocytes, with P1's stained all over their surfaces and P2's with a rather dotted appearance. Prohaemocytes were not stained at all. SBA-FITC did not stain honeybee haemocytes as demonstrated by both the flow cytometric and the microscopic examinations.

Age-related division of labor in honeybees is associated with plasticity in circadian rhythms. Young nest bees care for brood around the clock with no circadian rhythms while older foragers have strong circadian rhythms that are used for sun compass navigation and for timing visits to flowers. Since juvenile hormone (JH) is involved in the coordination of physiological and behavioral processes underlying age-related division of labor in honey bees, we tested the hypothesis that JH influences the ontogeny of circadian rhythms and other clock parameters in young worker bees. Treatments with the JH analog methoprene or allatectomy did not influence the onset of rhythmicity, overall locomotor activity, or the free-running period of rhythmic locomotor behavior. There were, however, significant differences in the onset of rhythmicity, overall locomotor activity, and longevity between bees from different source colonies, suggesting that there is significant genetic variation for these traits. Our results suggest that JH does not coordinate all aspects of division of labor in bees and that coordination of task performance with circadian rhythms is probably mediated by other regulatory systems.

The protein pattern of the venoms of both Apis mellifera and Anthophora pauperata has been analysed using SDS-PAGE to clarify the structure and the degree of similarity of solitary bee venom to the most known social bee venom (Apis mellifera). The data showed that Apis mellifera venom contains eleven bands with molecular weights ranging from 108,000 to 2,000D while Anthophora pauperata venom contains eighteen bands with molecular weights ranging from 108,000 to 6,000D. Venoms of both species showed strong similarities sharing bands with molecular weights 108,000, 93,000, 49,000, 45,000, 8,000 and 6,000D. Anthophora pauperata venom is characterized by a number of bands with molecular weights 37,000, 32,000, 28,000, 25,000, 20,000, 17,000, 13,000 and 10,000D. While venom of Apis mellifera showed two unique bands with molecular weights 3,000 and 2,000D. The effect of the venom of these two species in addition to Bombus morrisoni venom on the blood indices (red blood cells count (RBCs), haemoglobin content (Hb), haematocrit value (HCT), mean cell volume (MCV), mean cell haemoglobin (MCH), mean cell haemoglobin concentration (MCHC)) and erythrocyte osmotic fragility (EOF) showed that there is no significant difference in the blood parameters measured. Whereas, a highly significant decrease in the plasma albumin level was determined in all bee venoms studied.

One approach to understanding proximate and evolutionary mechanisms of social behavior is to analyze mechanisms of neural and behavioral plasticity and their underlying genes. This article deals with such analyses in the honeybee Apis mellifera. The first part reviews the control of age-related division of labor in honeybee colonies with special attention to social, endocrine, and neurochemical factors. The second part reviews progress in studying changes in gene expression that are associated with division of labor, including a brief description of a genomics project that involves a set of 20,000 expressed sequence tags from the honeybee brain and cDNA microarrays for large-scale gene expression analysis. The article concludes by considering some of the general issues associated with studies of genes and social behavior in honeybees.

Upon discovering new sources of food, honeybees and other insects perform learning flights to memorize visual landmarks that can guide their return. Learning flights are longest following initial visits to the food and subsequently decline in duration, which suggests that the investment in learning results from an active decision modulated by a bee's accumulating experience. We document various factors that influence this decision: (1) learning flights reappear when experienced bees encounter a delay in finding food at a familiar place and the durations of such "reorientation flights" increase with the length of the delay; (2) the decay in learning flight duration over visits following such reorientation flights is more rapid than following initial discovery of the food; (3) learning flight duration increases with the visual complexity of the scene surrounding the food, and when spatial relationships among landmarks are unstable; and (4) durations of learning flights at a new feeding place are influenced by the sucrose concentration in the food. Taken together, these experiments suggest that bees can adjust their learning efforts in response to changing needs for visual information and that both sources of spatial uncertainty and the quality of the food influence the value of such information.

The importance of the spatial information which is communicated in the Carnolian Race of the Western Honeybee, Apis mellifera carnica (Pollmann 1879) waggle dance relative to other cues used by bees in finding food sources was investigated. The efficiency of recruitment with and without transmission of direction information in the waggle dance was quantified using artificial, plentiful unscented food sources and hives which were turned to a horizontal position to disrupt orientation of dancing bees and thereby eliminate the spatial information from dances. Transmission of location information seems to improve recruitment effect particularly at large distances. Recruitment declines more rapidly with distance if dances are disoriented, and for large distances it takes a few hours before a foraging group is established. However, this shows that even without dance information, foragers manage to recruit some bees to their food source. This process, however, is so slow that by the time a group of recruits has reached the food source, it may not be worth exploiting any more. Transmission of spatial information thus is especially important if distant food sources which often change in nectar availability are exploited.

American foulbrood (AFB), a severe bacterial disease of honeybee brood, has recently been found in Uruguayan apiaries. Detection of the causative agent, Paenibacillus larvae subspecies larvae, is a very important concern in order to prevent disease dissemination and decrease of honey production. Since spores are the infective forms of this pathogen, in the present work we report the use of polymerase chain reaction (PCR) to detect P. l. subsp. larvae spores from in vitro cultures, larvae with clinical symptoms and experimentally contaminated honey. The set of primers was designed based on the published P. l. subsp. larvae 16S rRNA gene. Using this approach we could amplify the pathogen DNA and obtain a great sensitivity and a notable specificity. Detection limit for spore suspension was a 10-2 dilution of template DNA obtained from 32 spores, as determined by plate count. For artificially contaminated honey, we could detect the PCR product at a 10-3 dilution of template DNA obtained from 170 spores. In addition, when PCR conditions were set to improve specificity, we were able to amplify P. l. subsp. larvae DNA selectively and no cross-reactions were observed with a variety of related bacterial species, including P. l. subsp. pulvifaciens. Since spore detection is very important to confirm the presence of the disease, this method provides a reliable diagnosis of AFB from infected larvae and contaminated honey in a few hours.

The enzyme spectrum of an ectoparasitic mite of the honeybee, Varroa destructor (Anderson and Trueman) was studied using a semi-quantitative method, especially designed for complex samples which have not been purified. Exopeptidases and phosphatases are shown present. A chitinase and enzymes able to transform beta carbohydrates are also present with a large range in the intensity of the reaction. The role of the chitinase can be related to the supply of nutritional needs or/and the piercing and sucking behaviour of the adult parasite. Chitinase activity could be one factor influencing the balance between the parasite and its host.

In the mid-1930s, Karl von Frisch proposed the equivalent of an odor-search hypothesis for honey bee recruitment to food sources. A decade later he switched to the equivalent of a "dance language" hypothesis (though he apparently did not consider his conclusions as hypotheses in either case). The later and more exotic hypothesis rapidly gained acceptance, but it failed its first experimental tests in the mid-1960s; searching recruits did not behave as von Frisch indicated they should under the language hypothesis. His earlier and more conservative odor-search hypothesis meshed better with results obtained in those test experiments. Language advocates then ignored basic precepts of scientific process, rejected and/or ignored results not in accord with their favored hypothesis, and instead repeatedly sought additional supportive evidence. While so doing, they inadvertently accumulated yet more evidence counter to von Frisch's original intent. By invoking ad hoc modifications and qualifications, advocates weakened, rather than strengthened, the hypothesis they continued to embrace. That strict adherence to the language hypothesis has had an unfortunate result; the exclusive investment in that line of research by various governmental agencies has failed to provide practical help to beekeepers or growers in the past half-century.

In the Cape honey bee Apis mellifera capensis, workers lay female eggs without mating by thelytokous parthenogenesis. As a result, workers are as related to worker-laid eggs as they are to queen-laid eggs and therefore worker policing is expected to be lower, or even absent. This was tested by transferring worker-and queen-laid eggs into three queenright A. m. capensis discriminator colonies and monitoring their removal. Our results show that worker policing is variable in A. m. capensis and that in one colony worker-laid eggs were not removed. This is the first report of a non-policing queenright honey bee colony. DNA microsatellite and morphometric analysis suggests that the racial composition of the three discriminator colonies was different. The variation in policing rates could be explained by differences in degrees of hybridisation between A. m. capensis and A. m. scutellata, although a larger survey is needed to confirm this.

Five microsatellite loci were used to determine paternities in six Apis mellifera colonies headed by naturally mated queens. The last inseminating males were identified by collecting and genotyping the mating sign left in the genital tract of each queen. Significant differences in paternity frequencies were observed between males, but the proportion of worker and queen offspring sired by the last inseminating drone did not differ significantly from those of other drones. Each male kept his rank of precedence for the different cohorts, although the variance in subfamily proportions decreased over time, most notably in the colony displaying the lowest level of polyandry. These results suggest that, if sperm competition exists in the honeybee, it does not significantly increase the fitness of the last inseminating drone. The spermatozoa of the different inseminating drones are not totally mixed before they reach the spermatheca, in particular when only few males mate with the queen. The weak difference in the subfamily proportions observed between queen and worker samples confirms that nepotistic interactions are rare.

The effect of an ethanolic extract of propolis, with and without CAPE, and some of its components on cyclooxygenase (COX-1 and COX-2) activity in J774 macrophages has been investigated. COX-1 and COX-2 activity, measaured as prostaglandin E2 (PGE2) production, were concentration -dependently inhibited by propolis (3X10-3-3X102 mugml-1) with an IC50 of 2.7 mugml-1 and 4.8X10-2 mugml-1, respectively. Among the compounds tested pinocembrin and caffeic, ferulic, cinnamic and chlorogenic acids did not affect the activity of COX isoforms. Conversely, CAPE (2.8X10-4-28 mugml -1; 10-9-10-4 M) and galangin (2.7X10-4-27 mugml-1; 10-9-10-4 M) were effective, the last being about ten-twenty times less potent. In fact the IC50 of CAPE for COX-1 and COX-2 were 4.4X10-1 mugml-1 (1.5X10-6 M) and 2X10-3 mugml-1 (6.3X10-9 M), respectively. The IC50 of galangin were 3.7 mugml-1 (15X10-6 M) and 3X10-2 mugml-1 (120X10-9 M), for COX-1 and COX-2 respectively. To better investigate the role of CAPE, we tested the action of the ethanolic extract of propolis deprived of CAPE, which resulted about ten times less potent than the extract with CAPE in the inhibition of both COX-1 and COX-2, with an IC50 of 30 mugml-1 and 5.3X10-1 mugml-1, respectively. Moreover the comparison of the inhibition curves showed a significant difference (p LGT 0.001). These results suggest that both CAPE and galangin contribute to the overall activity of propolis, CAPE being more effective.

Habitat disturbance, particularly of human origin, promotes the invasion of exotic plants, which in turn might foster the invasion of alien -interacting animals. Here we assess whether the invasion of exotic plants - mostly mediated by habitat disturbance - facilitates the invasion of exotic flower visitors in temperate forests of the southern Andes, Argentina. We recorded visit frequencies and the identity of visitors to the flowers of 15 native and 15 exotic plant species occurring in different highly disturbed and less disturbed habitats. We identified three alien flower visitors, the hymenopterans Apis mellifera, Bombus ruderatus, and Vespula germanica. We found significantly more visitation by exotic insects in disturbed habitats. This pattern was explained, at least in part, by the association between alien flower visitors and flowers of exotic plants, which occurred more frequently in disturbed habitats. However, this general pattern masked different responses between the two main alien flower visitors. Apis mellifera exploited almost exclusively the flowers of a subset of herbaceous exotic plants that thrive under disturbance, whereas B. ruderatus visited equally flowers of both exotic and native plants in both disturbed and undisturbed habitats. We did not find any strong evidence that flowers of exotic plants were more generalist than those of native plants, or that exotic flower visitors were more generalist than their native counterparts. Our results suggest that alien plant species could facilitate the invasion of at least some exotic flower visitors to disturbed habitats. Because flowering plants as well as flower visitors benefit from this mutualism, this association may enhance, through a positive feedback, successful establishment of both exotic partners.

Free-flying honeybees, Apis mellifera, learn visual stimuli in the appetitive context of food search. Visual compound stimuli are relevant in nautre as bees learn flower images that consist of many visual elements. We studied whether elemental associations between each visual element and the reinforcement (elemental approach) are enough to explain the solving of visual discrimination problems that raise ambiguity at the elemental level. We asked whether bees could solve three different visual discriminations: (1) positive patterning (A-, B-, AB+); (2) negative patterning (A+, B+, AB-); and (3) biconditional discrimination (AB+, CD+, AC-, BD-). In experiments 1 and 2 bees had to discriminate a yellow-violet chequerboard from the yellow or the violet squares alone. In experiment 3, four different gratings combining one colour (yellow or violet) with one orientation (vertical or horizontal) had to be discriminated. In all three problems binary compounds were trained in such a way that each element appeared equally often as rewarded and nonrewarded. Bees could solve the three discrimination problems. They always chose the reinforced stimulus despite ambiguity at the level of the elements. For solving positive patterning, elemental processing could be used. For negative patterning and biconditional discrimination, nonelemental processing strategies (unique-cue or configural approach) are necessary to account for these results. Although we cannot decide between a configural and a unique-cue interpretation, we can clearly reject purely elemental processing in these cases.

We tested the effects of larval and preforaging rearing environment on the foraging behaviour and sucrose response thresholds of honeybees, Apis mellifera L., derived from high and low pollen-hoarding strains. Bees were reared as larvae and as preforaging adults in colonies containing high and low pollen-hoarding strains, then cofostered in unrelated common wild-type colonies from which to forage. Genotype, but not rearing environment, had strong effects on the likelihood to forage for pollen or nectar, the size of pollen or nectar load, and the concentration of sugar in the nectar they collected. Genotype and rearing environment affected adult wet weights and sucrose concentration response threshold, as measured with the proboscis extension response assay. Bees from the high pollen-hoarding strain were more sensitive to conditions of the rearing environment than were bees of the low strain. High- and low-strain bees produced different colony environments that affected developmental, behavioural and physical traits of the individuals they reared. This demonstrates how genotype and colony environment correlate and affect phenotype.

The longevity of Africanized honeybee workers (Apis mellifera L.) in laboratory conditions was evaluated. Bees from 12 colonies were placed into wooden boxes by groups of 10 to 50 individuals, and maintained in a room under controlled environmental conditions. The workers received candy and water which was renovated daily. A significant interaction between group size and workers source was detected. The mean longevity values recorded for numerically distinct groups from the same colony origin varied from colony to colony (genetic effect). No significant difference of longevity among groups of 20, 30, 40 and 50 individuals was detected. The worst group for experiments on honeybee longevity in laboratory, according to the method used in this research and considering the time wasted to mark the worker bees and to prepare the groups, was that formed by 10 bees.

Forty-five unmanaged honeybee colonies from the south-east of the Iberian Peninsula (Apis mellifera iberica) were selected for analysing their genetic structure using eight microsatellite loci. These colonies were not subjected to management for queen replacement, rearing or migratory movements and previous studies showed that they had mitochondrial DNA (mtDNA) of African origin. Six of the microsatellite loci show intermediate levels of polymorphism with a total number of alleles detected per locus ranging from 4 to 10. Microsatellite data relate these Iberian populations to the African A. m. intermissa, although the presence of some alleles and the observed heterozygosity are characteristic of the European A. m. mellifera, thus corroborating the postulated hybrid origin of A. m. iberica. The results suggest that no recent introgression from Africa has happened and that the populations of A. m. iberica are differentiated in many demes.

We reported on the use of experimental procedures dealing with these behavioural skills in the assessment of pesticide effects. The relevance of the following methods are discussed: (1) use of automatic activity counters set at the hive entrance to establish the balance between outgoing and incoming worker bees; (2) observation of the homing flights of bees; (3) the analysis of the information encoded in the dances of returning foragers; and (4) recording of the conditioned proboscis extension response on restrained bees to evaluate individual learning performances involved in foraging behaviour. These behavioural assays could be developed for sublethal toxicity assessment. However, careful validation of the tests is needed before being used in a routine evaluation procedure. At a minimum, they are valuable tools to understand the mechanisms underlying insecticide toxicity.

The case of a host-parasite relationship may provide a good model to evaluate the costs and benefits of some behaviors, an area in which field data a currently lacking. European (EHB) and Africanized (AHB) honey bees are two Apis mellifera subspecies that coexist in Mexico, the former highly compatible with Varroa destructor, the latter less compatible. Here we examine two mechanisms that could explain the low compatibility between AHB and V. destructor in Mexico: (1) grooming behavior appeared significantly more intensive in AHB colonies, but was nevertheless ineffective; (2) EHB removed 8.03% of the infested brood, while AHB removed 32.46%, especially between 5 and 7 days post-capping. Though the cost of removing infested brood was not different between subspecies, the result, in terms of the amount of removed infested brood, was significantly higher for AHB. For both bees, there is thus a real cost, since removing a pupa results in a lower number of adult bees. We discuss the possibility that the removal of infested brood corresponds with a threshold above which the cost of removal becomes greater than the benefit.

The insecticidal properties of biotin-binding proteins (BBPs) have recently been exploited in transgenic plants. As BBPs have a broad spectrum of insect toxicity, their potential impacts on non-target insects such as honey bees need to be assessed. In this study, the effects of feeding a purified BBP, avidin, to honey bee larvae and adults were determined. A realistic larval dosing regime was developed by estimating the pollen content of brood food in the field and adding avidin to artificial diet at rates that simulated the presence of avidin-expressing transgenic pollen in brood food. Larval survival and development were unaffected by avidin in assays which simulated larvae receiving pollen expressing 0, 4 or 40 muM avidin at concentrations of 164 mug pollen per mg food for the first 2 days and 880 mug pollen per mg food thereafter. Food consumption and survival of adult bees were also unaffected by avidin added to pollen -candy at levels corresponding to pollen expression of 0, 6.7 or 20 muM avidin.

The honeybee dance language, in which foragers perform dances containing information about the distance and direction to food sources, is the quintessential example of symbolic communication in non-primates. The dance language has been the subject of controversy, and of extensive research into the mechanisms of acquiring, decoding and evaluating the information in the dance. The dance language has been hypothesized, but not shown, to increase colony food collection. Here we show that colonies with disoriented dances (lacking direction information) recruit less effectively to syrup feeders than do colonies with oriented dances. For colonies foraging at natural sources, the direction information sometimes increases food collected, but at other times it makes no difference. The food-location information in the dance is presumably important when food sources are hard to find, variable in richness and ephemeral. Recruitment based simply on arousal of foragers and communication of floral odour, as occurs in honeybees, bumble bees and some stingless bees, can be equally effective under other circumstances. Clarifying the condition-dependent payoffs of the dance language provides new insight into its function in honeybee ecology.

In honeybees, Apis mellifera L., the proboscis extension reflex (PER) can be conditioned by associating an odor stimulus (CS) with a sucrose reward (US). As the neural structures involved in the detection and integration of CS and US are bilaterally symmetrical in the bee brain, we ask what respective role each brain side plays in the conditioning process. More specifically, the US normally used in conditioning experiments is the compound stimulation of the antennae (which triggers the PER) and of the proboscis (where bees lick the sucrose solution). Anatomically, the brain receives unilateral US input through each antenna, but bilateral input from the proboscis. By controlling each US component, we show that an antenna-US produces unilateral sensitization, whereas a proboscis-US or a compound-US induces bilateral sensitization. Bees can learn a unilateral odor CS with all three USs, but when a proboscis-US is used, new learning is inhibited on the contralateral side, owing to a possible US-preexposure effect. Furthermore, we show that the antenna-US induces both unilateral and bilateral reinforcement processes, whereas the proboscis-US produces only bilateral effects. Based on these data, we propose a functional model of the role of each brain side in processing lateralized CSs and USs in olfactory learning in honeybees.

Respiration rates in queen-laid and worker-laid eggs of the honey bee, Apis mellifera, were determined for the 3 days of embryonic development. Respiration was quantified by measuring the amount of CO2 produced during 13 h of artificial incubation at four temperature treatments: 28degreeC, 31degreeC, 34degreeC, 36degreeC (+- 0.5degreeC). The mean respiration rates for fertilized and unfertilized eggs from queens were 140.3 +- 4.0 and 141.2 +- 12.2 nl CO2/h/egg, respectively. The mean respiration rate for unfertilized eggs from laying workers was 125.1 +- 6.3 nl CO2/h/egg. Mortality results, as indicated by pre-emergence embryos, showed that 75% developed at 34degreeC compared to 37.5% at 36degreeC. Low temperatures of 28degreeC and 31degreeC had 12.5% and 50% embryos developing to pre -emergence stage, respectively. Respiration results showed significant differences (P = 0.05) between the different days of incubation and temperature treatments, respectively. No significant difference was observed between the fertilized eggs and unfertilized eggs from queens at the same temperature treatment. The comparison of unfertilized eggs from queens and those from laying workers also showed no significant difference. When CO2 output on all the days and temperature treatments were compared, a significant regression (R2 = 0.645) was obtained (P = 0.05).

Mechanical stresses by a narrow glass capillary were applied to unfertilized eggs of honeybees to determine whether the removal of meiotic blocks of the eggs could be caused by simple mechanical stimuli. The treated eggs developed into the anaphase of the first meiotic division at 15 min after treatment, whereas the untreated eggs remained arrested at the metaphase of the first meiotic division. The results of histological examination of the common oviduct showed that its inner widths were sufficiently narrow to cause the distortion of eggs passing through it. The distorted eggs could be fertilized and develop into diploid embryos if they were exposed to the semen immediately (within 30 sec) after egg distortion. However, this would not happen if the distorted eggs were exposed to semen later (30 min). The eggs exposed to the semen but not given mechanical stimuli could initiate the embryonic development with diploid chromosomes. The interval between mechanical distortion and sperm acceptance by eggs in vitro is compatible with that of natural oviposition of fertilized eggs by honeybee queens. These results suggest that egg activation by mechanical stresses in the common oviduct is valid for the natural oviposition in honeybees.

Pharmacological substances such as adenosine deaminase (ADA), collagen, histamine, IgE, myoglobin, and nerve growth factor (NGF) are endogenously present in animals. Research from this laboratory reported decreased levels of ADA, histamine, IgE, and NGF in organs of mice injected with sub -lethal doses of cobra venom. The goal of this research is to observe the levels of ADA, collagen, histamine, IgE, myoglobin, and NGF in certain organs of mice injected with venom from the bee Apis mellifera. Adult Balb/c female mice IM injected with half lethal dose of bee venom were sacrificed after 2 and 8 hours for removal of organs. The homogenates of the organs were assayed by ELISA for ADA, collagen, histamine, IgE, myoglobin, and NGF using respective antisera. Organs from mice injected with PBS were used as controls. It was observed that there were decreased levels of ADA, collagen, histamine, IgE, myoglobin, and NGF in certain organs after 2 h and tremendous decrease after 8 h. This is the first report showing the pharmacokinetics of ADA, collagen, histamine, IgE, myoglobin, and NGF as consequence of honeybee envenomation.

Since primeval times, the inflammatory process has been described in many different ways. Several anti-inflammatory therapies have been used in different biological models. However, in a recent "back to nature move", modern man is searching for natural products with medicinal properties, particularly those obtained from plants and bees. Propolis has been used in folk medicine for a very long time. The many compounds present in propolis require investigation. Physical-chemical analysis studies have not sufficiently established quality standards of propolis containing products. These standards should depend especially on their different pharmacological activities. There are few studies reporting on the in vitro anti-inflammatory activity of propolis containing products. It is necessary to evaluate the anti-inflammatory potential of commercial products containing propolis.

Workers of the Cape honey bee Apis mellifera capensis started to parasitize the African honey bee A. m. scutellata after being introduced into Gauteng (former Northern Transvaal Province) from its native territory, the Cape Province. The A. m. capensis strain that is parasitic has at least two traits that make it a serious pest of the native African bee colonies: workers rapidly develop their ovaries when in a non-capensis colony even when a queen is present, and worker-laid eggs are not killed by worker policing. Here we investigate whether A. m. capensis workers also have special mechanisms to circumvent the guard bees of A. m. scutellata thereby aiding their horizontal transmission between infected and non -infected colonies. We studied the acceptance of non-nestmate A. m. capensis and A. m. scutellata bees by guards of African bee colonies by introducing them to the hive entrance of A. m. scutellata colonies. We used 2 A. m. scutellata discriminator colonies that were both split into a queenright and a queenless portion. Our results suggest that invading workers of A. m. capensis have no special mechanisms to circumvent the African guards. Neither race of the introduced bee nor presence or absence of the queen in the guarding colony affected the proportion of introduced workers accepted. When pooled, 15% of introduced A. m. capensis and 18% of A. m. scutellata non-nestmate workers were accepted by African guards.

Olfaction is of considerable importance to many insects in behaviors critical for survival and reproduction, including location of food sources, selection of mates, recognition of colony con-specifics, and determination of oviposition sites. An ubiquitous, but poorly understood, component of the insect's olfactory system is a group of odorant-binding proteins (OBPs) that are present at high concentrations in the aqueous lymph surrounding the dendrites of olfactory receptor neurons. OBPs are believed to shuttle odorants from the environment to the underlying odorant receptors, for which they could potentially serve as odorant presenters. Here we show that the Drosophila genome carries 51 potential OBP genes, a number comparable to that of its odorant-receptor genes. We find that the majority (73%) of these OBP-like genes occur in clusters of as many as nine genes, in contrast to what has been observed for the Drosophila odorant-receptor genes. Two of the presumptive OBP gene clusters each carries an odorant-receptor gene. We also report an intriguing subfamily of 12 putative OBPs that share a unique C-terminal structure with three conserved cysteines and a conserved proline. Members of this subfamily have not previously been described for any insect. We have performed phylogenetic analyses of the OBP-related proteins in Drosophila as well as other insects, and we discuss the duplication and divergence of the genes for this large family.

We estimated pollen release from hourly stamen samples of a typical pollen flower, Cistus salvifolius, and determined the daily pollen presentation schedule. Half-hourly honey bee (Apis mellifera) pollen foraging on C. salvifolius varied significantly within and between days even though data were only collected on clear sunny days. We found that flower observations varied between flower patches of a very restricted area. We fitted a simple linear model to half-hourly pollen foraging and used the model to predict observed pollen release. For each day, we calculated the optimal time delay between pollen foraging and pollen release. For 9 out of 10 days the time delay was between 28 min and 60 min. The average pollen foraging was about 44 min time delayed compared to average hourly pollen release. Incorporating the time delay in the pollen foraging model to predict pollen release for each of the 10 days, we found a non-significant difference between observed and predicted hourly pollen release for all days. We therefore suggest that pollen foraging of honey bees is determined by the pollen availability and that monitoring of hourly pollen release in entomophilous flowers may be done through simple observations of pollinator foraging.

It is a dictum that Apis mellifera Linnaeus is innocuous in agricultural ecosystems. This study provides the first record of A. mellifera as a significant defoliator of Alnus species. Careful field observations coupled with microscopic examination provided convincing evidence implicating A. mellifera as the cause of leaf perforation on Alnus species in Uganda. Apis mellifera was observed foraging selectively on young Alnus leaves and buds in search of a sticky substance, apparently propolis. In so doing, the bee created wounds that enlarged and caused tattering of Alnus leaves as they matured. Biological surveys indicated that the damage was prevalent and occurred widely, particularly on Alnus acuminata Kunth in Uganda. Incidence of the Apis mellifera damage on Alnus acuminata peaked in the dry season, with up to 90% of leaves emerging per shoot per month damaged, and was lowest in the wet months during peak leaf emergence. Apis mellifera leaf damage was consistently higher on Alnus acuminata than A. nepalensis D. Don., on saplings than mature trees, and on sun exposed than shaded leaves. The activity of honeybees may be detrimental to the productivity of Alnus, yet the substance for which the insect forages on Alnus is a resource with potential economic importance.

We conducted a series of experiments under laboratory conditions to evaluate the feasibility of using a neem-based (Azadirachta indica) insecticide to control varroa (Varroa jacobsoni). The experiments included studies of anti-feeding effects of azadirachtin, the active ingredient of neem-based insecticides, on adult worker honey bees (Apis mellifera); toxicity of azadirachtin to adult workers, worker larvae and associated mites; and the effects of azadirachtin on female V. jacobsoni reproduction. Both commercially formulated and purified azadirachtin were used in the experiments. The results of adult feeding experiments showed that azadirachtin significantly reduced syrup consumption by worker bees (P LGT 0.05) and exhibited a dose response in mortality: with an oral LC50 of 10.87 mug/ml in mite-free bees, 13.69 mug/ml in mite-infested bees, and 41.87 mug/ml for associated mites. The topical LC50 of azadirachtin was 12.53 mug/ml in mite-free bees, 12.31 mug/ml in mite-infested bees, and 35.43 mug/ml in the associated mites. The results of larval feeding experiments showed that worker larvae were more sensitive to azadirachtin than adult worker bees: exhibiting an LC50 of 180.92 ng/ml to purified azadirachtin and 100.13 ng/ml to formulated azadirachtin. More than 90% of treated, normal-appearing, white prepupae and pupae showed precocious and abnormal pigmentation on their mouthparts and other appendages. LC50's of topical applications of formulated azadirachtin were 104.91, 99.12 and 171.37 ng/ml for mite-free worker larvae, miteinoculated larvae and associated mites, respectively. In addition, feeding host larvae with azadirachtin significantly reduced the fecundity of mother mites (P LGT 0.001) as well as egg hatching rate (P LGT 0.001). However, more research is needed to evaluate the reproductive effects of azadirachtin on drones, queens, and varroa under hive conditions.

Various preparations of culture media were used to study their suitability for the production of ascospores and the maintenance of two sexually compatible local isolates of putative Ascosphaera apis (causative agent of chalkbrood) obtained from white honey bee mummies. Morphometric analysis and characterization of the isolates showed that the local isolates were A. apis. Malt yeast with 20% dextrose agar (MY20) was the most suitable medium for ascospore production. Based on mycelium aging, integral rice kernel (IRK) medium was the best for the maintenance of A. apis isolates. Spore-cyst size was the main morphometric feature affected by culture medium. IRK medium induced the development of larger spore cysts.

Using direct RT-PCR, Kashmir bee virus (KBV) was detected in the faecal material of worker and queen honey bees (Apis mellifera). This occurrence implies that KBV could be transmitted horizontally in bee colonies without involving the suspected mite vector, Varroa jacobsoni. The molecular techniques described in this study can be used to certify KBV-free queens sold to beekeepers.

Honeybees have evolved numerous mechanisms for increasing colony-level foraging efficiency, mainly the combined system of scout-recruit division of labour and recruitment communication. A successful forager performs waggle dances on the surface of the comb where it interacts with nectar receivers and dance followers. A forager uses tremble dance when it experiences difficulty finding a receiver bee to unload food upon return to the hive. A bee colony containing numerous subfamilies may increase its efficiency in dance communication if dances are realized by particular groups of specialized individuals or subfamilies rather than by undifferentiated workers. In this study, we determined the subfamily frequencies of waggle and tremble dancers in a colony headed by a naturally mated queen, where the 17 subfamilies can be identified by microsatellite genetic markers. Our results demonstrate that a genetic component is associated with the dance communication in honeybees. More than half of the waggle dances and the tremble dances were performed by workers from only four subfamilies in each case.

Malate dehydrogenase(MDH) is an important enzyme in glycometabolism. MDH of Apis mellifera showed three enzyme active zones, MDH I, MDH II and MDH III. MDH I and MDH III maintained relative stability in different castes and developmental phases, but MDH II was polymorphic, and controlled by three alleles, a, b and c. MDH of Apis cerana was coded by S and F alleles, but some authors reported it is monomorphic. MDH was applied to the studies of A. mellifera, which included several aspects as follows: the number of queen matings, labor division in honeybee societies, the analysis of genetic constitution in honeybee populations and so on. The combination of both MDH and molecular biology will certainly promote honeybee studies.

Modifications in endocrine programs are common mechanisms that generate alternative phenotypes. In order to understand how such changes may have evolved, we analyzed the pupal ecdysteroid titers in two closely related, highly social bees: the honey bee, Apis mellifera, and a stingless bee, Melipona quadrifasciata. In both species, the ecdysteroid titers in queens reached their peak levels earlier than in workers. Titer levels at peak maxima did not differ for the honey bee castes, but in Melipona they were twofold higher in queens than in workers. During the second half of pupal development, when the ecdysteroid titers decrease and the cuticle progressively melanizes, the titer in honey bee queens remained higher than in workers, while the reverse situation was observed in Melipona. Application of the juvenile hormone analog Pyriproxyfen(R) to spinning -stage larvae of Melipona induced queen development. Endocrinologically this was manifest in a queen-like profile of the pupal ecdysteroid titer. Comparing these data with previous results on preimaginal hormone titers in another stingless bee, we conclude that the timing and height of the pupal ecdysteroid peak may depend on the nature of the specific stimuli that initially trigger diverging queen/worker development. In contrast, the interspecific differences in the late pupal ecdysteroid titer profiles mainly seem to be related to caste-specific programs in tissue differentiation, including cuticle pigmentation.

Individually-marked day-old anarchistic (from a line where workers lay eggs at high frequency) and wild-type worker honey bees (Apis mellifera) were introduced to queenless sections of anarchistic or wildtype host colonies housed in observation hives. After 14 days, some introduced workers had activated ovaries, and we then removed the screens separating the queenless from the queenright sections of the observation hives. We then observed all instances of aggression against marked workers for 3 hours. The colonies were then killed and all marked bees retrieved and scored for ovary activation. About 10-40% of workers had activated ovaries. In 3 of 6 colonies, wild-type workers were attacked more often if they had activated ovaries than workers without activated ovaries. Anarchistic workers were more likely to be attacked if they had activated ovaries in one anarchistic host colony only, but in one wild-type host they were more likely to be attacked if they had inactive ovaries. In all colonies there was no significant difference in attack rates between anarchistic and wild -type workers with activated ovaries. This indicates that, like wild-type workers, anarchistic workers are unable to mask their ovary activation from other workers. This study supports the hypothesis some policing occurs via attacks on individuals with activated ovaries, but that this system is much less accurate and acute than the policing system based on egg eating.

To investigate the behavioural response of drone honey bees, Apis mellifera carnica and Apis mellifera scutellata, to the pheromone components isopentyl acetate (IPA) and geraniol, and the non-pheromone octanal, we conducted three different types of experiment: (1), in a glass arena; (2), in a Y-shaped maze; and (3), in a classical conditioning test. IPA caused arousal (more walking and wing beating) and avoidance, and geraniol caused arousal and attraction for drones of both subspecies. In the conditioning experiment the learning success of the drones was high for geraniol, medium for octanal and low for IPA.

Cuticular hydrocarbon profiles of drone honey bees (Apis mellifera carnica) of different ages were compared by gas chromatography. Chromatograms of drones from three different colonies were similar and, despite some variations, showed the same patterns as a function of age. We suggest that in addition to behavioural changes, the surface hydrocarbon profiles of the drones might be used as a cue for the worker bees to discriminate between young and old individuals.

Most commercial almond cultivars are self-incompatible and flowering occurs in early spring when weather conditions are often unfavourable for pollinator flight. Thus, inadequate cross-pollination frequently limits almond yield. We evaluated the effect of pollen dispensers (inserts), fixed onto honey bee hives, on almond fruit set and yield in orchards differing in planting design, i.e. varying in the arrangement and proximity of the main cultivar and pollinizers. Pollen dispensers did not increase fruit-set percentage and yield in the 1:1:1 planting design in which (a), pollinizer rows were planted on either side of the main cultivar rows; and (b), bloom overlap was good between the pollinizers (cv. Carmel and Monterey) and the main cultivar Nonpareil. In contrast, pollen dispensers increased fruit-set percentage and yield in the 1:2:1 (one pollinizer row:two Nonpareil rows:one pollinizer row) planting design in which the branches of the two Nonpareil rows facing each other were more distant from effective pollinizers, and bloom overlap between Nonpareil and one of its pollinizers (Mission) was suboptimal. The increase in fruit set and yield, attributable to the use of pollen dispensers occurred primarily on Nonpareil branches facing the adjacent Nonpareil row. The impact of pollen dispensers was significant at 50 m but not at 150 m from the hive. Although pollen dispensers have been used for more than 60 years, this is the first large-scale study with replication, conducted under commercial conditions that demonstrates their benefit when cross-pollination is limited.

This research was carried out in Ituverava SP Brazil, to evaluate frequency, nectar or pollen hoarding by insects, opening and closing time of flowers in okra crop, Abelmoschus esculentus (Malvaceae) var. Chifre-de -veado, and the effect of their visits in fruit production. Flowers were visited by insects between 7 a.m. to 6 p.m. The flowers were marked and fruit set was evaluated: 10 flowers were protected with a bag and compared to same quantity of unprotected flowers. Okra flowers began opening by 9:40 a.m. to 10 a.m. and closing by 2:45 p.m. and 3:20 p.m. of the same day, when they started to shrivel. The insects observed in nectar hoarding were Hymenoptera (Melipona sp.) and Lepidoptera. In pollen hoarding, insects most frequently were Thysanoptera, Formicidae, Coleoptera and Hymenoptera (Melipona sp. and Apis mellifera). The crop showed 100% auto fertilization and did not require pollinators to produce fruits. However, in flowers visited by insects fruits were heavier, longer and wider.

Honeybee workers, Apis mellifera, usually do not reproduce but can activate their ovaries under queenless conditions to produce male offspring. As an exception to this rule, laying workers of the Cape honeybee, A. m. capensis, parthenogenetically produce diploid female offspring, usually developing into workers and occasionally into queens. Some of such workers can develop into pseudoqueens, which show high ovarial development and a queenlike pheromonal bouquet. Because there is high genetic variance for these characters, this results in an extreme intracolonial selection. This process is governed by a competition for reproductive dominance among workers, leading into a facultative social parasitic reproductive pathway as part of the life history of the Cape honeybee. A. m. capensis workers show an increased potential for invading foreign colonies. Inside of the host colony, parasitic A. m. capensis workers produce queenlike pheromones and swiftly activate the ovaries, despite the presence of a queen. Eventually they establish themselves as pseudoqueens and replace the host queen. The parasitic worker offspring is preferentially fed by the host workers, leading to highly virulent intercastes and thereby completing the social parasitic life cycle of laying A. m. capensis workers. Recently, a particularly virulent parasitic strain of A. m. capensis workers has invaded the neighboring subspecies A. m. scutellata ("capensis calamity"). Because male sexuals are completely lacking in this invasive strain and female reproductives are never reared in infested A. m. scutellata host colonies, this results in reproductive isolation of the parasitic clones from the host gene pool and sets the stage for the evolution of a queenless social parasitic honeybee. The Cape honeybee may therefore constitute a unique subject for studying sympatric speciation of a social parasite.

Synthetic peptides were constructed with the sequence of the first 20 residues of melittin and terminating with a range of different amino acid amides. These were found to have haemolytic and cytolytic activity similar to that of melittin, provided that certain charge constraints were observed. The nature of the 21st residue was not critical except when the residue introduced a negative charge. The presence of at least two positive charges in the molecule was found to be essential for activity. One of these charges could be the amino-terminal amine. Peptides could be inactivated by the addition of a non-acidic presequence which was acetylated at the N-terminus. Introducing a protease cleavable sequence into an N-terminal extension of the peptides produced analogues with low haemolytic activity that could be activated by proteolytic action. A peptide with extra positive charges introduced on the hydrophilic face of the helix possessed a haemolytic activity that was greater than that of melittin.

The dramatic competitive advantage of the African honey bee over European bees in the neotropics comes in large part from their faster rates of colony growth and reproduction. In honey bees, brood production, and thus colony growth, are controlled by the workers. Thus, we tested for genetic differences between African and European workers in their preference for tasks associated with brood production by monitoring individual African and European workers cross-fostered in common colony environments. We additionally examined differences in the age of transition between tasks (age polyethism). Our data provide strong evidence for genetically based differences in a subset of tasks. African workers were more likely to collect and process pollen, the nutrient source for brood. They initiated pollen foraging at a younger age, but this result was not significant after Bonferroni adjustment. African and European workers showed no difference in brood-care task performance, and did not vary in the age at which they performed brood-care tasks. These data suggest that a significant part of the competitive advantage of this major invasive pest can be traced to a small subset of worker behaviors, those involving resource intake.

The parasitic mite Varroa destructor Anderson AMPERSAND Trueman is a major pest of the honeybee Apis mellifera L. throughout the world. Chemical agents currently used for mite control leave contaminating residues and promote pesticide resistance. As an alternative means of control, it would be useful to identify natural substances enabling bees to detect Varroa inside brood cells. These substances could then be used to trigger mite hygienic behaviour by bees. In this study several techniques were used to screen substances that might allow detection of infested brood cells by bees. Gas chromatography-mass spectrometry analysis was performed on substances extracted in dichloromethane from the contents of brood cells. Solid phase microextraction and solid injection were performed on substances obtained from living and dead Varroa, respectively. Electroantennography was performed to assess the sensitivity of olfactory receptors in bee antennae to some of these substances. Principal component analysis based on proportions of cuticular substances allowed discrimination between bees and other cell contents. Foundress Varroa exhibited the greatest dissimilarity to healthy pupae that were used as controls. Immature Varroa and faecal material were intermediate. High molecular weight compounds, mainly dimethylalkanes, were proportionally the most characteristic components of foundress Varroa. This finding suggests that these compounds would be the most apt to induce uncapping of cells infested by Varroa. Solid-phase microextraction and solid injection demonstrated the presence of aliphatic acids, esters, and one alcohol, eicosenol, in Varroa. Electroantennographic recordings showed that mite -resistant bees were more responsive to some acids and one ester. We speculate that these compounds may be involved in recognition of living Varroa by honeybees.

Safety of NeemAzal (azadirachtin 10,000 ppm) was evaluated at different dosages against Apis mellifera Linneaus Foragers. NeemAzal at the highest dosage (800 ppm) was found to be safe to honeybees with 7.58% mortality in direct toxicity test and 0.74% mortality when bees were caged in cotton field after spray. However, in foliage bioassay, it caused 17.19% mortality of foragers. Triazophos at the recommended dosage (2000 ppm) was highly toxic with mortality varying from 71.41 to 100% in different tests.

The malate dehydrogenase (MDH) isozyme in six subspecies of Apis mellifera, i.e., "Zhejiang Agricultural University No.1 A. m. ligustica (Ea), A. m. ssp. (Db), A. m. carnica (Cn), A. m. carpatica (Cp), A. m. caucasica (Cc), and A. m. acervorum (Ac), was studied with isoelectrofocusing polyacrylamide gel electrophoresis (IEF-PAGE), and their genotype frequency, allele frequency, homozygous and heterozygous degree were analyzed. Ea, Cp and Cc showed high homozygous degree, but the allele with the highest frequency was c in Ea; b in Cp; and a in Cc. Db, Cn and Ac are highly heterozygous subspecies, but the frequency differences of the allele a, b and c in Db were less than the others; and the frequencies of the allele a, c were higher, while the allele b was rare in Cn and Ac. There were highly significant differences in the genotype frequency, the allele frequency and the heterozygous and homozygous degree among six subspecies. These differences provided some genetic clues for the discrimination of six subspecies.

A summary is given for the honey bee species (Apis Linnaeus) indigenous to India. Four indigenous species are recognized from the region; Apis cerana, A. dorsata, A. florea and A. andreniformis. All are commonly found in India except for A. andreniformis, which is only known from a few specimens collected in the northeastern boundaries of the country. A dichotomous key is presented to aid the identification of these species and notes given on how to separate them from the introduced western honey bee, A. mellifera.

Chemosensory proteins (CSPs) are ubiquitous soluble small proteins isolated from sensory organs of a wide range of insect species, which are believed to be involved in chemical communication. We report the cloning of a honeybee CSP gene called ASP3c, as well as the structural and functional characterization of the encoded protein. The protein was heterologously secreted by the yeast Pichia pastoris using the native signal peptide. ASP3c disulfide bonds were assigned after trypsinolysis followed by chromatography and mass spectrometry combined with microsequencing. The pairing (Cys(I)-Cys(II), Cys(III)-Cys(IV)) was found to be identical to that of Schistocerca gregaria CSPs, suggesting that this pattern occurs commonly throughout the insect CSPs. CD measurements revealed that ASP3c mainly consists of alpha-helices, like other insect CSPs. Gel filtration analysis showed that ASP3c is monomeric at neutral pH. Using ASA, a fluorescent fatty acid anthroyloxy analogue as a probe, ASP3c was shown to bind specifically to large fatty acids and ester derivatives, which are brood pheromone components, in the micromolar range. It was unable to bind tested general odorants and other tested pheromones (sexual and nonsexual). This is the first report on a natural pheromonal ligand bound by a recombinant CSP with a measured affinity constant.

Anarchistic behaviour is a very rare phenotype of honeybee colonies. In an anarchistic colony, many workers' sons are reared in the presence of the queen. Anarchy has previously been described in only two Australian colonies. Here we report on a first detailed genetic analysis of a British anarchistic colony. Male pupae were present in great abundance above the queen excluder, which was clearly indicative of extensive worker reproduction and is the hallmark of anarchy. Seventeen microsatellite loci were used to analyse these male pupae, allowing us to address whether all the males were indeed workers' sons, and how many worker patrilines and individual workers produced them. In the sample, 95 of 96 of the males were definitely workers' sons. Given that apprxeq 1% of workers' sons were genetically indistinguishable from queen's sons, this suggests that workers do not move any queen-laid eggs between the part of the colony where the queen is present to the area above the queen excluder which the queen cannot enter. The colony had 16 patrilines, with an effective number of patrilines of 9.85. The 75 males that could be assigned with certainty to a patriline came from 7 patrilines, with an effective number of 4.21. They were the offspring of at least 19 workers. This is in contrast to the two previously studied Australian naturally occurring anarchist colonies, in which most of the workers' sons were offspring of one patriline. The high number of patrilines producing males leads to a low mean relatedness between laying workers and males of the colony. We discuss the importance of studying such colonies in the understanding of worker policing and its evolution.

The efficacy of using a support pallet, either with or without an insecticide treatment, and a soil area application of insecticide was evaluated for preventing red imported fire ant, Solenopsis invicta Buren, foraging on apiary equipment. Four replicated treatments were evaluated: 1) a single control pallet and two beehives (hive bodies), 2) support pallet treated with Lorsban-4E(R) (active ingredient chlorpyrifos) under a single pallet with beehives, 3) untreated support pallet with no insecticide application under a single pallet with beehives, and 4) soil area treatment consisted of a Lorsban-4E(R) sprayed 3m2 area with bee hives on a single pallet. Ant activity was determined by placing several olive oil-soaked index cards (2.54cm2) on or next to bee equipment for 45 min once each week for six weeks. Control and untreated support pallets all tested positive for ant activity on the equipment. Lorsban 4E(R) treated support pallets and soil treatments eliminated ant activity on all apiary equipment for up to six weeks after insecticide application. Results showed that some vegetation could grow into natural "bridges" over treated pallets providing ants access to apiary equipment. These results have implications for a variety of quarantined commodities that can be stored on support pallets in S. invicta-infested areas, for example nursery stock, hay bales, and sod.

Habituation, a form of non-associative learning, is observed throughout the animal kingdom. However, in contrast to associative learning, little is known about the underlying molecular mechanisms. Using the appetitive proboscis extension reflex in honeybees, we show that the cAMP-dependent protein kinase A (PKA) in the antennal lobe (AL) is implicated in the graded decline of behavioral response during habituation. Repeated stimulation leads to a slow and gradual increase in PKA activity superimposed on a fast transient PKA activation induced by each stimulus. These temporally distinct components of PKA activation are pharmacologically dissectible and are restricted to the AL on the stimulated side. Whereas the transient PKA activation induced by each stimulus requires monoaminergic transmission, the slow component of PKA activation is mediated by the nitric oxide (NO)/cGMP system. Local manipulation of the slow component of PKA activation in single ALs specifically interferes with the dynamic of habituation on the corresponding side. Our results provide strong evidence that NO/ cGMP -mediated PKA activation in each AL contributes to temporal signal integration during habituation. Dishabituation by a sensory stimulus or spontaneous recovery from habituation does not require the PKA cascade. This provides evidence that the mechanisms underlying dishabituation and spontaneous recovery differ from those underlying temporal signal integration during habituation of the proboscis extension response.

A stepwise-selection multivariate discriminate analysis was performed using forewing angles to discriminate the honey bee (Apis mellifera) samples that were collected from six different regions in Turkey. Eleven angles of forewing venation, A4, B4, D7, E9, G18, J10, J16, K19, L13, N23 and O26 were measured biometrically. Discriminant analysis showed that A4, O26, B4, D7, L13, N23 and E9 angles sufficiently discriminated the samples from different subspecies of Turkish honey bees. The first three-subset out of five canonical discriminant functions explained 96.1% of total variations. All samples collected from central and north-east Anatolia regions were 100% correctly classified into their original regions. The samples of other regions were overlapped with each other. The overall percentage of cases classified correctly was 88.9% (32 out of 36 cases). In conclusion, there are high biometrical variations between different regions of Turkey in terms of forewing angles of honey bees and forewing angles can be used for discrimination of Turkish honey bees.

Nuclear DNA PCR-RFLPs previously found in amplifications of three long ( RGT 5 kbp) anonymous regions of DNA were made analyzable using standard PCR procedures. RFLP analyses were simplified by restricting the amplifications to sections, within each locus, that contained most of the informative polymorphic sites. AluI digests of locus L-1 section 2 (L-1S2) revealed three suballeles of which one was African-specific (Apis mellifera scutellata Lepeletier) and one was east European-predominant (A. m. ligustica Spinola, A. m. carnica Pollman, and A. m. caucasica Gorbachev). Alleles found originally at locus L-2 with AvaI were determined in RFLP analysis of two sections, L-2S1int and L-2S2, resulting in two African-specific and two east European-predominant suballeles. Suballele identity was determined by the combination of banding patterns from both fragments. Polymorphisms revealed by HaeIII in locus L-2 were analyzed in amplifications and digests of L-2S1int, an 830 bp fragment within L-2S1. Seven suballeles were found of which two were African -specific and three were east European-specific or predominant, including one suballele specific to the east European subspecies A. m. caucasica. In locus L-5, RFLPs were detected with HaeIII, DdeI, and SpeI. HaeIII polymorphisms were analyzed by amplification and digestion of fragments L -5S1xt and L-5S1ter. Five suballeles were found of which three were African-specific and one east European-predominant. For DdeI, all five alleles originally found with long PCR could be identified in RFLP analyses of three sections. Two African-specific, one east European -specific, and one west European-predominant (A. m. mellifera L. and A. m. iberica Goetze) suballeles were found. A west European-predominant suballele was also found in RFLP analysis of L-5S3 with SpeI. Allele frequency data from Old World and U.S. populations are presented.

Nuclear DNA RFLPs between African and European honey bees (Apis mellifera L.) were sought by amplifying short (1-2 kbp) and long ( RGT 5 kbp) anonymous regions of DNA and digesting the respective PCR products with a collection of restriction enzymes. Three short and three long regions were each screened with 26-31 enzymes. From a total of 163 locus enzyme combinations (LECs), seven revealed informative polymorphisms. One of these LECs came from one of the three short regions (S-3 with AluI), producing a total of seven alleles, five of which were African-specific. The search for useful RFLPs was far more effective within the long regions. The other six informative LECs came from the three long regions (L-1 with AluI, L-2 with AvaI and HaeIII, and L-5 with HaeIII, DdeI, and SpeI), producing a total of 43 alleles, of which 18 were African-specific, 13 were European -specific, and two were predominantly found in the European samples. Among the European alleles, two were predominantly found in west European honey bee subspecies. Strong associations between alleles generated by pairs of enzymes at a locus were found.

Flying honey bees demonstrate highly variable metabolic rates. The lowest reported values (approximately 0.3 W g-1) occur in tethered bees generating the minimum lift to support their body weight, free-flying 2 -day old bees, winter bees, or bees flying at high air temperatures (45degreeC). The highest values (approximately 0.8 W g-1) occur in foragers that are heavily loaded or flying in low-density air. In different studies, flight metabolic rate has increased, decreased, or remained constant with air temperature. Current research collectively suggests that this variation occurs because flight metabolic rates decrease at thorax temperatures above or below 38degreeC. At 30degreeC, approximately 30% of colonial energy is spent during typical foraging, so variation in flight metabolic rate can strongly affect colony-level energy balance. Higher air temperatures tend to increase colonial net gain rates, efficiencies and honey storage rates due to lower metabolic rates during flight and in the hive. Variation in flight metabolism has a clear genetic basis. Different genetic strains of honey bees often differ in flight metabolic rate, and these differences in flight physiology can be correlated with foraging effort, suggesting a possible pathway for selection effects on flight metabolism.

Agriculture in Australia is highly dependent on insect pollination, in particular from the introduced western honeybee, Apis mellifera. Most agricultural pollination is provided as an unpaid service by feral A. mellifera and native insects. A smaller proportion of agricultural pollination is provided as a paid service by beekeepers. Insect pollination is threatened by misuse of insecticides and the loss of remnant vegetation, but most potently by the likelihood that the honeybee mite, Varroa destructor, will enter the country. Now is the time to prepare for the effect of these changes, and international experience with pollinator decline should serve as a guide. We need to protect and manage our remnant vegetation to protect wild pollinators. Insurance against declining A. mellifera will come through the development of management practices for alternative pollinator species. By developing native insects as pollinators we can avoid the risks associated with the importation of additional introduced species.

Honey bees from the Primorsky region of far-eastern Russia were evaluated for their resistance to Acarapis woodi. Results from a field test in Louisiana showed that Primorsky honey bees showed strong resistance to tracheal mites. The Primorsky honey bees maintained nearly mite-free colonies throughout the experiment while the domestic stocks were ultimately parasitized by high levels of tracheal mites.

We examined the distribution of Varroa destructor on worker and queen brood in colonies of A. mellifera. With both worker and queen hosts present, the mite prevalence value for worker hosts was 75.0+-4.0% (lsmean+-SE), compared to 5.1+-4.0% for queen hosts (P LGT 0.0001). We also examined the response of mites to cuticular extracts of 5th instar worker and queen larvae using arrestment bioassays. In binary-choice tests at 0.5 larval equivalents (Leq), worker extract arrested 84.79+-4.98% of the mites, while queen extract arrested 15.21+-4.98% (P LGT 0.0001). At 0.8 Leq, worker extract arrested 89.75+-4.98%, while queen extract arrested 10.25+-4.98% (P LGT 0.0001). We also measured the repellent activity of royal jelly extract in a repellent bioassay. Royal jelly extract repelled 78.5+-2.6% of mites at 5 mg royal jelly equivalents (Rjeq); 85.6+-3.7% at 10 mg Rjeq; and 89.2+-3.8% at 20 mg Rjeq. The response at each dose was greater than the 10.5+-2.9% mites repelled by solvent controls (P LGT 0.0001). Our findings suggest that the low incidence of mites in queen brood is due, in part, to the repellent activity of royal jelly, and possibly to intrinsic differences between larval chemistries.

This study examined how a honey bee colony supplied additional labor for a foraging task, pollen collection, when the demand for this task was increased. When we experimentally raised a colony's pollen need from one day to the next, we found that the colony boosted the labor devoted to pollen collecting (measured in terms of the number of pollen collection trips per day, P) by a factor of 24.8. The number of pollen foragers (N) was increased (by recruiting and task switching) by a factor of 12.4, while the number of collecting trips per pollen forager per day (T) was increased by a factor of 2.0 (note that P=NXT). The increase in number of pollen foragers was produced mostly (73%) by the recruiting of non -foragers to the task and to a smaller extent (27%) by the switching of non-pollen foragers to the task.

Varroa destructor resistance to pyrethroids has been reported in mainland Europe since the early 1990's. V. destructor was first detected in the UK in 1992 and since then there has been widespread use of the only two authorised pyrethroid treatments. A routine national screening programme for resistance to pyrethroids was established in 2000 and in August 2001 resistance was detected in southwest England. The resistance outbreak was limited to 25 apiaries, was associated with product misuse, and the resistance factors to fluvalinate and flumethrin were approximately 10 fold when compared to susceptible mites. There was no cross-resistance with amitraz, coumaphos or cymiazole. This level of resistance is far lower than that detected following widespread colony collapse in Italy and highlights the importance of the correct use of varroacides and of early detection of resistance to enable its control.

Please note that on page 117 (Journal of Apicultural Research 38(3-4): 117 -123), Summary, should read: "In queenless (not queenright as printed) colonies, larvae of all ages received 124% of the nourishment received in queenright (not queenless as printed) colonies." And: "In queenless (not queenright as printed) colonies, larvae of all ages received 175% of the nourishment in queenright (not queenless as printed) colonies."

To determine the tendency and phenology of reproductive swarming and migration of the honey bee populations of Ethiopia, 240 beekeepers from 57 localities representing different ecological areas of the country were interviewed based on a pre-structured questionnaire. Extent of reproductive swarming and migration, number of swarms per colony, occupation rate of bait hives and periods of swarming and migration were assessed for about 3000 honey bee colonies. Significantly high reproductive swarming proportions were noted for Apis mellifera jemenitica and A. m. scutellata, and low proportions for A. m. bandasii, A. m. woyi -gambella and A. m. monticola. Temporal distribution of swarming varies both within and between subspecies and is related to physiographic and climatic factors of the areas. The proportions of migrated colonies differed significantly among the five subspecies and resource depletion was the most persistent factor associated with migration.

Honey bees (Apis mellifera) and bumble bees (Bombus impatiens) were compared for three aspects of pollinating behaviour on field-grown cucumber (Cucumis sativus) and watermelon (Citrullus lanatus). We measured: (1), diurnal for-aging activity periods (as related to anthesis); (2), floral visitation rates (number of flowers visited per min by individual foragers); and (3), stigmatic pollen deposition (number of pollen grains deposited on stigmas after single bee visits to female flowers). B. impatiens was more effective than A. mellifera for all three parameters on both crops. B. impatiens initiated foraging activity 15-40 min before A. mellifera; both species continued foraging until flowers closed in early afternoon. B. impatiens consistently visited more flowers per min (P LGT 0.001) and deposited equal or greater amounts of pollen (P LGT 0.001) than A. mellifera, particularly during the initial hours of floral anthesis which is when these crops are most receptive to pollination. The data additionally suggest that researchers evaluating different pollinator candidates should consider time-of-day effects when comparing pollen deposition rates between pollinators, as time-of-day had a marked influence on pollen deposition in these studies.

Honey bee semen was stored in green coconut (Cocos nucifera L.) water plus dihydrostreptomycin and in commercial tissue culture media at different temperatures. Glass capillary microtubes of 0.1cm diameter and centrifuge microtubes 0.2ml capacity were used for semen storage. Sperm motility was assessed after 1, 2, 5, 10, 15, 30, 50, 80 and 120 days. Queens were instrumentally inseminated with diluted semen and their laying behavior evaluated. Storage in coconut water shows living sperm until 80 days. However, the queen's laying was normal and resulted in viable worker brood only when semen stored up to 15 days in coconut water medium was used for insemination. Coconut water seems to be an ideal natural diluent for short periods in vitro storage of honey bee semen and can be an appropriate method for genetic improvement programmes for honey bees.

Some colonies of Apis mellifera bees produce much more propolis than others, a trait that could be under genetic control. This possibility was investigated in an experiment carried out from April to July 1999, in the "cerrado" forest reserve Pe de Gigante, Santa Rita de Passa Quatro, Sao Paulo State, Brazil. The objective was to begin a genetic breeding program of bees to improve propolis production and verify the correlation between propolis and honey production. In seven apiaries, 100 colonies of Africanized honeybees originating in swarms and captured in forest reserve "Pe de Gigante" were used. Kruskal-Wallis and Mann-Whitney tests were used. The propolis was collected in an Apis Flora collector. Only 25 colonies produced propolis, 87.45g on average, while the other 75 colonies did not produce propolis. The colonies, producers of propolis were better (P LGT 0.001) in honey production, with an average of 26.98 kg/colony vs 13.93 kg/colony for non-propolised colonies. A positive correlation between propolis and honey production with r=0.422 and P=0.00001256 was found, showing that the bees that produced more propolis also produced more honey. The results show that it is possible to select bees for an increase of propolis production and improve the honey productivity.

High temperature high resolution gas chromatography coupled to mass spectrometry (HT-HRGC-MS) is a powerful analytical tool. In this work we applied this technique to the study of crude extracts of propolis collected near the city of Uberlandia - Minas Gerais State. Eucalyptus trees and native plants from "cerrado" (savannah) were the material sources disposable for the Apis mellifera bees. A lot of known propolis constituents were identified, however, several high molecular weight compounds including lupeol alkanoates were identified for first time in propolis.

A peptide named apisimin was found in honeybee (Apis mellifera L.) royal jelly (RJ). N-terminal sequencing showed that this peptide corresponded to the sequence of a cDNA clone isolated from an expression cDNA library prepared from heads of nurse honeybees. No homology was found between the protein sequence of apisimin with a molecular mass of 5540.4 Da and sequences deposited in the Swiss-Prot database. The 54 amino acids of apisimin do not include Cys, Met, Pro, Arg, His, Tyr, and Trp residues. The peptide shows a well-defined secondary structure as observed by CD spectroscopy, and has the tendency to form oligomers. Isoelectrofocusing showed apisimin to be an acidic peptide.

We investigated pattern discrimination by worker honeybees, Apis mellifera, focusing on the roles of spectral cues and the angular size of patterns, Free-flying bees were trained to discriminate concentric patterns in a Y -maze. The rewarded pattern could be composed of either a cyan and a yellow colour, which presented both different chromatic and achromatic L -receptor contrast, or an orange and a blue colour, which presented different chromatic cues, but the same L-receptor contrast. The non -rewarded alternative was either a single-coloured disc with the colour of the central disc or the surrounding ring of the pattern, a checkerboard pattern with non-resolvable squares, the reversed pattern, or the elements of the training pattern (disc or ring alone). Bees resolved and learned both colour elements in the rewarded patterns and their spatial properties. When the patterns subtended large visual angles, this discrimination used chromatic cues only. Patterns with yellow or orange central discs were generalised toward the yellow and orange colours, respectively. When the patterns subtended a visual angle close to the detection limit and L-receptor contrast was mediating discrimination, pattern perception was reduced: bees perceived only the pattern element with higher contrast.

In honeybee colonies, guards protect their nest from various robbers including bees from other colonies. Infrared thermography showed that the guards and the bees examined by them (examinees) differ considerably in their thermal behaviour according to their particular role in the nestmate recognition process. The thorax surface temperature was on average higher and more variable in the examinees (36.1 degreeC, S.D.=4.14, N=1545, 303 bees) than in the guards (34.0 degreeC, S.D.=2.00, N=1681, 772 bees). During thorough examinations lasting longer than 30 s, more than 60% of the examinees showed phases of intense thoracic heating of more than 2 degreeC (maximum temperature 48.5 degreeC), whereas most guards cooled down. Our data suggest that these examinees heat up their surface to enhance chemical signalling during examinations.

Variability of the cell size and symmetry in the honeycombs has been studied. The distance between opposite corners of cells varies from 4.1 to 7.7 mm (mostly 5.0-5.5 and 6.1-7.0 mm). The asymmetry of cells grows in parallel to increase of their size. The size and asymmetry of cells depend on the space of the nest, thus manifesting the ability of honey bees to control the size of their nest. The mechanism of control of both the nest size and empty space inside it is associated with physiological evaluation of the energy expenditure by leg muscles.

A relatively low diversity of bee pollinators was sampled from a fruit orchard in the Central Plateau of Mexico. The effect of agricultural practices that have occurred in the region for the last 2,000 years was discussed and recommendations for future research were given.

Very little is known about the rate at which pollen grains are mobilized within insect-pollinated crop systems, and this is especially true the for commercial production of field-grown cucumber (Cucumis sativus L.), monoecious muskmelon (Cucumis melo L.), and triploid watermelon (Citrullus lanatus (Thunb.) Matsum. AMPERSAND Nakai). The rates of pollen depletion for these crops were therefore investigated on plots simulating commercial crop production using a mixed honey bee (Apis mellifera L.) and bumble bee (Bombus impatiens Cresson) pollinator complex. At anthesis, staminate cucumber, muskmelon, and watermelon flowers contained on average 10539, 11176, and 30739 pollen grains/flower, respectively. At the time flowers closed in the early afternoon (1300 to 1400 HR), only 61% of the total pollen produced had been removed from staminate cucumber flowers, 44% to 62% from muskmelon, and 81% from watermelon flowers. The results suggest that total pollen production in these crops may not necessarily reflect total pollen availability to floral visitors (bees). However, of the total amount of pollen actually removed per flower, RGT 57% occurred during the 2 h following flower anthesis of cucumber and muskmelon, and RGT 77% occurred during the 2 h following flower anthesis of watermelon. Thus, most of the accessible pollen was removed shortly after anthesis, which is when these crops are most receptive to pollination. Nonviable triploid and viable diploid watermelon pollen were removed at similar rates (P=0.4604). While correlation analyses were not possible for the influence of variable bee abundance on pollen depletion rates, higher bee populations in one year appeared to increase the rate at which pollen grains were removed from staminate flowers.

Bee venom has been reported to exhibit antitumour activity in-vitro and in -vivo. Apoptosis, necrosis and lysis of tumour cells were suggested as possible mechanisms by which bee venom inhibited tumour growth. The aim of this study was to investigate potential mechanisms by which bee venom inhibits K1735M2 mouse melanoma cells in-vitro and B16 melanoma, a transplantable solid melanoma in C57BL/6 mice, in-vivo. The proliferation of K1735M2 cells in-vitro was inhibited by bee venom in a concentration- and time-dependent manner. The inhibition was indicated by the arrest of the cell cycle at the G1 stage, as detected by flow cytometric measurements. The bee venom induced apoptosis-like cell death as identified by histological observations and by DNA fragmentation. In the in-vivo experiments, the bee venom (1.0, 3.0, 9.0 mg kg-1 of body weight, on days 1-12) was injected intraperitoneally into mice 24 h after the mice were inoculated with B16 cells. Inhibition of the solid tumour was observed. Apoptosis of the K1735M2 cells was suggested as the possible mechanism by which bee venom inhibited cell proliferation and induced K1735M2 cell differentiation in-vitro. The in-vivo experiment indicated that bee venom could be used as a chemotherapeutic agent against malignant tumours.

A bioassay was developed to test various aspects of the orientation behaviour of the honey bee ectoparasite, Varroa jacobsoni. The bioassay arena consisted of a petri dish, 60 mm in diameter, in which live honey bee larvae and previously frozen adults were used as hosts. Bioassays were conducted in a dark incubator at 32degreeC for 60 min. Greater numbers of mites parasitized worker larvae than drone larvae, but this trend was not significant. Mites of various ages given a choice between nurse bees and fifth instar worker larvae preferred nurse bees at all ages of mites tested, excluding newly emerged mites. When given a choice between a nurse bee and a pollen forager, V. jacobsoni did not show a preference, and similarly when given a choice between a nurse bee and an adult drone no preference was observed. Finally, when given a choice between a nurse bee extracted with hexane and a non-extracted nurse bee, V. jacobsoni preferred the non-extracted host.

Insect mushroom bodies are brain regions that receive multisensory input and are thought to play an important role in learning and memory. In most neopteran insects, the mushroom bodies receive direct olfactory input. In addition, the calyces of Hymenoptera receive substantial direct input from the optic lobes. We describe visual inputs to the calyces of the mushroom bodies of the honeybee Apis mellifera, the neurons' dendritic fields in the optic lobes, the medulla and lobula, and the organization of their terminals in the calyces. Medulla neurons terminate in the collar region of the calyx, where they segregate into five layers that receive alternating input from the dorsal or ventral medulla, respectively. A sixth, innermost layer of the collar receives input from lobula neurons. In the basal ring region of the calyx, medulla neuron terminals are restricted to a small, distal part. Lobula neurons are more prominent in the basal ring, where they terminate in its outer half. Although the collar and basal ring layers generally receive segregated input from both optic neuropils, some overlap occurs at the borders of the layers. At least three different types of mushroom body input neurons originate from the medulla: (a) neurons with narrow dendritic fields mainly restricted to the vicinity of the medulla's serpentine layer and found throughout the medulla; (b) neurons restricted to the ventral half of the medulla and featuring long columnar dendritic branches in the outer medulla; and (c) a group of neurons whose dendrites are restricted to the most ventral part of the medulla and whose axons form the anterior inferior optic tract. Most medulla neurons (groups a and b) send their axons via the anterior superior optic tract to the mushroom bodies. Neurons connecting the lobula with the mushroom bodies have their dendrites in a defined dorsal part of the lobula. Their axons form a third tract to the mushroom bodies, here referred to as the lobula tract. Our findings match the anatomy of intrinsic mushroom body neurons (Strausfeld, 2002) and together indicate that the mushroom bodies may be composed of many more functional subsystems than previously suggested.

Honeybee defensive behavior is a useful selection criterion, especially in areas with Africanized honeybees (Apis mellifera L). In all genetic improvement programs the selected characters must be measured with precision, and because of this we evaluated a metabolic method for testing honeybee defensive behavior in the laboratory for its usefulness in distinguishing between honeybee ecotypes and selecting honeybees based on their level of defensive responses. Ten honeybee colonies were used, five having been produced by feral queens from a subtropical region supposedly colonized by Africanized honeybees and five by queens from a temperate region apparently colonized by European honeybees. We evaluate honeybee defensive behavior using a metabolic test based on oxygen consumption after stimulation with an alarm pheromone, measuring the time to the first response, time to maximum oxygen consumption, duration of activity, oxygen consumption at first response, maximum oxygen consumption and total oxygen consumption, colonies being ranked according to the values obtained for each variable. Significant (p LGT 0.05) differences were detected between ecotypes for each variable but for all variables the highest rankings were obtained for colonies of subtropical origin, which had faster and more intense responses. All variables were highly associated (p LGT 0.05). Total oxygen consumption was the best indicator of metabolic activity for defensive behavior because it combined oxygen consumption and the length of the response. This laboratory method may be useful for evaluating the defensive behavior of honey bees in genetic programs designed to select less defensive bees.

The mechanisms underlying the control of solution transport rates through the proventriculus in foraging honeybees were investigated in individuals trained to collect defined amounts of sugar solutions. Following feeding, bees were injected either with metabolisable (glucose, fructose, trehalose), or non-metabolisable (sorbose) sugars, in order to distinguish between haemolymph osmolarity and haemolymph sugar levels as factors controlling the solution transport rates through the proventriculus. After a fixed period, workers were dissected in order to measure crop content and haemolymph sugar titers. Between feeding and dissection, the metabolic rate of every investigated forager was measured using open-flow respirometry. Bees injected with metabolisable sugars 15 min after feeding were observed to reduce their solution transport rates through the proventriculus, but injection of non-metabolisable sugars had no influence on them. This suggests that the solution transport rate through the proventriculus is controlled by the concentration of metabolisable compounds in the haemolymph, and not by the haemolymph osmolarity. A period of 10 min after injection of metabolisable sugars was enough to observe reduced solution transport rates. However, if bees were injected only 5 min after feeding, no reduced solution transport rates were observed 10 min after injection.

The control of crop emptying in foraging honeybees was investigated in individuals trained to collect defined amounts of sugar solutions. Following feeding, they were dissected after fixed periods of time in order to measure crop content and haemolymph sugar titers. Between feeding and dissection, the metabolic rate of every investigated forager was measured using open-flow respirometry, so as to assess the effects of both food quality (concentration, molarity and viscosity of the fed sugar solution) and food quantity on the transport rate through the proventriculus. The sugar transport rate through the proventriculus was observed to be mainly dependent on the metabolic expenditure of the individual. Bee foragers were able to precisely adjust the sugar transport rate of their metabolic rates, but under certain conditions, an excess of sugars was transported through the proventriculus, more than needed to cover the bee's energetic demands. This excess depended on the nutritive value and quantity of the fed sugar solution, and on the time after feeding. It did not depend on the metabolic rate of the bee, the molarity, or the viscosity of the fed sugar solution. As long as the bees did not exhaust their crop contents, the haemolymph sugar titers were unaffected by this excess amount transported, by the time after feeding, the concentration and the viscosity of the fed sugar solution. For all feeding conditions assayed, the haemolymph trehalose titer remained constant, while the titers of other haemolymph sugars varied. It is suggested that the trehalose concentration in the haemolymph is regulated in honeybees, and that it represents the controlled variable in the feedback loop responsible for the transport rate through the proventriculus.

The progress of infection of American foulbrood (AFB), Paenibacillus larvae larvae, in honey bee (Apis mellifera) larvae, prepupae, and pupae were studied in in vitro rearings, micro colonies and full-size colonies. P. I. larvae spores in various known numbers (3-1384 spores per larva) were inoculated at a larval age of 24-28 h. The in vitro study suggested that survival time decreased with increasing spore inoculation dose. No larvae inoculated with three spores died before day 6, but 30% of the larvae inoculated with 1384 spores had died at day 4, 36 h before the time of capping (in a bee colony). On day 4, approximately 480 000 bacterial colonies were cultured per larvae inoculated with 1384 spores at a larval age of 24 h. Viable counts of P. I. larvae per larvae from inoculation and four weeks onwards fitted (R2 = 0.917) a standard model for bacterial growth: Iny = b ln (1 + exp (a = rt)), where y is predicted viable count, r is growth rate, t is larval age in hours, and b and a are constants. Bacterial growth rate in the four weeks infection period was estimated to be r = 0.179+-0.030 h-1. In the queenless micro colonies and full-size colonies the first signs of AFB were not visible to human eyes until day 4. By day 3 nurse bees removed 40% and 50% of the inoculated larvae, respectively, indicating that they are able to detect infected larvae before disease symptoms are visible. An early removal behaviour probably is a very important trait to focus on when breeding for resistance against AFB. The removal behaviour of nurse bees in micro colonies was well correlated with removal in full-size colonies. We conclude that, the micro colonies may serve as a labour and time saving model for full-size colonies when testing the removal behaviour of selected bee lines.

We examined whether fruit production in the South American endemic tree Geoffroea decorticans depends on pollinators. Although diverse native pollinators were recorded, Apis mellifera reached RGT 60% of the visits. Honey bees can pollinate efficiently but promote mainly geitonogamous pollination. Geoffroea decorticans is facultatively xenogamous and can produce few fruits from selfing. The best fruit set was produced by hand -xenogamous pollination. Fruit set by hand self- and natural-pollination were similarly less. Although floral display was relatively constant throughout the reproductive season, a decrease was observed in both pollinator activity and fruit production. We conclude that successful fruit production in G. decorticans depends on pollinator activity, but is actually limited by the quality of the pollen transferred by A. mellifera.

The repercussions of concurrent foraging by honey bee (Apis mellifera) and non-Apis bee populations on cross-pollination and seed set in hybrid sunflowers (Helianthus annuus) was investigated. The amount of sunflower pollen on the bodies of honey bees foraging in rows of male-sterile (MS) sunflowers was positively correlated with the size of the non-Apis bee population. The combined population of non-Apis bees and honey bees foraging on male-fertile (MF) and MS sunflowers also was positively correlated to seed set in MS rows. There were more honey bees than non -Apis bees foraging in MF and MS rows, but there was no evidence of competition for resources between the two populations. The size of the honey bee population was positively correlated to the area of open flowers on sunflower capitula, while the non-Apis population remained relatively constant throughout bloom. Results from this study indicate that a combined honey bee and non-Apis bee population might result in better pollination of hybrid sunflowers than either population alone.

We studied the genetic control of the dance dialects that exist in the different subspecies of honey bees (Apis mellifera) by observing the variation in dance form observed in a backcross between two lines that showed widely different dance dialects. To do this we generated the reciprocal of the cross performed by Rinderer and Beaman (1995), thus producing phenotypic segregation of dance forms within a single colony rather than between colonies. Our results are consistent with Rinderer and Beaman (1995) in that inheritance of the transition point from round dancing fwdarw waggle dancing is consistent with control by a single locus with more than one allele. That is, we found one dance type to be dominant in the F1, and observed a 1:1 segregation of dance in a backcross involving the F1 and the recessive parent. However, we found some minor differences in dance dialect inheritance, with the most significant being an apparent reversal of dominance between our cross (for us "black" is the dominant dialect) and that of Rinderer and Beaman (1995) (they report "yellow" to be the dominant dialect). We also found that our black bees do not perform a distinct sickle dance, whereas the black bees used by Rinderer and Beaman (1995) did perform such a dance. However, our difference in dominance need not contradict the results of Rinderer and Beaman (1995), as there is no evidence that body color and dominance for dance dialect are linked.

The pollen choice by native carpenter bees (Xylocopa splendidula) in the Argentine pampas was surveyed by means of the pollen harvest in nests. Samples were taken in January 1996, 1997 and December 1998. The data obtained were compared with data from introduced honey bees, Apis mellifera, in the same region (Telleria, 1993). 16 species belonging to 11 families of Angiosperms are present in the foraging spectrum of X. splendidula. The carpenter bees principally collected pollen from the plants which are isolated or in small populations. In contrast forage plants for honey bees are in dense populations. Such differences may be attributed to different skills needed to exploit the resources, and to displacement of native carpenter bees towards less productive environments, by introduced honey bees.

Bee venom is a complex substance, which acts in several tissues. Although severe allergic reactions have occurred after one or more stings, several deaths have been reported without allergic manifestations, emphasizing the toxic effects of massive poisoning. A number of about 500 stings have been considered necessary to cause death by direct toxicity, but as few as 30 -50 stings have proved fatal in children. Among the major toxic effects are hemolytic anemia, acute renal failure (ARF), and shock. ARF may be due to a common toxic-ischemic mechanism with hypovolemic or anaphylactic shock, pigment tubulopathy (myoglobinuria and hemoglobinuria), or acute tubular necrosis (ATN) from a direct kidney toxicity of the venom. We present a case of rhabdomyolysis and hemolysis with consequent ARF which developed after about 800 bee stings. The patient recovered completely after peritoneal dialysis.

Aims: To investigate effects of introduced honey bees, Apis mellifera L., on the nectar-feeding activity of two species of endemic nectarivorous birds, the Grey White-eye, Zosterops borbonicus mauritianus Gmelin, and the Olive White-eye, Z. chloronothos Viellot, on two endemic flowering trees, Sideroxylon cinereum Lam. and S. puberulum DC. (Sapotaceae), and to examine pollination efficiency of birds and honey bees. Location: An upland heath area on the island of Mauritius, Indian Ocean. Methods: We quantified visitation rates of endemic birds and introduced honey bees at two endemic species of flowering trees. Diurnal variation in nectar standing crop and nectar production was measured. Pollination efficiency of flower visitors was examined using bagging and caging experiments. Results: White-eyes were only nectar-feeding at the two Sideroxylon species early in the morning, stopping when honey bee foraging activity rapidly lowered nectar standing crops. White-eyes continued nectar-feeding at other flowering plant species, exploited less by honey bees, throughout the day. Honey bees were less efficient pollinators of the two Sideroxylon species than white-eyes. Main conclusions: Our results indicate that introduced honey bees could be interfering with endemic interactions between the two Sideroxylon species and the two white-eye species. However, because of lack of a neutral control site without honey bees, we cannot exclude other explanations. We do recommend, although, that honey bees need to be taken into consideration in the future conservation management of Mauritian ecosystems. We suggest that island ecosystems are especially vulnerable to introduced honey bees.

In vitro tests, oxytetracycline (OTC) showed a highly inhibitory effect on spores of Paeniacillus larvae larvae isolated from colonies of honey bee (Apis mellifera) in Taiwan (MIC = 0.125 mug/ml), but showed no sporicidal effect. In field tests, honey bee colonies were medicated with OTC syrup to determine its effectiveness in prevention of American foulbrood (AFB) in young larvae. Results showed that two doses of OTC syrup, 125 mg/colony and 50 mg/colony, prevented AFB signs for a period of, at least, 9 days and 3 days, respectively. Colonies with a mild AFB infection treated with hive replacement recovered from the disease, and no AFB recurrence was seen in an investigation period of 15 weeks. In addition to hive replacement, colonies with a heavy infection should also be medicated with 125 mg of OTC on the 5th day post-replacement.

This experiment was conducted in a plum orchard in which half-and-half peach root-stocked plums and California plums are cultivated. Two colonies of Apis cerana and five colonies of Apis mellifera were moved in before flowering to investigate the pollinating ecology of the two pollinator species. The plum blooming period was 21 d, and there were more than six flowers per twig from the 7th to 12nd days after blooming. The pollination activity of A. cerana on plums peaked between 0900 and 1100 h, while that of A. mellifera peaked between 1100 and 1300 h, coinciding with the time period of daytime gathering of maximal amount of plum pollen for both species. The number of foraging bees on blooming plums decreased with increasing distance from plums to the beehive. However, the high-stem planting surrounding the orchard created a wall effect that resulted in similar number of foragers on plums 50 and 150 m from the beehive. During the plum blooming period, the total number of non-plum pollen pellets gathered by A. cerana has a 13.5-fold increase compared with that of plum pollen pellets. But the number of plum pollen pellets gathered by A. mellifera was 2.6 fold higher than the number of non-plum pollen pellets. The final fruit sets were 8% and 13% of the initial number of flowers for bagged and non-bagged twigs, respectively, for peach root-stocked plums, and were 0% and 5%, respectively, for California plums.

An artificial method was developed for rearing 1-day-old worker honey bee (Apis mellifera) larvae to the adult stage in the laboratory. The proportion of adult emergence was 57.1%. This method subsequently was used to study the effects of oxytetracycline (OTC) on larval growth and development. With a concentration of 25 ppm OTC in the diet, larval and postdefecation mortalities, and larval growth rates were similar to those of the controls, while doses higher than this retarded larval growth and caused higher mortality. Feeding with 0.2 ppm OTC effectively reduced larval and postdefecation mortalities of larvae inoculated with 4.5 X 105 spores/ml of Paenibacillus larvae larvae. But it appeared in 1% of American foulbrood (AFB) individuals. When fed 1.0 ppm OTC and spores, no additional mortalities or AFB-infected individuals were found. This reveals that a low concentration of OTC can effectively protect young larvae from P. l. larvae infection.

This paper addresses, what determines that experienced forager honeybees return to places where they have previously exploited nectar. Although there was already some evidence that dance and trophallaxis can cause bees to return to feed, the fraction of unemployed foragers that follow dance or receive food from employed foragers before revisiting the feeder was unknown. We found that 27% of the experienced foragers had no contact with the returning foragers inside the hive. The most common interactions were dance following (64%) and trophallaxis (21%). The great variability found in the amount of interactions suggests that individual bees require different stimulation before changing to the foraging mode. This broad disparity negatively correlated with the number of days after marking at the feeder, a variable that is closely related to the foraging experience, suggesting that a temporal variable might affect the decision-making in reactivated foragers.

Honeybee colonies (Apis mellifera) maintain temperatures of 35-36degreeC in their brood nest because the brood needs high and constant temperature conditions for optimal development. We show that incubation of the brood at the level of individual honeybees is done by worker bees performing a particular and not yet specified behaviour: such bees raise the brood temperature by pressing their warm thoraces firmly onto caps under which the pupae develop. The bees stay motionless in a characteristic posture and have significantly higher thoracic temperatures than bees not assuming this posture in the brood area. The surface of the brood caps against which warm bees had pressed their thorax were up to 3.2degreeC warmer than the surrounding area, confirming that effective thermal transfer had taken place.

In this paper, the floral biology and pollination ecology of Salvia splendens are described. All flower characteristics (red corolla, large tubular flowers with abundant but dilute nectar) indicate that S. splendens is adapted to hummingbird pollination. Honeybees, however, were also found to be good pollinators of this plant. Apis mellifera was equally effective in pollinating S. splendens as hand pollination and open pollination, resulting in a 300% increase in seed set compared with bagged control plants. The much smaller stingless bee Tetragonisca angustula was not an effective pollinator of these flowers since during visitation its body failed to touch the stigma. Although pollination seemed not to be the only limiting factor in seed production, external pollinators enhance seed production in S. splendens, and Apis mellifera is an effective, commercially available pollination agent of this economically important ornamental plant.

This study used 15 beehives: five with Africanized queens sisters (Apis mellifera), five with Italian queens sisters (Apis mellifera ligustica), and five with Carniolan queens sisters (Apis mellifera carnica). The queens were fertilized naturally. This experiment was performed in the apiary of the Botucatu School of Veterinary Medicine and Animal Husbandry, UNESP, State of Sao Paulo, Brazil. The following data were obtained from the foraging bees: venom quantity in reservoir, 0.117+-0.015, 0.139+ -0.020, and 0.147+-0.024 (mg); venom quantity liberated in extraction apparatus, 0.073+-0.012, 0.057+-0.011 and 0.059+-0.013 (mg); and sting electro stimulus threshold (volts), 10.75+-1.37, 15.11+-2.00, and 15.01+ -1.63 for Africanized, Italian X Africanized and Carniolan X Africanized, respectively. The Africanized honeybees possess less venom in reservoir than the European hybrids (Carniolan and Italian). However, they liberated a larger quantity of venom in the extraction apparatus and required lower electro stimulus threshold to promote stinging.

Until recently, African and European subspecies of the honeybee (Apis mellifera L.) had been geographically separated for around 10,000 years. However, human-assisted introductions have caused the mixing of large populations of African and European subspecies in South and Central America, permitting an unprecedented opportunity to study a large-scale hybridization event using molecular analyses. We obtained reference populations from Europe, Africa, and South America and used these to provide baseline information for a microsatellite and mitochondrial analysis of the process of Africanization of the bees of the Yucatan Peninsula, Mexico. The genetic structure of the Yucatecan population has changed dramatically over time. The pre-Africanized Yucatecan population (1985) comprised bees that were most similar to samples from southeastern Europe and northern and western Europe. Three years after the arrival of Africanized bees (1989), substantial paternal gene flow had occurred from feral Africanized drones into the resident European population, but maternal gene flow from the invading Africanized population into the local population was negligible. However by 1998, there was a radical shift with both African nuclear alleles (65%) and African-derived mitochondria (61%) dominating the genomes of domestic colonies. We suggest that although European mitochondria may eventually be driven to extinction in the feral population, stable introgression of European nuclear alleles has occurred.

The insect visitors of flowers in nine weeds species were studied in the Botanical Garden of Santiago de Cuba, Eastern Cuba, during 1993 (March - June, spring season) and 1994 (January - March, end of winter and beginning of spring season). About 50 hours of collecting efforts were made at three times (0900-0930 hr in 1993; 0900-0930 hr, 1200-1230 hr and 1500-1530 hr in 1994). More than 140 species of at least 37 families were found; Hymenoptera dominated (with more than a half of specimens), followed by Diptera, Coleoptera and Lepidoptera. Among Hymenoptera, bees (Apoidea) were the largest group, especially Apis mellifera L; followed by wasps (Vespidae, Pompilidae, Sphecidae) and ichneumon flies (Ichneumonidae); Microhymenopterans were not sampled. Hymenopterans of each weed were compared for diversity, similarity, dominant and subdominant species, visitation time, sampling efficiency, etc. Each plant species had a particular Hymenoptera complex, almost one third of which were natural enemies of agricultural pests, and most are believed to be potential pollinators. Closely related species showed similar patterns of daily activity, with a peak at 0900-0930 hr for all plant species. Second grade polynomial equations were the best fitted models to describe the relationships between number of species and number of specimens, and between total number of species and number of samples (R2 = 0.9734 and R2 = 0.9573, p LGT 0.01). The role of weeds in the biodiversity of the agroecosystems is analyzed; as well as the effectiveness of this collection method to study Hymenoptera.

Propolis, a beehive product widely used in folk medicine as an antiinflammatory agent, has been attracting researchers' attention to scientifically elucidate its biological properties and therapeutic activities. The aim of this paper was to study the possible effect of propolis on natural killer activity, since propolis immunomodulatory action has been suggested, especially on non-specific immunity. Propolis was produced by africanized honeybees (Apis mellifera L.), collected throughout a whole year, and pooled by season. Hydroalcoholic solutions of propolis were prepared with each pool and administered to rats by gavage over three days. Natural killer activity of non-adherent spleen cells was evaluated by the 51Cr-release cytotoxicity assay against Yac-1 target cells. Our results indicated that the natural killer activity was increased in spleen cells from propolis-treated animals. There were no significant differences related to the seasonal effect on the immunomodulatory action of propolis.

This study investigated the antibacterial activity of propolis produced by A. mellifera and Brazilian stingless bees, called "meliponineos". Susceptibility tests to ethanolic extracts of propolis (EEP) were performed using bacterial strains (Staphylococcus aureus, Enterococcus sp, and Escherichia coli) isolated from human infections. Dilution of EEP in agar (%v/v) was used for determination of minimal inhibitory concentration (MIC). The stingless bee species (and common names) were: Nannotrigona testaceicornis ("Irai"), Tetragonisca angustula ("Jatai"), Trigona spinipes ("Arapua"), Scaptotrigona sp ("Tiuba"), Partamona sp ("Cupira"), Melipona scutellaris ("Urucu"), Melipona sp ("Manduri"), and Melipona mandacaia ("Mandacaia"). EEP inhibitory efficiencies according to bacterial strains were: S. aureus - "Cupira" RGT "Manduri" = A. mellifera RGT "Urucu" RGT "Mandacaia" RGT "Irai" RGT "Tiuba" RGT "Jatai" RGT "Arapua" = Ethanol; Enterococcus sp - "Cupira" RGT "Manduri" RGT A. mellifera RGT "Mandacaia" RGT "Urucu" RGT "Tiuba" RGT "Jatai" RGT "Arapua" = Ethanol; E. coli - "Manduri" RGT "Jatai" RGT Ethanol RGT A. mellifera RGT "Urucu" RGT "Cupira" RGT "Irai". Propolis produced by "Cupira" and "Manduri" bees showed higher antibacterial activity than A. mellifera.

In the honeybee, isopentyl acetate and 2-heptanone are described as alarm substances. We asked whether both substances have a similar role by testing the effect of their exposure on the appetitive proboscis extension reflex and on the aversive stinging reflex. In the appetitive context of sucrose stimulation no differences were found between isopentyl acetate and 2-heptanone. Small amounts of isopentyl acetate or 2-heptanone (3 mul of 1:9 dilution) yielded a response similar to that of a non-exposed control. Larger amounts of both substances (125 mul of 1:9 dilutions) as well as mixtures led to a decrease of responsiveness to sucrose. In the aversive context of electrical stimulation, significant differences between isopentyl acetate and 2-heptanone were found. Exposure to a small amount of isopentyl acetate (3 mul of 1:9 dilution) or to a large amount of 2-heptanone (125 mul of 1:9 dilution) led to an increase of responsiveness to the electric shock. Larger quantities of isopentyl acetate (125 mul of 1:9 dilution) decreased the responsiveness to the shock. 2-Heptanone never decreased the responsiveness to the shock. Our results indicate that isopentyl acetate and 2-heptanone have different functions even if both are capable of evoking deterrent responses in a defensive context.

Undertakers are a specialized task group of honey bees that remove dead bees from the colony. The mean adult age of undertakers is 12.5 days; this is similar to that of other specialized task groups, such as guards. The mean number of undertakers in colonies was 544. However, because the number of bees expressing this behavior is dependent on the demand for task performance, undertaker estimates vary depending on the experimental technique. Increasing the demand for undertaking resulted in more bees engaging in the task. Depleting the number of undertakers by removal of bees carrying corpses resulted in new bees assuming undertaking duties. These results support a response-threshold model for engagement of worker bees in task performance.

Many hypotheses attempt to explain why queens of social insects mate multiply. We tested the sex locus hypothesis for the evolution of polyandry in honey bees (Apis mellifera). A queen may produce infertile, diploid males that reduce the viability of worker brood and, presumably, adversely affect colony fitness. Polyandry reduces the variance in diploid male production within a colony and may increase queen fitness if there are non-linear costs associated with brood viability, specifically if the relationship between brood viability and colony fitness is concave. We instrumentally inseminated queens with three of their own brothers to vary brood viability from 50% to 100% among colonies. We measured the colonies during three stages of their development: (1) colony initiation and growth, (2) winter survival, and (3) spring reproduction. We found significant relationships between brood viability and most colony measures during the growth phase of colonies, but the data were too variable to distinguish significant non-linear effects. However, there was a significant step function of brood viability on winter survival, such that all colonies above 72% brood viability survived the winter but only 37.5% of the colonies below 72% viability survived. We discuss the significance of this and other "genetic diversity" hypotheses for the evolution of polyandry.

A swarm of honeybees (Apis mellifera) is capable of selecting one nest-site when faced with a choice of several. We adapt classical mathematical models of disease, information and competing beliefs to such decision -making processes. We show that the collective decision may be arrived at without the necessity for any bee to make any comparison between sites.

Within an anonymous region of honey bee DNA (locus 227) digested with AluI, informative restriction fragment-length polymorphisms (RFLP) were found in Southern blots with a cloned honey bee DNA probe. The probe was subcloned, so that smaller sections of the locus could be analyzed with the polymerase chain reaction (PCR). Further screening of these amplified sections revealed additional useful RFLPs with HinfI. The informative AluI and HinfI polymorphic sites were mapped to a narrow section of the original probe. A total of 14 sub-alleles was found in this region of which five were found only or predominantly in our African samples (Apis mellifera scutellata Lepeletier), three were found only or predominantly in our east European samples (A. m. ligustica Spinola' A. m. carnica Pollman, and A. m. caucasica Gorbachev), one was found predominantly in our west European samples (A. m. mellifera L. and A. m. iberica Goetze). Significant associations were found between the AluI and HinfI sub -alleles, reinforcing their subspecies group specificity.

Twenty-four honeybee (Apis mellifera) colonies were used to monitor the efficacy of a solution of 2.9% oxalic acid (OA) and 31.9% sugar against the mite Varroa destructor. Mite mortality was established prior to and after OA treatments, which were conducted in August and September. The treatments resulted in 37% mite mortality as opposed to 1.11% in the controls. OA treatment conducted in September on previously untreated colonies resulted in 25% mite mortality. OA treatments in October and November resulted in approximately 97% mite mortality. These results suggest that OA is effective during the broodless period and less effective when applied to colonies with capped broods. The possible use of OA against the Varroa mite in honeybee colonies as an alternative to routine chemical treatments is discussed.

Two distinct neuronal pathways connect the first olfactory neuropil, the antennal lobe, with higher integration areas, such as the mushroom bodies, via antennal lobe projection neurons. Intracellular recordings were used to address the question whether neuroanatomical features affect odor -coding properties. We found that neurons in the median antennocerebral tract code odors by latency differences or specific inhibitory phases in combination with excitatory phases, have a more specific activity profile for different odors and convey the information with a delay. The neurons of the lateral antennocerebral tract code odors by spike rate differences, have a broader activity profile for different odors, and convey the information quickly. Thus, rather preliminary information about the olfactory stimulus first reaches the mushroom bodies and the lateral horn via neurons of the lateral antennocerebral tract and subsequently odor information becomes more specified by activities of neurons of the median antennocerebral tract. We conclude that this neuroanatomical feature is not related to the distinction between different odors, but rather reflects a dual coding of the same odor stimuli by two different neuronal strategies focusing different properties of the same stimulus.

A laboratory bioassay was developed to measure the pathogenicities of isolates of mitosporic fungi to Varroa destructor, an ectoparasite of the European honeybee, Apis mellifera. Forty isolates of entomopathogenic fungi were assessed against V. destructor in a single-dose experiment (conidial concentration 1X108 ml-1) at 25degreeC and 100% RH. The fungal species were Verticillium lecanii (nine isolates), Hirsutella spp. (16 isolates), Paecilomyces spp. (three isolates), Beauveria bassiana (four isolates), Metarhizium spp. (six isolates), and Tolypocladium spp. (two isolates). All isolates could infect and kill V. destructor and 26 caused mean times to death of less than 100 h. Control (Tween-treated) mortality was 5% at 7 days post-treatment. Nineteen isolates were also examined for side effects against bees. Caged bees sprayed with conidial suspensions (1X108 ml-1) of seven of these isolates died within 14 days. However, not all mortality could be attributed to fungal infection as confirmed by sporulation; the mortality of control bees was 27%. Nine isolates were selected for further examination against V. destructor at 30degreeC and 40% RH to simulate the conditions in bee colonies. Of these, three isolates of M. anisopliae, one of V. lecanii, and one of B. bassiana killed 100% of V. destructor within 7 days at a conidial concentration of 1X108 ml-1. One isolate of M. anisopliae also killed 97% of V. destructor within 7 days at a conidial concentration of 1X106 ml-1. These results indicate that entomopathogenic fungi have potential as microbial control agents of V. destructor in honeybee colonies.

The implication of Apis mellifera in the production of Cucurbita maxima in both cropping systems, plants under cover, excluding any insect visit, and plants with free pollination allowed, were studied. Differences between treatments were observed. Plants which received Apis mellifera visits produced more fruits, of higher weight and with a higher number of seeds. The influence of floral attractiveness and the number of flowers per plant were taken into account in visits frequency. Pollen/ovule ratios defines C. maxima as facultatively xenogamous. Results indicate that a controlled pollination has a high production and a better fruit quality. Considering that the natural pollinators of Cucurbita, Xenoglossa and Peponapis are distributed in a reduced area of America, the honey bee seems to be the best option in places where these pollinators are not present.

Honeybee workers (Apis mellifera) may be classified as either short-lived summer bees or long-lived winter bees in temperate zones. The protein status appears to be a major determinant of honeybee lifespan, and the lipoprotein vitellogenin seems to play a crucial role. Here, we give a review of the vitellogenin in honeybee workers, and present a data-driven mathematical model describing the dynamics of this representative protein in the individual bee as a function of its task profile under various regimes. The results support the hypothesis that vitellogenin is a true storage protein that is utilized for various metabolic purposes including the synthesis of brood food. Except for workers having been foragers for many days, they also suggest that the previous life histories of workers do not constrain them from becoming winter bees as long as they get ample food and time to build up their protein reserves before wintering. The results also indicate that it may not be necessary to introduce the ovary as a storage organ for vitellogenin in order to generate normal winter bees. The insights gained from these results are then discussed in a broader gerontological and life history context. Remarkably similar features concerning regulation of ageing in Caenorhabditis elegans, Drosophila melanogaster and honeybees are pointed out and discussed. Furthermore, we show that in contrast to the "mutation accumulation" and the "antagonistic pleiotropy" evolutionary theories of ageing, the "disposable soma" theory is capable of explaining the bimodal longevity distribution of honeybees when interpreted in a group selection context. Finally, by showing that depletion of nutrient stores can be actively controlled by pathways connected to regulation of ageing, we strengthen the claim that age-based division of labour, with performance of risky tasks delayed until late in life by workers with depleted nutrient stores, may have evolved as an energy-saving mechanism in insect colonies.

Enzyme-cleaved antibodies are used widely for the treatment of envenoming. Such products should comprise only 'highly pure' immunoglobulin fragments since Fc or other contaminating protein fragments or their aggregates may lead to side effects. The digestion of ovine antiserum and its purified IgG were investigated using pepsin and trypsin. Trypsin was effective at digesting purified IgG but unsuitable for the direct digestion of serum. In contrast, pepsin was highly effective at digesting all unwanted serum components to low molecular weight (ltoreq 13 kDa) fragments while leaving the apprx 100-kDa F(ab')2 intact. The optimum pH for pepsin digestion was between 3.25 and 3.50. The effects of salt concentration and pH on the digestion products were investigated by size exclusion chromatography under various conditions, which revealed a pH-dependent aggregation of some of the low molecular weight Fc and non-IgG fragments. These high molecular weight aggregates were not shown by SDS-PAGE. Unwanted low molecular weight fragments could be removed simply by diafiltration with a 30-kDa nominal molecular weight cutoff membrane and piperazine buffer (containing 150 mM NaCl, pH 6), leaving an F(ab')2 solution contaminated only with some pepsin and a small amount of the aggregated low molecular weight fragments. These highly acidic contaminants were then removed easily using an anion exchanged column and the F(ab')2 produced following a subsequent concentration step was essentially free from pepsin and aggregates with a purity of over 96% and a yield of 19.3 g F(ab')2/l serum. This novel, high yield method for processing serum to highly pure F(ab')2 avoids salt precipitation and centrifugation and should be suitable for large-scale production.

A rapid procedure for the identification of Paenibacillus larvae subsp. larvae, the causal agent of American foulbrood (AFB) disease of honeybees (Apis mellifera L.), based on PCR and restriction fragment analysis of the 16S rRNA genes (rDNA) is described. Eighty-six bacterial strains belonging to 39 species of the genera Paenibacillus, Bacillus, Brevibacillus, and Virgibacillus were characterized. Amplified rDNA was digested with seven restriction endonucleases. The combined data from restriction analysis enabled us to distinguish 35 profiles. Cluster analysis revealed that P. larvae subsp. larvae and Paenibacillus larvae subsp. pulvifaciens formed a group with about 90% similarity; however, the P. larvae subsp. larvae restriction fragment length polymorphism pattern produced by endonuclease HaeIII was found to be unique and distinguishable among other closely related bacteria. This pattern was associated with DNA extracted directly from honeybee brood samples showing positive AFB clinical signs that yielded the restriction profile characteristic of P. larvae subsp. larvae, while no amplification product was obtained from healthy larvae. The method described here is particularly useful because of the short time required to carry it out and because it allows the differentiation of P. larvae subsp. larvae-infected larvae from all other species found in apiarian sources.

Exotic plant invasions threaten ecological communities world-wide. Some species are limited by a lack of suitable pollinators, but the introduction of exotic pollinators can facilitate rapid spread. In Tasmania, where many non-native plants are naturalised, exotic honeybees (Apis mellifera) and bumblebees (Bombus terrestris) have become established. We determined how these species affect the pollination of Lupinus arboreus, an invasive, nitrogen-fixing shrub, which is rarely visited by native pollinators. The proportion of flowers setting seed and the number of ovules fertilised per flower were positively related to the visitation rates of both exotic bee species. There was no effect of bee visitation rates on the proportion of seeds aborted prior to maturity, possibly due to post-fertilisation fertilisation environmental constraints. We conclude that the spread of B. terrestris may not alter the fecundity of L. arboreus because of the pollination service provided by A. mellifera, and discuss potential interactions between these two bee species.

Africanized honey bees (AHBs) of Brazil and Mexico have proven to be tolerant to Varroa destructor mites. In contrast, European honey bees (EHBs: Apis mellifera carnica) at the same tropical study site are highly intolerant to these ectoparasites. A lower attractiveness of Varroa -tolerant AHB larvae has been hypothesised to be an important trait in reducing the susceptibitlity of AHBs to these mites. Thus, selection for EHB brood that is less attractive to mites is thought to be one possibility for limiting mite population growth and thus increase the tolerance of EHBs to the mite. In Ribeirao Preto, Brazil, European A. m. carnica bees and AHBs were tested with respect to their rate of brood infestation and brood attractiveness to Varroa mites. For the comparison of brood infestation rates, we introduced combs with pieces of EHB and AHB brood into honey bee colonies (18 repetitions). The relative infestation rate of EHB brood was significantly higher compared to AHB brood. The preference behaviour of single Varroa mites was tested in a laboratory bioassay where either living host stages were offered or host extracts were presented on dummies. By these tests we could confirm the preference of Varroa females for certain developmental host stages and for their corresponding extracts. In contrast to the within-colony results, Varroa mites in the laboratory bioassay showed a slight preference for AHB compared to EHB larvae. The gas chromatographic analysis revealed differences in the chemical spectrum of extracts obtained from different larvae. In accord with the results of the bioassays, we could detect stage -specific odour differences in larval cuticular compounds, including methyl esters and hydrocarbons that have been described as kairomones. None of these substances, however, revealed significant race-specific differences. Therefore, the quantity and composition of certain cuticular compounds seem to be responsible only for the recognition of a suitable host stage by Varroa females. The different infestation rates in the colonies, however, seem to be caused neither by race-specific differences in attractiveness of bee larvae nor by an extended attractive period of EHB larvae: both AHB and EHB larvae become attractive approximately 21 h before capping of the brood cell, and thus have the same window of time when they can be parasitised. Therefore differential Varroa-infestation rates are not related to larval attraction but probably are determined by other race-specific and colony-related factors.

Experiments on basic classical conditioning phenomena in adult and young Africanized honey bees (Apis mellifera L.) are described. Phenomena include conditioning to various stimuli, extinction (both unpaired and CS only), conditioned inhibition, color and odor discrimination. In addition to work on basic phenomena, experiments on practical applications of conditioning methodology are illustrated with studies demonstrating the effects of insecticides on learning and the reaction of bees to consumer products. Electron microscope photos are presented of Africanized workers, drones, and queen bees. Possible sub-species differences between Africanized and European bees are discussed.

Honeybees Apis mellifera can associate an originally neutral odor with a reinforcement of sucrose solution. Forward pairings of odor and reinforcement enable the odor to release the proboscis extension reflex in consecutive tests. Bees can also be conditioned differentially: They learn to respond to a reinforced odor and not to a nonreinforced one. They can also learn to reverse their choice. Here we ask whether honeybees can learn successive olfactory differential conditioning tasks involving different overlapping pairs of odors. The conditioning schedules were established in order to train the animals with 3, 2, 1, or 0 reversals previous to a last differential conditioning phase in which two additional reversals were present. We studied whether or not successive reversal learning is possible and whether or not learning olfactory discrimination reversals affects the solving of subsequent discrimination reversals. Therefore we compared the responses of bees that had experienced reversals with those of bees that had not experienced such reversals when both are confronted with a new reversal situation. In experiment 1 we showed that bees that had experienced three previous reversals were better in solving the final reversal task than bees with no previous reversal experience. In experiment 2, we showed that one reversal learning is enough for bees to perform better in the final reversal task. The successive different reversals trained in our experiments resemble the natural foraging situation in which a honeybee forager has to switch successively from an initial floral species to different ones. The fact that experiencing such changes seems to improve a bee's performance in dealing with further new exploited food sources has therefore an adaptive impact for the individual and for the colony as a whole.

In a field trial, significant increases for the total number of bolls harvested (11.1%), total mass of bolls (16.5%), total lint mass (15.8%), total seed mass (19.7%) and total number of seeds per sample (16.5%) were obtained from plots receiving the highest number of bee visits compared with plots receiving the lowest number of bee visits. Lint-quality examinations resulted in a significant improvement for micronaire and fineness with increased bee visits. Non-significant increases were obtained for the mass of 100 seeds (3.8%), average single seed weight (3.9%), average number of seeds per boll (4.7%) and average weight of lint per boll (5.0%). Caged plots with honey bees had significantly greater total boll mass; total seed mass; and average single-seed weight than caged plots without honey bees.

A new RT-PCR test was developed for the diagnosis of chronic bee paralysis virus (CBPV) infection. Used in parallel with an experimental infection test, the RT-PCR test was less fastidious and allowed the detection of latent CBPV infection in colonies. The new test is based on the fact that clinical CBPV infections (but not latent infections) yield a high viral antigen load that can be easily revealed using the agarose gel immunodiffusion (AGID) test. The combination of the AGID and the RT-PCR tests allowed us to characterise the CBPV status of hives from various apiaries in France as non infected, latently infected or clinically infected. The RT-PCR test proved highly sensitive for detecting inapparent infections. It may be a useful tool for studying the epidemiology of the disease.

Investigations at different sites in the southern parts of Mali (West Africa) revealed the presence of 26 species of Apoidea, 3 of Pompilidae and 10 of Vespidae. Most of the specimens were collected near human settlements. Watering places and gardens showed a high attraction to bees and wasps during the dry season. Until now, only Apis mellifera ssp. adansonii and Anthidium (Icteranthidium) ferrugineum ssp. discoidale were recorded in Mali. Apis mellifera ssp. adansonii is threatened by human activities. But man-made environmental changes seem to produce effects on the composition of many other aculeate Hymenoptera.

Efficacy of Trichoderma spp. to reduce sunflower head rot caused by Sclerotinia sclerotiorum was evaluated in the field. A mixture of six isolates, including Trichoderma koningii, T. aureoviride and T. longibrachiatum, was tested in five field trials at Balcarce, Argentina. Trichoderma formulation (TF) included Trichoderma conidia and viable hyphal fragments, industrial talc and milled corn kernels. Honeybees (Apis mellifera) were used to disperse TF for six weeks from the onset of flowering. Two days after the first TF delivery, sunflower heads were inoculated with S. sclerotiorum ascospores. When 100 g TF was taken by honeybees in a 10-h per day period, head rot incidence was significantly reduced. This approach was successful in reducing disease incidence until physiological maturity of the crop, in environments highly conducive to head-rot development.

Although severe reactions to the sting of the common honey bee (Apis mellifera) are a common problem in Australia, reported deaths are uncommon, with the estimated mortality varying from one to four persons each year. The following study presents the postmortem findings in three cases of bee sting fatality, including one in which no observable sting was found. An autopsy approach to such cases is detailed. Over-reporting of bee sting-related deaths may occur due to the inclusion of deaths unrelated to a reaction to bee venom, while under-reporting may be due to unexplained deaths where a history of a bee sting is not available or apparent at autopsy. A classification of bee sting-related deaths is proposed, which would allow more accurate reporting of bee sting-related fatalies. A serum tryptase and specific IgE to bee venom on serum obtained at autopsy can assist in confirming anaphylactic reaction to bee venom as the cause of death, particularly in the absence of observable stings. Although there are limitations to the usefulness of serum tryptase tests in the postmortem situation, it may still be useful to confirm suspected anaphylaxis in autopsy cases with an undetermined cause of death.

In the honey bee, it is difficult to recognise the sex in first instar larvae. As workers and haploid drones develop in differently sized brood cells, they can be discriminated without sex inspection. However, because diploid drone larvae originate from fertilised eggs like workers, they hatch in brood cells of the same type and cannot be sampled according to cell size. In search of a reliable method of sexing live first instar larvae, we found that the contour and size proportions of the epiproct can be used for discrimination. The sex diagnosis based on these characters is carried out rapidly under a stereo microscope and allows the collection of pure samples of newly hatched diploid drone larvae from brood combs of inbred colonies.

This study investigated the impact of Varroa destructor infestation on the amount of capped worker brood, the adult bee population and honey production of authenticated Apis mellifera carnica colonies kept in a Mediterranean climate. For this purpose, colonies were set-up and either maintained mite-free or artificially mite-infested and allowed to develop an infestation. Periodical evaluations of those colonies unravelled the pattern of the previously mentioned variables across the season, and allowed for comparative numerical analyses. Progressive reductions on the amount of capped worker brood, bee population and honey storage in mite -infested colonies only became increasingly evident during spring and summer, apparently associated with impressive mite population increases. By the end of the experiment, mite-infested colonies showed a unitary average reduction of 45% in the amount of capped honey they stored, meaning an average annual loss of apprxeq 24 kg of honey per colony. However, the amount of capped honey stored per bee and day was found to be independent from colony V. destructor status, indicating a lack of direct effect of mite infestation on honey hoarding behaviour.

beta-glucosidase has been purified from the ventriculus and honey sac of Apis mellifera using a combination of anion- and cation-exchange, hydroxyapatite and gel-permeation chromatography. In addition, beta -glucosidase from the hypopharyngeal glands has been partially purified using anion-exchange and gel-permeation chromatography. The purified beta -glucosidase gave a positive result by glycoprotein staining. This beta -glucosidase consists of only one subunit and has Mr of 72 kDa as determined by SDS-PAGE. IEF-PAGE showed several bands with pIs ranging from 4.5 to 4.8. These multiform proteins have been proposed as having different degrees of glycosylation. The pH optimum of the purified beta -glucosidase from the ventriculus and honey sac are 5.0. These enzymes were stable at temperatures up to 50 degreeC and have a relatively wide pH stability range of 4.0 to 9.0. MALDI-TOF-MS peptide mass maps of purified beta-glucosidase from the ventriculus, honey sac and hypopharyngeal glands showed six matching masses. These results indicate that the beta -glucosidase isolated from the hypopharyngeal glands, honey sac and ventriculus is the same. It is proposed that beta-glucosidase is produced in the hypopharyngeal glands, secreted into the mouth during feeding and then passes to the honey sac. From the honey sac, this enzyme is transferred into honeycomb cells and the ventriculus.

In this study the efficiency of bee traps used to evaluate mortality in a bee colony and their influence on undertaking behaviour was tested in twelve colonies of Apis mellifera L. Four types of bee traps (Original -Gary-Trap, a Modified-Gary-Trap, the IPSAB-Trap and the Muenster-Trap), commonly used in practical research, were compared to each other and to control colonies without a trap. The use of different bee traps led to incomparable results. In the Original-Gary-Trap, many stray bees were trapped and eventually died within the glass collecting jars, leading to artificially high estimates of mortality. Bees removed the dead bees from the Modified-Gary-Trap, especially during good flight conditions. Dead bees disappeared from the IPSAB-Trap because of predators and wind. Both Gary-Traps had a negative effect on undertaking behaviour; the number of behavioural components involved in removing a dead bee from the colony was large and thus, undertaking took a long time. In IPSAB-Trap, the undertaker bees showed the same number of behavioural components and took similar times to remove dead bees as the control colonies without traps. The newly developed Muenster-Trap, equipped with an easily accessible hive entrance, a collecting box for dead bees and an outlet for stray bees, gave a significantly improved performance.

The number and distribution of the various types of antennal sensilla of queens, half-queens and workers of Apis mellifera lamarckii were examined. Sensilla placodea (SP), sensilla ampullacea (SA), sensilla coeloconica (SC), sensilla campaniformia (SCF), sensilla basiconica (SB) and sensilla trichodea (ST) (types A, B1+B2 and C+D) were observed on flagella of the three female types of bee. Queens and half-queens had similar numbers of most types of sensilla; queens had fewer SC and more ST types C+D. The numbers of SCF and SC varied most among bee types. The total number of ST type B, ST type A and SB showed greatest weights in discrimination analysis of the three types of flagella. Three well-separated groups representing the three types of flagella were obtained by using discriminant analysis.

The Copey tree (Clusia rosea) has a large distribution in Cuba and its floral resin is a rich source of polyisoprenylated benzophenones. To determine the presence of these natural products, we carried out a study by HPLC of 21 propolis samples produced by honey bees (Apis mellifera) from different provinces of Cuba. Nemorosone resulted to be the most abundant polyisoprenylated benzophenone and the mixture of xanthochymol and guttiferone E was also observed, but in minor proportion. We studied the biological activity of the pure natural product nemorosone and its methyl derivatives. We found that nemorosone has cytotoxic activity against epitheloid carcinoma (HeLa), epidermoid carcinoma (Hep-2), prostate cancer (PC-3) and central nervous system cancer (U251). It also exhibited antioxidant capacity. Methylated nemorosone exhibited less biological activity than the natural product.

Hygienic behaviour of the carniolan honeybee (Apis mellifera carnica Pollm.) was investigated in 20 localities in Serbia (10 localities from the Machva region and 10 localities from the Rudnik region). The results revealed that the grey bees from Rudnik have a more expressed form of hygienic behavior, compared to the yellow bees from Machva. The obtained data indicate that colonies of both investigated honeybee varieties, yellow bees from Machva and grey bees from Rudnik, belong to a category of the so called "hygienic colonies", as the efficiency of elimination of damaged pupae amounted to 91.45% in Machva honeybees and 93.60% in Rudnik honeybees. Our results point to an indisputable relationship between hygienic behaviour and the strength of honeybee colonies, i.e. the potent colonies have more expressed hygienic behaviour. Both investigated honeybee varieties can be used for improving breeds selection and for organic beekeeping in Serbia, owing to the manifested hygienic behaviour and thence, resistance to some diseases (Varroa, American foulbrood, and especially Chalkbrood).

Varroa destructor Anderson and Trueman females were placed in contact with queen; worker, and drone brood cells of Apis mellifera L. that were soon to be sealed. In a non-choice test, V. destructor adult females were introduced into a comb containing either queen or worker brood cells; 0.62 and 18.28% of the mites entered the queen and worker brood cells, respectively. Only 1 of the 11 mites that entered queen brood cells oviposited, laying a single egg. In another test, brood cells were combined in the same comb in a 1:25:3 queen:worker:drone ratio. The percentages of egg-laying mites in queen, worker, and drone brood cells were 16.66, 61.86, and 79.06%, respectively. When queen, worker, and drone brood cells were combined in equal proportions (33.3:33.3:33.3), percent infestation was significantly different among queen (3.25%), worker (49.12%), and drone (90.07%) brood. Multiple infestation was found in drone brood cells but not in others. Also, mites were inoculated into sealed queen cells. These cells contained either one or two mites (either at the egg or protonymph stage). Conversely, in a simultaneous test with worker brood cells, the offspring per foundress mite included a mean of three individuals (either at the egg, protonymph, or deutonymph stage). It is concluded that V. destructor can infest queen, worker, and drone brood cells, but drone brood cells are preferred; in addition, queen brood cells do not provide an optimal environment for reproduction because it causes a delay in mite oviposition and (or) progeny development.

Honey bee (Apis mellifera) colonies exhibiting clinical symptoms of American foulbrood (AFB, causative agent Paenibacillus larvae larvae) were divided into 2 groups that received different shaking treatments: (1), shaking adult bees into a new hive; and (2), shaking adult bees in front of the entrance to a new hive. Honey bee and honey samples were taken before shaking and 1, 22, 44 and 66 days after shaking. Microbiological cultures were made from honey and honey bee samples to determine P. I. larvae development. The average number of P. I. larvae cfu/g honey before shaking was 89.86 +- 17.93 (x +- s.e.) and more than 500 cfu/bee for honey bee samples. Honey bee samples had more colony-forming units before shaking but differences were not statistically significant after shaking. An important reduction in the number of colony-forming units in honey bee and honey samples was detected after shaking by both methods and no significant difference was detected between them. Honey and honey bee samples were positive for the presence of P. I. larvae in every sampling but no AFB clinical symptoms were detected in the honey bee colonies after 5 months. These results allow us to conclude that both shaking methods reduce spore loads in new colonies without using chemicals and, using them with other management procedures would allow development of an integrated AFB control method.

This experiment was conducted in northern Badia, Jordan, during 1997 and 1998, to investigate the feasibility of beekeeping in this arid region. 12 colonies of Apis mellifera syriaca were used. Half of the colonies remained in Badia during the experimental period (stationary hives), the rest were transported between the study area and the Jordan Valley (migratory hives). Results showed that colonies began their brood rearing activity in Badia during the early stages of the nectar flow and pollen yield in January, but it dropped almost to zero at the end of August. The peaks of brood rearing occurred during March and June. Maximum adult populations for the entire season were found during April and July, dropping to a minimum for the year in December. Behaviour of migratory colonies was very similar to that of the stationary colonies. Seasonal brood rearing activity and population of adult bees in both treatment groups showed the same general trend in the second year. Annual average honey production was estimated to be 10 kg per colony for stationary hives and 6 kg per colony for migratory hives.

We identified a novel gene, Ks-1, which is expressed preferentially in the small-type Kenyon cells of the honeybee brain. This gene is also expressed in some of the large soma neurons in the brain and in the suboesophageal ganglion. Reverse transcription-polymerase chain reaction experiments indicated that Ks-1 transcripts are enriched in the honeybee brain. cDNA cloning revealed that the consensus Ks-1 cDNA is over 17 kbp and contains no significant open reading frames. Furthermore, fluorescent in situ hybridization revealed that Ks-1 transcripts are located in the nuclei of the neural cells, accumulating in some scattered spots. These findings demonstrate that Ks-1 encodes a novel class of noncoding nuclear RNA and is possibly involved in the regulation of neural functions.

The history of the classification of Apis mellifera capensis is traced. The distributions of the traits thelytoky, ovariole number and spermatheca size of workers are given. Thelytoky in workers extends over 240 000 km2 and the ratio of female/male progeny in laying worker offspring is clinal. Ovariole numbers are also clinal but spermatheca size is not. Allozymically, southern African honeybees are homogeneous; but differ in mtDNA haplotypes and nuclear DNA diversity. Morphometric analyses yield three distinct morphoclusters (A. m. capensis, A. m. scutellata, and unnamed mountain bees). Conventional morphometric classification is incongruous with the mode of parthenogenesis and distribution of mtDNA and nuclear DNA diversity in the honeybees of southern Africa. The terms "A. m. capensis" and "A. m. scutellata" are only meaningful if the precise geographical origins of the bees are specified.

Thelytokous Apis mellifera capensis workers recently brought into regions occupied by the arrkenotokous African bee A. m. scutellata, parasitise these colonies, causing colony death. These capensis workers are genetically almost identical and are referred to as a 'pseudo-clone'. We surveyed 120 scutellata colonies, 27 in detail, at various stages of usurpation by the pseudo-clone. The scutellata queen could co-exist with egg-laying pseudo-clones for 50+ days in one case but disappeared 1-15 days in three other cases. Despite the presence of emerged queen cells no new adult queens of either race were observed in usurped colonies. Only 11+-13% of the pseudo-clone population had fully active ovaries, suggesting ovarian development is inhibited in the majority of the pseudo -clones. Only 2.7+-1.7% of the foraging force were pseudo-clones. The data were modelled and showed the rapid (56-105 days) growth of the pseudo -clone population and colony death over a wide range of initial conditions.

Queen mandibular, tergal, tarsal and Dufour's gland secretions, as well as brood pheromones regulate worker reproduction in honeybees. In South Africa two contiguous populations of honeybees exist, Apis mellifera capensis and A. m. scutellata. Queenless A. m. capensis workers are reproductively distinct from workers of other races, in that they readily develop into pseudoqueens with rapid ovary and signal development. A. m. capensis queens are pheromonally competent in regulating reproduction in the resident workers. Recently however Cape honeybee workers have successfully invaded queenright A. m. scutellata colonies and simultaneously escaped reproductive suppression from the resident queen and brood. These "social parasites" rapidly develop into reproductives, lay acceptable eggs and mimic a series of queen pheromones. This pheromone mimicry by invading A. m. capensis workers causes a breakdown in reproductive regulation, resulting in reproductive anarchy.

Thelytokous parthenogenesis in Cape worker honeybees, Apis mellifera capensis, was used to produce a series of clonal progeny that were reared in three different, queenless arrhenotokous A. m. scutellata host colonies. Each individual Cape worker bee was genotyped at 4 DNA microsatellite loci to verify its clonal status and measured for 36 morphological characters. The clonal workers bees, all of the same thelytokous matriline, were then analysed by multivariate analysis to determine the quantitative effects of environment on the morphological characters. This in turn allows the estimation of the natural variation in the phenotypic expression of morphological characters. Coefficients of environmental variation were calculated and the relative stability of the character set was, in decreasing order, body size, forewings, wing venation, hairs and pigmentation.

A population ecological host- parasite model is used to evaluate the potential impact of clonal parasitic laying workers of the Cape honeybee, Apis mellifera capensis on populations of Apis mellifera scutellata host colonies in apiaries and in the wild. The model includes three basic life history parameters: reproductive rate of the host colonies, transmission efficiency of the parasite and the death rate of parasitised colonies. The population dynamics of host and parasites are computed for 100 generations after an initial infestation with parasitic workers. The model reveals that infestations are likely to be fatal for apiary populations irrespective of beekeeping activities compensating for colony losses due to parasitation. Wild A. m. scutellata populations are however less likely to be affected by parasitic laying workers and stable equilibria between host and parasite occur over a wide range of the parameter space. Although it is unlikely that the parasitic clone represents a threat to the conservation of biodiversity, even low frequencies of parasitic A. m. capensis workers in wild honeybee population can cause a permanent threat to beekeeping activities.

Queenright Apis mellifera capensis colonies exhibit egg laying by workers in periods of both low and high egg removal. To reproduce workers should lay in times of low egg removal to increase survival of their eggs. Were this so, a negative correlation between egg laying and removal would be expected. Egg removal rates for queen (N=240) and worker-laid (N=240) eggs and egg laying by workers were tested in queenright colonies. Worker-laid eggs were removed significantly faster than queen-laid eggs; but significant differences in egg laying by workers occurred among colonies. Egg laying and removal are positively correlated and co-dependent. Egg removal appears triggered by the number of worker-laid eggs. Intercolonial variation for laying worker egg number and egg removal rates may explain the phenotypic variation in worker reproduction in queenright Cape honeybee colonies.

Besides activation of ovaries and thelytokous reproduction of Cape workers, larval nutrition is an important aspect in parasitism of the African honey bee. When reared by workers of other subspecies, Cape larvae receive more food which is slightly more royal jelly-like. This results in worker-queen intermediates, with reduced pollen combs, enlarged spermathecae and higher numbers of ovarioles. The intermediates weigh more and develop faster than normal workers. The appearance of worker-queen intermediates probably affects parasitism of the African honey bee colonies by Cape workers. Different levels of larval nutrition resulting in less distinct caste differentiation may be important for the reproductive success of Cape workers in their own colonies. Similar processes, albeit less pronounced, may occur in colonies of other subspecies.

Two lines of honey bees (Apis mellifera ligustica) were selectively propagated by instrumental insemination using the population growth of the Varroa mite as a criteria. Different infestation rates are at least partially genetic since selection produced significant bi-directional differences between lines over a period of three subsequent generations. There was no correlation between several behavioural and physiological characteristics which are potentially associated with Varroa resistance (hygienic behaviour, physical damage to mites, infertility of the intruding mites) and the development of the Varroa population after artificial infestation. There was a positive significant correlation between the total mites in the colonies and the amount of reared brood. Colony infestation was also positively correlated with the amount of honey harvested.

Illegal harvesting is a serious threat to the persistence of many plant and animal taxa. The combination of highly polymorphic DNA markers and new statistical methods called "assignment tests" can potentially help detect and thereby reduce poaching. Assignment tests can identify the population of origin of individuals if populations are genetically differentiated. We evaluated the usefulness of two assignment tests to wildlife forensics by applying them to large empirical (microsatellite DNA) data sets from 10 species. We also conducted computer simulations to assess the influence of genetic polymorphism (heterozygosity) and population differentiation (FST) on the performance of the tests. The fully Bayesian assignment test of Pritchard et al. (2000) performed better than the partially Bayesian exclusion test of Cornuet et al. (1999), but the fully Bayesian method requires the assumption that the true population of origin was sampled. The median percentage of individuals correctly assigned for the 10 empirical data sets was 61% and 36% for the assignment and exclusion tests, respectively. Both the empirical and simulated data sets suggest that nearly all individuals can be assigned with high statistical certainty (99.9%) for two highly differentiated populations (FST apprxeq 0.15-0.2) when 10 loci (H RGT 0.6) and samples of 30-50 individuals are used per population. We recommend using both tests when the true population of origin might not have been sampled in the data set.

The stinging and guarding components of the defensive behavior of European, Africanized, hybrid, and backcross honeybees (Apis mellifera L.) were compared and analyzed at both colony and individual levels. Hybrid and Africanized backcross colonies stung as many times as Africanized ones. European backcross colonies stung more than European bees but not as many times as Africanized or Africanized backcross colonies. The degree of dominance for the number of times that worker bees stung a leather patch was estimated to be 84.3%, 200.8%, and 145.8% for hybrid, backcross European, and backcross Africanized colonies, respectively. Additionally, both guards at the colony entrance and fast-stinging workers of one European backcross colony had a significantly higher frequency of an Africanized DNA marker allele, located near "sting1," a QTL previously implicated in stinging behavior at the colony level. However, guards and fast-stinging bees from a backcross to the Africanized parental colony did not differ from control bees in their frequency for the Africanized and European markers, as would be expected if large genetic dominance effects for sting1 exist. These results support the hypothesis that genetic dominance influences the defensive behavior or honeybees and confirm the effect of sting1 on the defensiveness of individual worker bees.

Cape honeybee workers show important pre-adaptations for social parasitism and can cause the dwindling colony syndrome of host colonies. Parasitic workers may drift or actively disperse into host colonies. They may also join absconding swarms, which can merge with host colonies. After transmission, parasitic workers have to establish themselves in the host, which is probably promoted by their spatial distribution, their readiness to gain trophallactic dominance and their ability to survive worker-worker aggression. Established parasitic workers have to evade egg removal by other workers in host colonies. The resulting offspring is preferentially fed, can be expected to be highly virulent and may show different behaviour in the course of infestation. It is unknown why and how the host queen is lost. High numbers of parasitic workers are reared until the host colony dies or absconds. This offspring can infest new host colonies, thereby completing the social parasitic life cycle.

Honeybees (Apis mellifera) use odors to identify and discriminate among flowers during foraging. This series of experiments examined the ability of bees to detect and discriminate among the floral odors of different varieties of two species of canola (Brassica rapa and Brassica napus) and also among three varieties of snapdragons (Antirhinnum majus). Individual worker honeybees were trained using a proboscis extension assay. The ability of bees to distinguish a floral odor from an air stimulus during training increased as the number of flowers used during training increased. Bees conditioned to the odor of one variety of flower were asked to discriminate it from the odors of other flowers in two different training assays. Bees were unable to discriminate among flowers at the level of variety in a randomized presentation of a reinforced floral odor and an unreinforced floral odor. In the second type of assay, bees were trained with one floral variety for 40 trials without reinforcement and then tested with the same variety or with other varieties and species. If a bee had been trained with a variety of canola, it was unable to differentiate the odor of one canola flower from the odor of other canola flowers, but it could differentiate canola from the odor of a snapdragon flower. Bees trained with the odor of snapdragon flowers readily differentiated the odor of one variety of a snapdragon from the odor of other varieties of snapdragons and also canola flowers. Our study suggests that both intensity and odor quality affect the ability of honeybees to differentiate among floral perfumes.

The number of Apis mellifera foragers peaked between 0930 h and 1130 h at the beginning of buckwheat's blooming season and when buckwheat was in full bloom. However, the highest number of foragers occurred between 0830 h and 1030 h during the late blooming period. Most A. cerana foragers appeared before 0930 h with numbers starting decline after 1030 h at each stage of the blooming season of buckwheat. The number of honeybee foragers on BeelineR- sprayed buckwheat plots did not show significant difference from the control plot. The total number of grains per buckwheat plant from the BeelineR- sprayed plots was significantly higher than that of control plot, but the weight of 1000 grains did not differ. A. mellifera foraged the rape before 1130 h, similar to the buckwheat. Most A. mellifera foragers on pear flowers were found within 50 m of the beehive, but not more than 150 m. A. cerana foragers were not found more than 100 m from the beehive. A. mellifera foraged pear flowers mainly for pollen. The percentages of pollen foragers in two tested orchards were 54% and 46%, which are respectively 1.4 and 2.7 fold the percentages of the nectar foragers. On the contrary, A. cerana foraged mainly for nectar and the population of nectar foragers were two and three folds larger than those of the pollen foragers. The main pollen-foraging activity of A. mellifera occurred between 1100 h and 1500 h, but the nectar-foraging activity occurred at 1300 h. The nectar-foraging activity of A. cerana mostly occurred between 1500 h and 1700 h. When the grafted scions of Hosui and Kosui varieties were opened to honeybee pollination, the percentages of fruit setting were 46% and 78%, respectively, and each scion could bear an average of 2.2 pears. Hand pollination resulted in 50% fruit setting and 1 -2 pears on each scion. When the A. mellifera colonies were placed in a pear surrounded orchard the mean daily number of dead workers (86) was 6 times that of the colonies placed in a relatively isolated orchard. But, there were no differences in the number of dead workers of A. cerana, with daily numbers of dead workers between 9 and 10.

Nucleotide sequence analyses were used to identify acute bee paralysis virus (ABPV) and Kashmir bee virus (KBV) isolated from a single honey bee colony. Most of the bees in this colony carried KBV. Some individual bees also carried ABPV, a coexistence not yet seen between these two viruses. Implications of coinfection on viral efficacy are discussed, along with a restriction enzyme assay that can be used to discriminate between these two widespread viruses.

The morphology of the cyst cells in Apis mellifera Linne, 1758, Scaptotrigona postica Latreille, 1804, and Melipona bicolor bicolor Lepeletier, 1836 testis, as well as the average number of spermatic cells are reported. The data indicates a supporting and nourrishing role of the cyst cells to the developing cystocytes. The counts of immature spermatozoa in the cysts show an average of 202.8+-21.2 spermatozoa for A. mellifera, 117.4+-8.68 for S. postica and 88.8+-15.57 for M. bicolor, which predict the occurrence of 8 mitotic cycles in the cystocytes of A. mellifera and 7 in the meliponines, considering that only one spermatozoom originates of each final spermatogonium.

To accelerate the molecular analysis of behavior in the honey bee (Apis mellifera), we created expressed sequence tag (EST) and cDNA microarray resources for the bee brain. Over 20,000 cDNA clones were partially sequenced from a normalized (and subsequently subtracted) library generated from adult A. mellifera brains. These sequences were processed to identify 15,311 high-quality ESTs representing 8912 putative transcripts. Putative transcripts were functionally annotated (using the Gene Ontology classification system) based on matching gene sequences in Drosophila melanogaster. The brain ESTs represent a broad range of molecular functions and biological processes, with neurobiological classifications particularly well represented. Roughly half of Drosophila genes currently implicated in synaptic transmission and/or behavior are represented in the Apis EST set. Of Apis sequences with open reading frames of at least 450 bp, 24% are highly diverged with no matches to known protein sequences. Additionally, over 100 Apis transcript sequences conserved with other organisms appear to have been lost from the Drosophila genome. DNA microarrays were fabricated with over 7000 EST cDNA clones putatively representing different transcripts. Using probe derived from single bee brain mRNA, microarrays detected gene expression for 90% of Apis cDNAs two standard deviations greater than exogenous control cDNAs.

The infamous African honeybee Apis mellifera scutellata of South Africa is now under threat from a parasite from its own species. Since 1990, a clone of A.m. capensis workers has been invading colonies of A.m. scutellata and parasitizing brood with their eggs, causing the host A.m. scutellata to raise yet more parasitizing workers. A new study by Martin et al. now shows how the A.m. capensis workers subvert the mechanisms that normally prevent worker reproduction.

We observed the nursing of larvae during all 5 days of larval development. We caged a queen in a specific area of empty combs inside the broodnest and filmed nursing episodes within this area. We created 5-day observations periods with and without artificial rain, as well as periods with and without manual reduction of pollen stores and reduction of pollen income. In rain periods, there were significantly fewer nursing episodes for young larvae (1-3 days old) than in no-rain periods. The nursing frequency was significantly correlated with the amount of pollen in the hive, as well as with the total amount of unsealed larvae. The ratio of available pollen to larvae had the strongest influence on the nursing frequency: the more pollen available per larva, the higher the nursing frequency of young larvae. Higher nursing frequency, as well as a longer total duration of nursing episodes, resulted in a higher protein content of the larvae. In contrast, the frequency of nursing of older larvae (4 days old) did not depend on the amount of pollen or on the ratio of pollen to larvae, even after some days of severe pollen reduction. The amount of honey stores and the weight of the hive were not correlated with the nursing frequency of any larval age group. When pollen becomes scarce, older larvae receive preferential treatment. They represent a considerable investment for the colony. From an economic point of view, it is important for the colony that they reach the "safe" final capping stage.

In seeking genetic factors that may control the extended behavioural maturation of adult honeybees we found that inositol 1,4,5-trisphosphate (IP3) 3-kinase, a key enzyme in the IP3-mediated signalling cascade, is differentially expressed in brains of naive, newly emerged bees and experienced foragers. DNA sequencing yielded a contig of 21.5 kb spanning the honeybee IP3K locus and a 3' flanking gene similar to a transcription factor NFR-kappa-B. The IP3K locus gives rise to three differentially expressed major transcripts produced by alternative splicing that encode proteins with identical, highly conserved C-termini and distinct, non -conserved N-terminal domains. The type A transcript is dominant in the adult brain and its level of expression increases threefold during the first 4 days of adult development. The type B message is expressed in brains of naive bees, but is also found in the thorax and abdomen, whereas transcript C is expressed largely in non-neural tissues and in the antenna. In contrast to type A message, the brain levels of transcript B decrease during the first 4 days of adult life. Our data are evaluated in the context of the contrasting behavioural phenotypes of immature and experienced worker honeybees.

A worker-queen contact in the retinue of the honeybee (Apis mellifera) enables transfer of queen pheromones to workers. Behaviours of workers attending the queen and post-contact behaviours were recorded. The most commonly observed activities of workers in retinue were licking and antennating the queen. Those activities were interrupted with bouts of self-grooming, which was the most frequently observed activity of licking attendants. Immediately after leaving, the queen workers which had licked the queen, self-groomed longer and more frequently than workers which had antennated the queen. Licking post-retinue workers walked significantly faster and rested less frequently than palpating post-retinue workers, which suggest that licking attendants are most effective in the pheromone transfer accomplished by accidental encounters with other nestmates.

In an apiary composed of 14 hygienic and 7 non-hygienic colonies of Apis mellifera Linnaeus, 1758 the presence of visible and capped mummies was recorded, one hygienic and 4 non-hygienic colonies showed symptoms of chalkbrood. Twenty-eight days after a massive contamination of the colonies with pollen patties containing Ascosphaera apis Olive AMPERSAND Spiltoir, 1955, the situation was almost identical to that at the beginning: the same 4 non-hygienic colonies still were infected and one hygienic colony that was healthy became infected. The high proportion of hygienic colonies that eliminated the disease symptoms suggests that they could maintain themselves healthy in spite of the presence of colonies with chalkbrood in the apiary.

Through the use of proboscis-extension reflex conditioning, we demonstrate that honey bees (Apis mellifera L.) bred for hygienic behavior (a behavioral mechanism of disease resistance) are able to discriminate between odors of healthy and diseased brood at a lower stimulus level than bees from a non-hygienic line. Electroantennogram recordings confirmed that hygienic bees exhibit increased olfactory sensitivity to low concentrations of the odor of chalkbrood infected pupae (a fungal disease caused by Ascosphaera apis). Three-week-old hygienic bees were able to discriminate between the brood odors significantly better than three-week old non-hygienic bees. However, the differential performance in brood odor discrimination was primarily genetically based, not a direct result of age, experience, or the temporary behavioral state of the bee. Lower stimulus thresholds for both the olfactory and behavioral responses of hygienic bees may facilitate their ability to detect, uncap and remove diseased brood rapidly from the nest. In contrast, non-hygienic bees, possessing higher response thresholds, may not be able to detect diseased brood as easily. Our results provide an example of how physiological and behavioral differences between the hygienic and non-hygienic honey bee lines, operating at the level of the individual, could produce colony -specific behavioral phenotypes.

Epidemics of plant diseases in Egypt represent a problem that we haven't sufficient data to face their effect on crop yield. Fire blight caused by Eriwina amylovora (Burrill) Winslow et al., is one of the most destructive diseases of apples and pears worldwide. The present investigation was planned to study factors affecting growth of E. amylovora and disease development, in vitro, and relationship between environmental conditions and population of E. amylovora in different pear tissues and disease incidence. Also, the role of some insects i.e. Bee (Apis mellifera) and wood minors (Zeuzera pryina) in disease transmission was studied. The growth of E. amylovora in vitro was at its maximum rate at temperature degree ranged from 20degree to 30degree, 90-100% RH and pH values of 6.6 -7.4, similar data concerning the amount of bacterial ooze released from artificially inoculated pear fruits as well as the percentage of infected slices, under laboratory conditions, where maximum ooze production was recorded at the same environmental factors. High population of E. amylovora was found in cankers. Also, percentage of samples showing E. amylovora was relatively high in carikers and moderate in flowers. A definite relationship was observed between spring and autumn temperatures and population of E. amylovora and occurrence of fire blight of pear at field. Initial infection was noticed from March 28th up to April 6th, where average temperature degrees ranged from 20.3degree to 21.4degree, there was a direct relationship between certain insects and incidence of fire blight disease. It was evident that bee was active disseminator of E. amylovora and wood minors have a moderate effect in transmission.

Chalkbrood disease in Apis mellifera is a fungal disease affecting developing brood, infested larvae become mummified. As it is a factorial disease, studies on this pathology are obstructed by the need of some predisposing conditions which must occur for such disease to develop. Thus, many questions are yet to be answered about which treatments to apply. The aim of this work is to evaluate the efficacy of the Apimicos -B(R), a treatment against chalk brood. To induce the disease, some pieces of combs containing susceptible worker brood both from infected and treated colonies and from infected and untreated colonies were cooled. No significant differences were registered (53.12% and 59.58% of mummification respectively).

This study examined the migration of tracheal mites (Acarapis woodi) into honey bees (Apis mellifera) from different colonies and the relative attraction of mites to hexane extracts from the external body surfaces of young bees. Relative resistance of bees from different colonies initially was assessed with a field bioassay that involved tagging newly emerged bees, pooling them in heavily mite-infested colonies, retrieving them 7 days later, and examining them for tracheal mite prevalence and abundance. For those colonies identified as most resistant and least resistant, cuticular chemicals were extracted in hexane from frozen, newly emerged worker bees. These extracts were presented to individual tracheal mites in pairwise fashion in a laboratory bioassay. The results demonstrated that mites prefer extracts of bees from some colonies more than others, however, no consistent differences were demonstrated. Our inability to predict mite responses to extracts based on our initial assessment of relative resistance indicates that other mechanisms of resistance influence mite success in colonizing new host bees.

Wet weight, dry weight and water contents of emerging honeybees (Apis mellifera L. (Hymenoptera: Apidae)) infested with the ectoparasitic mite Varroa destructor (Anderson) (Acari: Varroidae) were all negatively correlated with increasing numbers of mites. It was estimated that for every female mite present during the bees' development, the host would lose three percent of its body water. Parasitised bees also emerged with lower head and abdomen concentrations of protein and with lower abdominal carbohydrate concentrations. Lipid concentrations were not detectably affected by V. destructor infestation. The losses of metabolic reserves were not, however, judged to be serious enough to be directly responsible for the high bee mortality and ultimate colony collapse that are associated with the arrival of Varroa in a hive. Some 8.5% of the emerging bees exhibited morphological deformities and deformity was positively correlated with increasing numbers of mites in brood cells. Deformed bees were, however, found in all categories of parasitosis, suggesting that other factors, such as infectious agents, may be involved. Mites that fed on either live or dead U14C-labelled bees acquired the label within 24 h and it was calculated that an adult female mite consumes 0.67 mul haemolymph 24 h-1. It was also demonstrated that 14C was transmitted to a previously non-radio-labelled bee when a mite that had been feeding on a labelled bee changed hosts. The level of transfer was above that which could have arisen through contamination of the mites' mouthparts and supports the suggestion that Varroa is an important vector of pathogens such as viruses.

In the present studies, the colonies of Apis mellifera having high, medium and low brood survival showed significant variations in the bee population only during spring and not during summer and autumn. The low brood survival colonies also had significantly less brood in the spring season as compared to the normal colonies. During spring, the empty cells in the brood comb were 20.62 per cent in the colonies of low brood survival group as compared to the 9.47 per cent in high brood survival colonies. Maximum empty cells were found in all the colonies during autumn season.

Studies were conducted on abundance and foraging behaviour of insect pollinators of raya crop and role of Apis mellifera in its pollination at Ludhiana during 1989-90. Apis dorsata Fab., A. mellifera L., A. florea Fab. and Andrena sp. consitituted 51.43, 23.77, 20 and 4.80 per cent of total bees caught on this crop. Apis dorsata was more active between 10-16 h while A. mellifera and A. florea were active between 11-16 h. On an average, A. mellifera, A. dorsata, and A. florea visited 14.06, 11.36 and 5.81 flowers/minute. One, two and five bee visits/flower by A. mellifera resulted in 65.5, 82.5 and 88.4 per cent pod setting. Intensive pollination of raya by A. mellifera increased the number of seeds/pod by 12.22 per cent, seed germination by 7.15 per cent and oil content by 8.31 per cent over natural pollination. When the visit of A. mellifera was excluded from the flowers, it resulted in decrease of these parameters by 13.57, 0.23 and 2.39 per cent respectively.

Individually labeled newly emerged honeybee workers were introduced into three queenright host colonies. The host colonies were housed in observation hives with one brood frame. The location of the workers during their first eleven days of life was monitored. In the initial phase of the experiment, the queen was allowed to roam freely in the colony. In a second phase of the experiment the queen was caged on one side of the frame. In all three colonies workers were observed either being attracted to or avoiding the queen. The mandibular gland secretions of workers attracted to the queen more often had the typical worker like mandibular gland secretion whereas workers avoiding the queen, produced a mandibular gland secretion more similar to that of a queen. This suggests that the workers avoiding the queen are attempting to escape queen control which otherwise suppresses the secretion of queen like pheromones.

Honey bees (Apis mellifera L.) reproduce by swarming wherein the mother queen leaves the nest with approximately two thirds of her workers (the prime swarm). Several daughter queens are raised in the original nest, and these start to emerge shortly after the first swarm departs. One or several of these daughter queens may then leave the original colony sequentially with smaller afterswarms. Here we study the change in acceptance of former nestmates after colony reproduction using free-flying honey bee colonies. We used a total of four colonies each of which we divided to make four new colonies: two artificial swarms (the offspring colonies) and two colonies that mimic established ('old') colonies after swarming. The way the original (mother) colonies were divided allowed us to determine the relative importance of wax comb on cue divergence. Half of the divisions contained the original wax combs from the mother colony whereas the other divisions were not provided with comb requiring them to construct their own. We then tested the acceptance of former nestmates by introducing foragers at the hive entrances and observing the behaviour of guard bees. Our results did not show a consistent change in acceptance of former nestmates after swarming. In two out of four replicates, workers originating from the colonies that contained the original wax combs were rejected by guards from the initially comb-less colonies. This suggests that comb wax plays an important role in nestmate recognition. However, the remaining two replicates did not show a response; all former nesmates were still accepted two weeks after artificial swarming.

Colonies of social insects coordinate many activities in response to changing colony needs. One example is the maintenance of pollen stores in the nest by honey bees (Apis mellifera L.). To adjust pollen intake in an appropriate manner, individual foragers must assess the colony's need for pollen. This assessment could be done either directly, through physical contact with larvae and stored pollen, or indirectly, using information obtained from other bees in the colony. We investigated the mechanisms by which foragers assess their colony's need for pollen. We segregated foragers from non-foragers using either a single screen that permitted contact between the two groups of bees, or a double screen that prevented contact. We supplied the segregated foragers in colonies of both of the screen treatment groups with either a comb containing 300 g pollen (P+) or a comb without pollen (P-). To create a need for pollen in the non-forager compartment of each colony, we provided that compartment with combs bearing 3-5 d old larvae but without any pollen. Foragers on combs with pollen returned 3.5% of the time with pollen, while foragers on combs without pollen returned with pollen 20.7% of the time (P LGT 0.005). Foragers able to contact their non-foraging nestmates through a single screen (S1) returned with pollen 12.6% of the time, while foragers prevented from contacting nestmates by a double screen (S2) returned with pollen loads 11.7% of the time (P RGT 0.80). The interaction between the pollen and screen treatments was not significant. These results suggest that foragers adjust their foraging behavior based on their direct assessment of the amount of pollen stored in the colony, and that non-foragers do not provide an excitatory indirect stimulus to foragers.

In order to analyze hygienic behaviour of Apis mellifera L. in worker and drone brood cells, a number of worker and drone larvae, from six honey bee hives were killed with a needle through the cap. The work was done at Coronel Vidal, province of Buenos Aires during spring 1999. Results showed a different hygienic behavior between worker and drone brood cells. There were no significant differences between hives. However, nurse bees emptied significantly more drone brood cells than worker cells, with average remotion rates of 74.04+-1.03% and 70.46+-0.99% for drone and worker cells respectively. This high remotion proportion for drone cells is quite different to results observed for Apis cerana F., which did not hygienize drone brood cells. Results presented in this study could describe a strategy displayed by Apis mellifera nurse bees against the presence of abnormality in brood. In this way honey bees could eliminate rapidly possible pathogenic agents from hives.

The roles of self- versus cross-pollination and honey bee (Apis mellifera L.) foraging behaviour in low nut yield of cashew (Anacardium occidentale L.) were studied in NE Brazil in 1997 and 1998. It was shown that both self- and cross-pollination can set fruits in cashew, but most of fruits originating from self-pollination are shed 9-15 d after pollination, and fruits harvested are primarily from cross-pollination. Honey bees display foraging behaviour in cashew orchards conducive to cross-pollination, but in plantations originating from clonal material they failed to increase fruit yield despite cashew's dependence on insect pollination. It is concluded that cashew has a mechanism of selective abortion through which it discards self-pollinated fruits and that honey bees can contribute to increased fruit yield only when cashew trees of genetically diverse origin are found in the same orchard.

The capacity to generalise between similar but not identical olfactory stimuli is crucial for honey bees, allowing them to find rewarding food sources with varying volatile emissions. We studied bees' generalisation behaviour with odours having different biological values: typical floral odours or alarm compounds. Bees' behavioural and peripheral electrophysiological responses were investigated using a combined proboscis extension response conditioning-electroantennogram assay. Bees were conditioned to pure linalool (floral) or to pure isoamyl acetate (alarm) and were tested with different concentrations of both compounds. Electrophysiological responses were not influenced by conditioning, suggesting that the learning of individual compounds does not rely on modulations of peripheral sensitivity. Behaviourally, generalisation responses of bees conditioned to the alarm compound were much higher than those of bees conditioned to the floral odour. We further demonstrated such asymmetrical generalisation between alarm and floral odours by using differential conditioning procedures. Conditioning to alarm compounds (isoamyl acetate or 2-heptanone) consistently induced more generalisation than conditioning to floral compounds (linalool or phenylacetaldehyde). Interestingly, generalisation between the two alarm compounds, which are otherwise chemically different, was extremely high. These results are discussed in relation to the neural representation of compounds with different biological significance for bees.

The influence of several spatial parameters on the maximal detection distance of a target by approaching foraging honeybees was examined. The roles of target diameter, color and luminance contrasts have been already demonstrated in earlier studies. The present study used, for the first time, dissected flower like targets that differed in addition to diameter (D) and area (pi(D/2)2=Acir) also in the length of contour line (C), the area of the colored "petals" (Acol) and the degree of dissectedness as expressed mainly by the ratio Acol2/C. The color and luminance contrasts were identical for all targets. Our results confirm the importance of size. However, we demonstrate for the first time, that full circular shapes have the greatest maximal detection distance among targets of equal diameters, and even more than dissected targets with equal Acol and double D. The parameter Acol2/C was found as the best predictor of maximal detection distance of vertically presented targets with varying diameter and degree of dissection for honeybee workers. We propose that an increase in the colored area and decrease in contour line is advantageous due to the fact that it increases the amount of contrast that the target as a whole produces against its background.

Paracoccidioidomycosis is the most important systemic mycosis in Latin America. Its etiological agent, Paracoccidoides brasiliensis, affects individuals living in endemic areas through inhalation of airborne conidia or mycelial fragments. The disease may affect different organs and systems, with multiple clinical features, with cell-mediated immunity playing a significant role in host defence. Peritoneal macrophages from BALB/c mice were stimulated with Brazilian or Bulgarian propolis and subsequently challenged with P. brasiliensis. Data suggest an increase in the fungicidal activity of macrophages by propolis stimulation, independently from its geographic origin.

The main targets of the insecticide imidacloprid are neuronal nicotinic acetylcholine receptors (nAChRs) within the insect brain. We tested the effects of imidacloprid on ligand-gated ion channels of cultured Kenyon cells of the honeybee, Apis mellifera. Kenyon cells build up the mushroom body neuropils, which are involved in higher order neuronal processes such as olfactory learning. We measured whole-cell currents through nicotinic and gamma-aminobutyric acid (GABA) receptors using patch-clamp techniques. Pressure applications of imidacloprid elicited inward currents, which were irreversibly blocked by alpha-bungarotoxin. Imidacloprid was a partial nicotinic agonist, since it elicited only 36% of ACh-induced currents and competitively blocked 64% of the peak ACh-induced currents. GABA-induced currents were partially blocked when imidacloprid was coapplied and this block was independent upon activation of nAChRs. Our results identify the honeybee nAChR as a target of imidacloprid and an imidacloprid-induced inhibition of the insect GABA receptor.

The recently developed geometric morphometrics methods represent an important contribution of statistics and geometry to the study of biological shapes. We propose simple protocols using shape distances that incorporate geometric techniques into linear quantitative genetic models that should provide insights into the contribution of genetics to shape variation in organisms. The geometric approaches use Procrustes distances in a curved shape space and distances in tangent spaces within and among families to estimate shape heritability. We illustrate the protocols with an example of wing shape variation in the honeybee, Apis mellifera. The heritability of overall shape variation was small, but some localized components depicting shape changes on distal wing regions showed medium to large heritabilities. The genetic variance-covariance matrix of the geometric shape variables was significantly correlated with the phenotypic shape variance-covariance matrix. A comparison of the results of geometric methods with the traditional multivariate analysis of interlandmark distances indicated that even with a larger dimensionality, the interlandmark distances were not as rich in shape information as the landmark coordinates. Quantitative genetics studies of shape should greatly benefit from the application of geometric methods.

Western Australian eucalypt pollens in this research have low levels of lipid (0.59-1.9%) when compared with many other plant species that have evolved alongside the European honeybee. Eucalypt-pollen lipid was dominant in linoleic acid (35.7-48%). The six other major fatty acids that were present in the lipid were myristic, palmitic, stearic, oleic, linolenic and arachidic acids. Linoleic acid was dominant in eucalypt pollen at average concentrations of 2.77-5.81 mg/g pollen. These results could be of significance to the Australian beekeeping industry in refining disease-management strategies in the light that other researchers have found that 2 economically damaging bee diseases (EFB and AFB) are inhibited by certain concentrations of the acid. Redgum- or marri (Corymbia calophylla)-pollen lipid was also dominated by 2 other known antibacterial fatty acids: myristic (0.25 mg/g pollen) and linolenic (1.06 mg/g pollen), when compared with the other eucalypts studied.

Results from a simple model of a population of varroa mites (Varroa destructor-previously known as Varroa jacobsoni) reproducing in a honeybee colony (Apis mellifera) are compared with previous models. The method considers the choice of appropriate output parameters. Sensitivity analysis was used to rank the input variables in terms of relative importance. In this model, seasonal variation in brood rearing of the host honeybees was found to be more important in determining the mite population growth rate than the reproductive rate of the mites. Simulations with different amounts of drone brood highlight its importance in determining the growth rate of the varroa population. Possible biological control methods that beekeepers can apply are discussed. Simulations with shortened post-capping times (PCTs) of worker brood and drone brood indicate that a reduction of about 10% in the PCTs for drone or worker brood would reduce the mite population growth by about 30 or 60%, respectively. This analysis highlighted some important variables that appear to have been given little consideration by previous workers, such as the start and end time of the brood rearing season. It also showed how sensitivity analysis should be used to indicate the most important areas of further research to fill knowledge gaps.

We observed the impact of bad pollen supply (non-foraging due to artificial rain and pollen removal under poor-foraging conditions) on the survival of honey bee larvae, and on the total development time from egg-laying to the capping of a larval cell. Five days of non-foraging led to cannibalism of larvae younger than 3 days old and to a shortening of the time until larvae were sealed, but 4- and 5-day-old larvae survived even worse pollen supply situations. Manual pollen removal and reduction of income (pollen trap) induced cannibalism of younger larvae. The larvae's mean capping age significantly correlated with the mean pollen income: the less pollen was stored by the hive during the larvae's development, the earlier the larvae were capped. Both behavioral patterns lead to a quick reduction in the amount of unsealed older brood in response to a shortage of available protein. Older larvae have the highest pollen demand, so this strategy compensates for a shortage of supply by reducing demand. Additionally worker jelly gets enriched by protein gained from cannibalism, and the early capping of older larvae saves the oldest part of the brood, which represents the highest broodcare investment.

Worker piping, previously reported only in hives, was observed in swarms as they prepared to liftoff to fly to a new home. Pipers are excited bees which scramble through the swarm cluster, pausing every second or so to emit a pipe. Each pipe consists of a sound pulse which lasts 0.82+-0.43 s and rises in fundamental frequency from 100-200 Hz to 200-250 Hz. Many, if not all, of the pipers are nest-site scouts. The scouts pipe when it is time to stimulate the non-scouts to warm themselves to a flight-ready temperature (35degreeC) in preparation for liftoff. The time-course of worker piping matches that of swarm warming; both start at a low level, about an hour before liftoff, and both build to a climax at liftoff. When we excluded pipers from bees hanging in the cool, outermost layer of a swarm cluster, we found that these bees did not warm up. The form of worker piping that we have studied in swarms differs from the form of worker piping that others have studied in hives. We call the two forms "wings-together piping" (in swarms) and "wings-apart piping" (in hives).

Bees seem to use landmarks to segment familiar routes. They can associate, with a landmark, a memory that encodes the direction and distance of the path segment between that landmark and the next. The expression of the memory results in the performance of a local vector matching the distance and direction of the path segment. The memories of path segments appear to be 'chained' together, so that the performance of one local vector is sometimes sufficient to elicit the subsequent local vector, even in the absence of the associated landmark. We have investigated the effect of visual panoramic context on the expression of local vectors. Bees were trained to fly along a narrow channel to collect sucrose from a feeder positioned partway along it. Panoramic context was provided by various types of patterning on the walls. The channel was partitioned into different segments using landmarks of two kinds: a boundary landmark that marked a change in the pattern on one or both side-walls of the channel, and an isolated landmark, consisting of a baffle through which the bee passed, for which the wall pattern was the same before as after. In tests, we removed the feeder and analysed the search distribution of the bees for various arrangements of landmarks. Altering the spatial relationship between landmarks has different consequences for the two types of landmark. If the final boundary landmark is shifted, the centre of the search distribution shifts by approximately the same amount. Changes in the position of an isolated landmark have a weaker effect. In the absence of the final context, the search is disrupted. We suggest that for local vectors to be expressed the surrounding panoramic context needs to be appropriate. A comparison of search patterns from two different training configurations of landmarks supports the hypothesis that local vector memories merely encode route segments and that global positional coordinates are not linked to landmark memories.

A laelapid and two ascid mite species are recorded and identified as new to science. The laelapid Androlaelaps bayoumi n. sp. was found to be phoretic on honeybee workers, Apis mellifera L., in the Kom - Hamada district, Behira Governorate, Egypt. Blattisocius apis n. sp. was collected from a brood of A. mellifera in Moshtohor district, Qualubia Governorate, Egypt; while B. capsicum n. sp. occurred in association with the immature stages of a psocopterous insect inhabiting the stored hot pepper, Capsicum annuum L. in Zagazig district, Sharkia Governorate, Egypt.

Propolis collected from a cerrado area in Minas Gerais State, Brazil, was subjected to chromatography on silica gel column and to partition between immiscible solvents. Propolis aqueous-ethanolic extract and fractions obtained were tested for inhibitory activity against periodontitis-causing bacteria. All of the assayed bacterium species were susceptible to propolis extract. The two fractionation methodologies yielded fractions which were active against bacteria, with minimum inhibitory concentrations (MIC) ranging from 64 to 1024 mug/ml. TLC and HPLC analyses of the extract and of active fractions showed the presence of phenolic compounds of varied polarity. None of the assayed fractions was more active than the extract, suggesting that the antibacterial activity is probably due to the synergistic effect of several compounds.

We investigated the antifatigue effect of royal jelly (RJ), which had been stored at -20degreeC from immediately after collection, in male Std ddY mice. The mice were accustomed to swimming in an adjustable-current swimming pool, then subjected to forced swimming five times during 2 wk, and the total swimming period until exhaustion was measured. They were separated into three groups with equal swimming capacity, which were administered RJ, RJ stored at 40degreeC for 7 d (40-7d RJ), or the control solution including casein, cornstarch, and soybean oil before swimming. All mice were forced to swim for 15 min once; then the maximum swimming time to fatigue was measured after a rest period. The swimming endurance of the RJ group significantly increased compared with those of the other groups. The mice in the RJ group showed significantly decreased accumulation of serum lactate and serum ammonia and decreased depletion of muscle glycogen after swimming compared with the other groups, whereas there was no significant difference between the 40-7d RJ group and the control group in these parameters after swimming. A quantitative analysis of constituents in RJ showed that 57-kDa protein, which we previously identified as a possible freshness marker of RJ, was specifically degraded in RJ stored at 40degreeC for 7 d, whereas the contents of various vitamins, 10-hydroxy-2-decenoic acid, and other fatty acids in RJ were unchanged. These findings suggest that RJ can ameliorate the physical fatigue after exercise, and this antifatigue effect of RJ in mice seems to be associated with the freshness of RJ, possibly with the content of 57 -kDa protein.

To clarify the molecular basis underlying the neural function of the honeybee mushroom bodies (MBs), we identified three genes preferentially expressed in MB using cDNA microarrays containing 480 differential display -positive candidate cDNAs expressed locally or differentially, dependent on caste/aggressive behavior in the honeybee brain. One of the cDNAs encodes a putative type I inositol 1,4,5-trisphosphate (IP3) 5-phosphatase and was expressed preferentially in one of two types of intrinsic MB neurons, the large-type Kenyon cells, suggesting that IP3-mediated Ca2+ signaling is enhanced in these neurons.

The caste-specific regulation of vitellogenin synthesis in the honeybee represents a problem with many yet unresolved details. We carried out experiments to determine when levels of vitellogenin are first detected in hemolymph of female castes of Apis mellifera, and whether juvenile hormone and ecdysteroids modulate this process. Vitellogenin levels were measured in hemolymph using immunological techniques. We show that in both castes the appearance of vitellogenin in the hemolymph occurs during the pupal period,but the timing was different in the queen and worker. Vitellogenin appears in queens during an early phase of cuticle pigmentation approximately 60h before eclosion, while in workers the appearance of vitellogenin is more delayed, initiating in the pharate adult stage,approximately 10h before eclosion. The timing of vitellogenin appearance in both castes coincides with a slight increase in endogenous levels of juvenile hormone that occurs at the end of pupal development. The correlation between these events was corroborated by topical application of juvenile hormone. Exogenous juvenile hormone advanced the timing of vitellogenin appearance in both castes,but caste-specific differences in timing were maintained. Injection of actinomycin D prevented the response to juvenile hormone. In contrast, queen and worker pupae that were treated with ecdysone showed a delay in the appearance of vitellogenin. These data suggest that queens and workers share a common control mechanism for the timing of vitellogenin synthesis, involving an increase in juvenile hormone titers in the presence of low levels of ecdysteroid.

The biodiversity of honeybee (Apis mellifera) populations from Tenerife (Canary Islands, Spain) has been assessed by restriction analysis of a mitochondrial non-coding intergenic region. Seventy-nine colonies were analysed from thirteen apiaries in six populations that have been kept from recent queen introduction. The length and restriction pattern of the PCR amplified products of the intergenic region identified four mitochondrial haplotypes. One of these haplotypes shows the same restriction pattern and composition of the intergenic region carried by honeybees belonging to the African lineage. Two haplotypes are characterised by a particular intergenic region found with high frequency in the Canarian populations. The haplotype representative of the East European honeybee lineage shows a frequency of 35%, thus indicating introduction of queen honeybees. The finding of this haplotype in Canarian honeybees suggests that hybridisation between the endemic Apis mellifera populations and imported bees is occurring in Tenerife.

We have previously shown that 57-kDa protein in royal jelly (RJ) was specifically degraded in proportion to both storage temperature and storage period, and we suggested that it could be useful as a marker of freshness of RJ (Kamakura, M., Fukuda, T., Fukushima, M. and Yonekura, M., Biosci. Biotechnol. Biochem., 65, 277-284 (2001).). Here, we investigated the effects of various proteinase inhibitors on proteinase activity in RJ and on the specific degradation of 57-kDa protein during storage. Ethylenediaminetetraacetic acid (EDTA), but not other inhibitors, inhibited the proteinase activity in RJ, and dose-dependently suppressed storage-dependent degradation of 57-kDa protein. These results suggest that EDTA inhibits a specific proteinase activity in RJ, thereby suppressing the degradation of 57-kDa protein during storage at high temperature.

Pollen collection in honey bees is regulated around a homeostatic set -point. How the control of pollen collection is achieved is still unclear. Different feedback mechanisms have been proposed but little is known about the experience of pollen foragers in the hive. A detailed documentation of the behavior of pollen foragers in the hive under different pollen need conditions is presented here. Taking a broad observational approach, we analyze the behavior of individual pollen foragers in the hive between collecting trips and quantify the different variables constituting the in -hive stay. Comparing data from two colonies and 143 individuals during experimentally induced times of low vs. times of high pollen need, we show that individual foragers modulate their in-hive working tempo according to the actual pollen need of the colony: pollen foragers slowed down and stayed in the hive longer when pollen need was low and spent less time in the hive between foraging trips when pollen need by their colony was high. Furthermore, our data show a significant change in the trophallactic experience of pollen foragers with changing pollen need conditions of their colony. Pollen foragers had more short ( LGT 3 s) trophallactic contacts when pollen need was high, resulting in an increase of total number of trophallactic contacts. Thus, our results support the hypothesis that trophallactic experience is one of the various information pathways used by pollen foragers to assess their colony's pollen need.

We evaluated the influence of pollen-based cues on the foraging decisions made by honeybees using a series of two-choice bioassays, performed within a highly controlled indoor environment. We examined behaviours related to the choice and collection of pollen by foragers among six floral species and three artificial substrates (pollen analogues). First, we evaluated the responses of honeybees to the odours produced by different pollens (or pollen analogues) and pollen lipid extracts. Honeybees displayed similar levels of preference to the odours produced by all pollen species over those of pollen analogues, with a similar pattern of response shown to their extracts. We then evaluated behaviours of foragers in response to variation in particle size, using soybean meal that was ground and sifted to create a hierarchy of particle size classes. Bees preferred particle sizes below 150 mum, but the greatest response was shown for those particle sizes below 45 mum. We also assayed the effect of varying protein content on the foraging decisions made by bees by mixing soy flour with different proportions of cellulose powder. Foragers, however, were incapable of discriminating protein content. We determined changes in the response of foragers to different levels of handling time using different sized screens through which bees were forced to crawl to reach an attractive pollen odour source. In these tests, pollen-seeking behaviours were seen to decrease with increases in handling time. When odour was presented simultaneously with other stimuli, it was the primary and overriding cue used by bees to select pollen. These results suggest that individual honeybee foragers do not discriminate among pollen sources based on intrinsic differences in quality, but instead evaluate cues that may increase their efficiency of collection and recruitment to such a food resource.

The vibration signal of the honeybee functions as 'modulatory communication' because it elicits a general increase in activity that may help integrate the behaviour of workers that perform different, interrelated task sets. Workers that produce vibration signals contact numerous other bees, some of which receive the signal while others are 'bypassed' (antennated but not vibrated). Vibrating bees may therefore select among potential recipients. We monitored vibration signal behaviour in six observation colonies to investigate the possible selection of recipients by vibrating bees and the factors that might influence these choices. Vibrating bees roamed throughout the nest and bypassed more than half of all workers contacted. Vibration signals were not directed towards specific worker age groups. There were no differences in the mean age of vibrated versus bypassed workers or the proportion of recipients that were of preforaging versus foraging age. The likelihood of receiving vibration signals was influenced by recipient activity level. Significantly more workers were vibrated if they were inactive versus active when contacted by a signalling bee. Signal production was not consistently influenced by relatedness. Vibrating bees from only a single patriline in one of our study colonies were more likely to perform signals on supersisters than on half-sisters. In all other colonies no kin preferences were observed during signal performance. Thus, vibrating bees may choose among potential recipients and direct their signals towards inactive workers of all ages and levels of relatedness. This, in combination with their movement throughout the colony, could help to activate simultaneously multiple worker groups that perform interdependent tasks, but which may be spatially segregated in the nest.

Crude venoms from three highly evolved aculeate species: Apis mellifera (highly social bees), Bombus morrisoni (eusocial bees), and Anthophora pauperata (solitary bees), were used for conducting this study to compare the effects of honey bee, bumble bee, and solitary bee venom on toad cardiac muscle activity. In addition, these venoms were tested on rat whole blood in order to determine their ability to induce red blood cell haemolysis. The main toxic effects on isolated toad heart were monitored by ECG after perfusion with different concentrations of each bee venom, and are represented as a decrease in the heart rate (HR) accompanied by an elongation in the P-R interval. A gradual and progressive increase in R -wave amplitude was also noted. Several electrocardiographic changes were noted 5-30 min after envenomation with any of the bee venoms. The mechanism of action of the three bee venoms was determined by direct application of atropine, nicotine, or verapamil to the isolated toad hearts. Comparison of the three venoms revealed that Anthophora pauperata venom is the most effective venom in inducing bradycardia, and it has the strongest negative dromotropic effect. Apis mellifera venom demonstrates the most positive inotropic effect of the three venoms. The effects of bee venom on the blood indices of erythrocyte osmotic fragility (EOF) and plasma albumin levels were studied after incubation of rat blood with each venom. It was noticed that RBCs decreased while Hb content, HCT, MCV, MCH, and MCHC increased, although this change did fluctuate and was not significant. A nonsignificant decrease in EOF was noted after 60 min with any of the venoms used. Incubation of rat whole blood with 1 mug/ml of any of the bee venom solutions revealed a highly significant decrease in plasma albumin levels. It can be concluded that venoms from the three species of bees we tested have negative chronotropic and dromotropic effects on isolated toad heart, with Anthophora pauperata being the most potent. In addition, the venoms have positive inotropic effects with Apis mellifera being the most potent. The nonsignificant effects of venom on blood profiles and erythrocyte osmotic fragility, combined with the significant decrease in plasma albumin level suggest a protective effect of plasma albumin against bee venom induced toxicity to erythrocytes.

The aim of this study was to investigate the effect of ZnSO4 on the function of contact chemosensitive and olfactory sensilla of the worker honeybee antennae. The effect of ZnSO4 on contact chemosensitive sensilla was tested behaviorally using the proboscis extension response and that on olfactory sensilla using electroantennogram recordings. We showed that antennal ZnSO4-treatment significantly reduced the sugar-elicited proboscis extension response but did not reduce olfactory evoked electroantennogram responses. Both results indicate that ZnSO4 selectively blocks contact-chemosensory and not olfactory perception. We suggest that ZnSO4 ablation will be a powerful tool to investigate the role of contact chemosensory and olfactory sensilla in short range communication within the honeybee colony.

In the present study, the performance of two bee species, the honeybee Apis mellifera and the leaf-cutter bee Megachile rotundata, in discriminating among various closed (convex) shapes was examined systematically for the first time. Bees were trained to each of five different shapes, a disc, a square, a diamond and two different triangles, all of the same area, using fresh bees in each experiment. In subsequent tests, the trained bees were given a choice between the learned shape and each of the other four shapes. Two sets of experiments were conducted with both species. In the first, solid black shapes were presented against a white background, thus providing a high luminance contrast. In the second, the shapes carried a random black-and-white pattern and were presented 5 cm in front of a similar pattern, thus producing motion contrast, rather than luminance contrast, against the background. The results obtained with the solid shapes reveal that both bee species accomplish the discrimination, although the performance of the honeybee is significantly better than that of the leaf-cutter bee. Furthermore, the effectiveness of the various shapes differs between the two species. However, in neither species is the discrimination performance correlated with the amount of overlap of the black areas contained in the various pairs of shapes, suggesting that, in our experiments, shape discrimination is not based on a template-matching process. We propose that it is based on the use of local parameters situated at the outline of the shape, such as the position of angles or acute points and, in particular, the position and orientation of edges. This conclusion is supported by the finding that bees of both species accomplish the discrimination even with the patterned shapes. These shapes are visible only because of the discontinuity of the speed of image motion perceived at the edge between the shape and the background.

The ability of Varroa destructor to reproduce in the African honey bee Apis mellifera scutellata was studied. In addition, the effects of space within the brood cell and short brood developmental time on mite reproduction, was investigated using A. m. scutellata cells parasitised by a A. m. capensis worker pseudo-clone. In A. m. scutellata worker cells Varroa produced 0.9 fertilised females per mother mite which is the same as found in susceptible European honey bees, but greater than the 0.4 produced in cells containing the pseudo-clone. Low mite reproductive success in cells containing pseudo-clone was mainly as a result of increased mite mortality. This was caused by male protonymphs and some mothers becoming trapped in the upper part of the cell due to the pseudo-clone being 8% larger than their host and not due to their short developmental time. Therefore, mite populations in South African A. m. scutellata and A. m. capensis honey bees are expected to increase to levels observed in Europe and USA.

Programmed cell death in the worker ovary of Apis mellifera reduces the number of ovarioles during metamorphosis from 150-200 primordia to less than 10. In contrast, practically all ovarioles in the ovary of queens survive to the adult stage. The correct formation and persistence of polyfusomes has been suggested as a critical factor for ovariole survival. We have analyzed the developmental dynamics of F-actin and alpha-spectrin in fusomes of queen and worker larvae, and in juvenile-hormone-treated worker larvae. Small fusomes containing actin and spectrin can be detected in the ovaries of fourth instar larvae in both castes. After molting to the fifth instar, the actin-spectrin association persists in the enlarged fusomes of queen ovarioles. In workers, actin dissociates from the fusomal and cortical alpha-spectrin. Coinciding with the appearance of apoptosis markers, large agglomerates of actin are detectable in worker ovarioles. Treatment of fourth-instar worker larvae with juvenile hormone rescues ovarioles from apoptosis and maintains the actin-spectrin association. Juvenile-hormone-dependent actin-spectrin interaction is thus one of the earliest steps in the differentiation of a polymorphic ovary. Plasticity in ovariole numbers as a result of hormone-dependent fusome formation may be a more widespread phenomenon in insects, extending beyond caste polymorphism in highly eusocial Hymenoptera.

1,1-bis-(p-Chlorophenyl)-2,2,2-trichloroethane (DDT) inhibited the ATP hydrolytic activity of the ATP synthase from a DDT-susceptible insect (Apis mellifera) as well as a DDT-tolerant insect (Spodoptera littoralis), and from rat liver and bovine heart in a parallel way to its insecticidal properties and selectivity of action. Inhibition of the ATPase activity of these preparations by DDT was parallel to the poisoning of the source organism with DDT. Furthermore, both the inhibition and poisoning of insects were affected similarly by temperature. Inhibition of the insect enzyme activity by DDT was specific and differed from that by oligomycin or N,N-dicyclohexylcarbodi-imide (DCCD). PAGE analysis of the various preparations of the enzyme showed that the inhibition of the enzyme activity by DDT was associated with the presence of a selective protein band with an apparent molecular mass of 23 kDa. This protein band exists in the preparations from the DDT-susceptible insects but was absent from the preparations of the enzyme from the DDT-insensitive sources. Removal of this protein band from the enzyme rendered its activity insensitive to inhibition by DDT. The protein was purified directly from mitochondria and the DDT sensitivity was reconstituted upon its addition to the DDT -insensitive F1-ATPase. We conclude that this identified protein of the ATP synthase is the DDT target protein in insects.

Catalase (CAT), glutathione S-transferase (GST) and superoxide dismutase (SOD) activities were determined in postmitochondrial fractions of tissue homogenates (spermathecae, muscle and ventriculi), in hemolymph plasma, and in semen of honey bees. The highest CAT activity was found in semen (4.8 mU/mug fresh weight), and the enzyme was confined to the spermatozoa. CAT and GST activities of ventriculi exceeded those of other tissues and hemolymph, CAT being highest in mated queen ventriculi (2.7 mU/mug) and GST highest in worker ventriculi (10 mU/mg). Spermathecae of mated queens had higher CAT and GST activities (0.84 mU/mug, and 2.4 mU/mg, respectively) than virgin spermathecae (0.15 mU/mug, and 1.6 mU/mg). SOD activities (15-59 mU/mug) varied less than activities of CAT or GST between tissues. Seminal plasma contained two thirds of the total SOD activity of semen and one third was in the spermatozoa. The substantial activities of all three enzymes in spermathecae of mated queens suggest their involvement in the long-term protection of the spermatozoa from oxidative stress.

We measured the age at onset of foraging in colonies derived from three races of European honey bees, Apis mellifera mellifera, Apis mellifera caucasica and Apis mellifera ligustica, using a cross-fostering design that involved six unrelated colonies of each race. There was a significant effect of the race of the introduced bees on the age at onset of foraging: cohorts of A. m. ligustica bees showed the earliest onset, regardless of the race of the colony they were introduced to. There also was a significant effect of the race of the host colony: cohorts of bees introduced into mellifera colonies showed the earliest onset of foraging, regardless of the race of the bees introduced. Significant inter-trial differences also were detected, primarily because of a later onset of foraging in trials conducted during the autumn (September-October). These results demonstrate differences among European races of honey bees in one important component of colony division of labor. They also provide a starting point for analyses of the evolution of division of labor under different ecological conditions.

The action of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) on the isolated heart of the frog (Rana ridibunda) and two insects, the honeybee (Apis mellifera macedonica) and the beetle (Tenebrio molitor), was investigated using basic electrophysiological methods. The results of this study showed that a concentration of 1 muM 2,4-D was required to reduce the force and the frequency of the isolated heart of the honeybee to about 70% of the initial contraction in less than 20 min. To cause the same effects on the atria of the frog, 45 muM 2,4-D was required and on the isolated heart of the beetle, over 1000 muM of 2,4-D. The presence of an extensive system of gap junctions found in the honeybee is most probably the cause of the unusual sensitivity of its heart to 2,4-D, compared with the heart of the beetle, where no gap junctions were identified.

When not satiated prior to training, there were no differences between foragers and nurse honey bees in the acquisition of an appetitively based conditioned response in an olfactory associative learning assay, but when satiated foragers showed faster acquisition than did nurses. Satiation -related differences between foragers and nurses were more a function of behavioral state than age, because satiated precocious foragers also showed faster acquisition rates than did satiated nurse bees, despite their similar ages. Tests of sucrose responsiveness and retention of conditioned responses indicate that the observed performance differences between nurses and foragers were more likely due to differential sensitivity of sensory and motor processes related to satiation rather than differences in cognitive ability.

Fresh, one and two-year old Apis mellifera honey samples were analyzed for various quality parameters viz., moisture content, acidity, specific gravity, ash content and total reducing sugars to see the effect of storage on honey quality. No significant effect of storage was observed on honey quality upto two years of storage. Values remained within the permissible limits given by Bureau of Indian Standards.

Propolis is a complex mixture of the beehive produced by the honeybee (Apis mellifera), gathering and transforming the bud exudates, by mixing them with waxy substances; used in the sepsis of the hive. We investigate here the botanical origin of samples of propolis by microscopic analysis of the pollen grains and leaf fragments found therein. The honeybees gather mainly Salix humboldtiana and Eucalyptus globulus resins in all sites (Cuncumen, Santa Amalia, San Carlos, Loncolemu, Quillota, Corintos, Salto de Agua, Santa Cruz, Paine and Tanguao). There were other species gathered as sources of propolis, but they were not represented in all sites. These were: Quillaja saponaria, Lithrea caustica, Baccharis linearis and Populus alba. In the network consisting of ten hives, major species were: S. humboldtiana, Q. saponaria, L. caustica, B. linearis, Peumus boldus, Buddleja globosa, Escallonia rubra, Eucalyptus globulus and P. alba.

The location and morphological features of the blood cells found in the pupal ovary of workers and queens of Apis mellifera are described in relationship with their probable function in the ovary differentiation. The hemocytes from inside the ovarioles are different in both castes. In queens their morphology suggest an action in the tunica propria production, while in workers it suggest a phagocytic activity. The hemocytes present in the intersticial tissue are phagocytes in both castes, and may be responsible by the ovary shapping during metamorphosis.

We previously identified a gene, Mblk-1, that encodes a putative transcription factor with two DNA-binding motifs expressed preferentially in the honeybee brain (H. Takeuchi et al., Insect Mol. Biol. 10, 487-494 (2001)). In the present study, we identified its preferred binding sequence as 5'-CCCTATCGATCG-ATCTCTACCT-3' and characterized its DNA -binding properties using truncated Mblk-1 mutants. An electrophoretic mobility shift assay revealed that the full-length Mblk-1 binds to the sequence with high affinity, whereas each truncated DNA-binding motif of Mblk-1 binds with much lower affinities. An in vitro pull-down assay indicated that each DNA-binding motif affords homodimeric bindings, suggesting that Mblk-1 functions as a dimer.

In insects, the transport of airborne, hydrophobic odorants and pheromones through the sensillum lymph is accomplished by olfactory-binding proteins (OBPs). We report the structural characterization of a honeybee OBP called ASP1 found in workers and drones, previously observed to bind queen pheromone components. A novel method based on ion-spray mass spectrometry analysis of cyanylation-induced cleavage products of partially reduced protein with Tris(2-carboxyethyl)phosphine was needed to determine the recombinant ASP1 disulfide bond pairing. It was observed to be Cys(I) -Cys(III), Cys(II)-Cys(V), Cys(IV)-Cys(VI), similar to those already described for other OBPs from honeybee and Bombyx mori suggesting that this pattern occurs commonly throughout the diverse family of insect OBPs. Circular dichroism revealed that ASP1 is an all-alpha protein in accordance with NMR preliminary data, but unlike lipocalin-like vertebrate OBPs.

Biennial caraway (Carum carvi L.) is a specialty spice crop in Saskatchewan, yet little was known about fundamental agronomic traits, such as its flowering phenology, plant density, attraction to potential pollinators, and prospective honey yield. At five commercial fields in 1998 and 1999, biennial caraway flowered for 7 wk, beginning in late May or early June and finishing by early to mid-July. Under optimal conditions, and assuming intense foraging activity by honey bees (Apis mellifera L.), caraway might yield 70-134 kg honey ha-1. However, weights of colonies near fields of caraway (0.47-4.2 hives ha-1) changed little while honey bees were predominant foragers on that crop. Then, in the second half of the caraway flowering period, when honey bees had almost deserted those fields as indicated by observation and pollen-trap analyses, hive weights rose steadily due to a switch to nearby crops of canola (Brassica spp.) and sweet clover (Melilotus spp.), which had begun to flower. Whereas biennial caraway is rated as negligible to only moderate for its honey potential in Saskatchewan, 83% of honey bees visiting caraway florets gathered pollen. Moreover, caraway pollen entering hives averaged 11% of total pollen (dry weight) over the entire flowering period of the crop, but 36.5% during the first half of flowering phenology, suggesting that biennial caraway may constitute a valuable source of protein for honey bees, particularly during colony build-up in spring.

Sperm quality plays an important role in vertebrates in determining which male has the advantage when two or more males compete to fertilize a female's ova. In insects, however, the importance of sperm quality has never been considered, despite sperm competition being widespread and well studied in this group. We tested the hypothesis that sperm viability, measured as the proportion of live sperm, covaried with the intensity of sperm competition in insects. In a pairwise comparison of seven closely related species pairs, each comprising a monandrous and a polyandrous species (i.e., with and without sperm competition, respectively), we found that in all cases the polyandrous species had a higher proportion of live sperm in their sperm stores. The distribution of the percentage of live sperm showed considerable inter- and intraspecific variation, suggesting that, all else being equal, males will vary in their ability to fertilize ova on the basis of sperm viability alone. Our results suggest that sperm viability is one of a suite of male adaptations to sperm competition in insects.

The primary olfactory brain center, the antennal lobe (AL) in insects or the olfactory bulb in vertebrates, is a notable example of a neural network for sensory processing. While physiological properties of the input, the olfactory receptor neurons, have become clearer, the operation of the network itself remains cryptic. Therefore we measured spatio -temporal odor-response patterns in the output neurons of the olfactory glomeruli using optical imaging in the honeybee Apis mellifera. We mapped these responses to identified glomeruli, which are the structural and functional units of the AL. Each odor evoked a complex spatio-temporal activity pattern of excited and inhibited glomeruli. These properties were odor- and glomerulus-specific and were conserved across individuals. We compared the spatial pattern of excited glomeruli to previously published signals, which derived mainly from the receptor neurons, and found that they appeared more confined, showing that inhibitory connections enhance the contrast between glomeruli in the AL. To investigate the underlying mechanisms, we applied GABA and the GABA-receptor antagonist picrotoxin (PTX). The results show the presence of two separate inhibitory networks: one is GABAergic and modulates overall AL activity, the other is PTX -insensitive and glomerulus-specific. Inhibitory connections of the latter network selectively inhibit glomeruli with overlapping response profiles, in a way akin to "lateral" inhibition in other sensory systems. Selectively inhibited glomeruli need not be spatial neighbors. The net result is a globally modulated, contrast-enhanced and predictable representation of odors in the ol-factory output neurons.

The amount and type of pollen collected during the period of apple bloom (25-31 May, 1995) were determined for honey bee colonies of Buckfast and Ontario stocks that had been matched on the basis of brood area. The Buckfast colonies collected 62% more pollen (approximately 18,770 more pollen foraging trips per colony per day) than the Ontario colonies. The proportion of apple pollen generally decreased with increased distance of the hives to the orchard. The results demonstrate that Buckfast bee colonies can effectively pollinate spring fruit crops in Ontario.

The acceptance of one and two day old larvae in upper and lower bars of the grafted frames were studied among the sugar and control groups of feeding. The percentage of accepted larvae that were grafted with dilute royal jelly among groups showed statistically difference between acceptance of 1 and 2 day old larvae among the upper and lower bar of the grafted frames. The groups accepted more two-day-old larvae as compared to one-day-old larvae. Moreover more larvae were accepted in lower bar as compared to upper bar of the grafted frames.

The intensification of agriculture has led to declines in species diversity and abundance within groups of certain flora and fauna. Bumblebees (Bombus spp.) are one group where a decline has been documented, and it is thought to be attributable to a decrease in forage resources and potential nest sites. As bumblebees play an important role in the pollination of many entomophilous crops, this decline could impact on agricultural productivity. We examined the role of naturally regenerated field margins in providing forage plants on land where nectar resources are otherwise impoverished. The following question was addressed - Are naturally regenerated unsprayed field margins more attractive to foraging bumblebees and honeybees than cropped field margins managed as conservation headlands? Significantly more bees visited naturally regenerated field margins than cropped field margins. Honeybees (Apis mellifera), Bombus terrestris, and Bombus lapidarius were the most commonly observed bee species. Different wildflower species within the naturally regenerated margins varied greatly in relative number of visits received, and bumblebee species were found to prefer different flower species to honeybees. The potential role that naturally regenerated field margins could play in the conservation of bumblebee species, and the implications for other species of flora and fauna, are discussed.

The bee fauna of a restrict area of Lowland Region of Maranhao was studied. Monthly samples were performed with entomological net and baits trap with attractive compounds, totalling 288 hours of sampling. A total of 839 individuals belonging to 38 species of the bee families Apidae, Megachilidae, Halictidae, Andrenidae and Colletidae were collected on flowers and 72 individuals (11 species) of Euglossinae in baits trap. Scaptotrigona flavisetis Moure, Trigona pallens Cockerell and Apis mellifera Linnaeus were most frequent species in the area. Bee frequencies showed various patterns of seasonality, i.e. the period in which most bees of S. flavisetis were observed were January and October, T. pallens in January and February and A. mellifera in April. Euglossa (E.) cordata and E. (E.) gr. modestior were the most frequent species collected in baits traps and Eucaliptol was the most attractive compound.

Evidence from field wasps and bumblebees appoints the endocrine system as a mediator between dominance status and ovarian activity in primitively social Hymenoptera. In this comparative study on ecdysteroid titers in the highly social honey bee, Apis mellifera, and a stingless bee, Melipona quadrifasciata, we focussed on the relationship between the ecdysteroid titer, social conditions (presence or absence of the queen), and ovary activity. In contrast to bumblebees, ecdysteroid titers in honey bee and stingless bee workers were either not altered, or dropped to even lower levels after the queen was removed. We also did not detect differences between virgin queens and mated, egg laying queens. These results suggest that ecdysteroids may have lost most of their reproductive functions - yet gained functions in larval caste differentiation - as higher levels of social organization were attained in the evolution of social insects. The observation that ecdysteroid titers are transiently elevated in young workers adds a new, yet functionally still speculative facet to hormonal regulation in insect societies.

Social insect colonies reallocate labor in response to changing environmental circumstances. This study addresses the reallocation of labor by middle-age honeybees in response to heat stress. I tested the hypothesis that the additional labor required to respond to heat stress is obtained by reallocating labor away from unrelated tasks (task switching), activating reserve labor, or both. I found that task switching plays the primary role in this process. Although self-grooming decreased, other indicators of inactivity increased or remained unchanged, leaving the role of reserve labor ambiguous. I also explored the relative importance of specialists versus generalists in the production of work. Wax working, a common task among middle-age workers, was used as a model. I found that although there is a distinct group of wax specialists, they contributed only 19.5% of the total number of wax-working observations. Most wax working was found to be performed by generalists. In addition, I tested for a distinct group of reserve specialists. I found that although activity rates differed between individuals, there was no evidence for a stable group of reserve specialists. The high rate of task switching, in both stressed and unstressed environments, observed in this study highlights the possible significance of frequent task quitting as an organizing principle in the allocation of labor in social-insect colonies.

Contrary to the theory of rational choice, adding an alternative to a set of available options often affects people's judgement of the preexisting options. Here, we show that honeybees (Apis mellifera) and gray jays (Perisoreus canadensis) are also influenced by the addition of an option to a choice set (i.e., by a change in local context). Like humans, our subjects violated basic properties of rational choice. Their relative preference between two original options changed with the introduction of a third, relatively unattractive option. Such context-dependent choice violates the constant-ratio rule. Our subjects increased their relative preference for the more similar of two alternatives, contrary to the similarity hypothesis. The jays also increased their absolute preference for the more similar of two alternatives, in violation of regularity. Thus, the principle of irrelevant alternatives, which assumes that preference between options does not depend on the presence or absence of other options, is violated not only by humans, but also by an invertebrate and a nonhuman vertebrate. These findings contradict the view that nonhuman animals should be immune to such psychological effects and that they should conform with normative accounts, such as rationality or optimal-foraging theory, because their decision-making processes are evolutionarily adaptive. We discuss the potential generality of context -dependent effects and suggest that such effects should be incorporated into decision-making models in behavioral ecology.

Apple (Malus domestica) has a gametophytically determined self -incompatibility (SI) system, which limits inbreeding. As a result, apple fruit-set is dependent on effective cross-pollination, which may be enhanced by honeybees (Apis mellifera) Excess pollination results in over -cropping, leading to many small fruit, regarded as of low quality. On the other hand insufficient pollination is also possible, and is manifested by low crop production. In the present work, characteristics of nectar reward and floral morphology revealed that 'Jonathan' and 'Topred' flowers had similar nectar constitutions. However, honeybee behaviour was totally different in the two cultivars. 'Jonathan' flowers attracted fewer honeybees but, due to their anther arrangement, more of the flowers were approached from the top by honeybees collecting nectar than in 'Topred'. This finding demonstrates the importance of determining the pollination efficiency to achieve optimum honeybee management, in terms of the number of honeybee colonies required for sufficient pollination and minimum fruit thinning.

We have isolated a novel family of insect-selective neurotoxins that appear to be the most potent blockers of insect voltage-gated calcium channels reported to date. These toxins display exceptional phylogenetic specificity, with at least a 10,000-fold preference for insect versus vertebrate calcium channels. The structure of one of the toxins reveals a highly structured, disulfide-rich core and a structurally disordered C -terminal extension that is essential for channel blocking activity. Weak structural/functional homology with omega-agatoxin-IVA/B, the prototypic inhibitor of vertebrate P-type calcium channels, suggests that these two toxin families might share a similar mechanism of action despite their vastly different phylogenetic specificities.

Imidacloprid is a systemic nitroguanidine insecticide that belongs to the neonicotinoid family. As an agonist of the acetylcholine receptor, it attacks the insect nervous system and is extremely effective against various sucking and mining pests. Oral acute and chronic toxicity of imidacloprid and its main metabolites (5-hydroxyimidacloprid, 4,5 -dihydroxyimidacloprid, desnitroimidacloprid, 6-chloronicotinic acid, olefin, and urea derivative) were investigated in Apis mellifera. Acute intoxication by imidacloprid or its metabolites resulted in the rapid appearance of neurotoxicity symptoms, such as hyperresponsiveness, hyperactivity, and trembling and led to hyporesponsiveness and hypoactivity. For acute toxicity tests, bees were treated with doses of toxic compounds ranging from 1 to 1,000 ng/bee (10-10,000 mug/kg). Acute toxicity (LD50) values of imidacloprid were about 60 ng/bee (600 mug/kg) at 48 h and about 40 ng/bee (400 mug/kg) at 72 and 96 h. Out of the six imidacloprid metabolites tested, only two (5-hydroxyimidacloprid and olefin) exhibited a toxicity close to that of imidacloprid. Olefin LD50 values were lower than those of imidacloprid. The 5-hydroxyimidacloprid showed a lower toxicity than imidacloprid with a LD50 four to six times higher than that of imidacloprid. Urea also appeared as a compound of nonnegligible toxicity by eliciting close to 40% mortality at 1,000 ng/bee (10,000 mug/kg). However, no significant toxicity was observed with 4,5 -dihydroxyimidacloprid, 6-chloronicotinic acid, and desnitroimidacloprid in the range of doses tested. To test chronic toxicity, worker bees were fed sucrose solutions containing 0.1, 1, and 10 mug/L of imidacloprid and its metabolites for 10 d. Fifty percent mortality was reached at approximately 8 d. Hence, considering that sucrose syrup was consumed at the mean rate of 12 mul/d and per bee, after an 8-d period the cumulated doses were approximately 0.01, 0.1, and 1 ng/bee (0.1, 1, and 10 mug/kg). Thus, all tested compounds were toxic at doses 30 to 3,000 (olefin), 60 to 6,000 (imidacloprid), 200 to 20,000 (5-OH-imidacloprid), and RGT 1,000 to 100,000 (remaining metabolites) times lower than those required to produce the same effect in acute intoxication studies. For all products tested, bee mortality was induced only 72 h after the onset of intoxication.

A study of aspects of phenology, pollination biology and reproduction of Merremia aegyptia was performed at Fazenda Catalunha, Santa Maria da Boa Vista, PE, from March 1995 to July 1997. The species is an annual liana, with cornucopia pattern of flowering. Peak flowering occurs at the end of March and the beginning of April and coincides with the end of the wet season. The cymose inflorescences have the main axes elongated, exposing the flowers well out the foliage. The flowers are infundibuliform, white, scentless and produce little nectar. Anthesis is diurnal. The flowers open at around 04:30 to 5:00 A.M. and remain approximately seven hours, being ephemeral. The most frequent visitors are bees (Apidae and Halictidae). Apis mellifera and Trigona spinipes were considered the main pollinators. M. aegyptia is facultatively autogamous, producing fruits either after self (30%) or cross (60%) manual pollination.

Relocation of the Cape honeybee, Apis mellifera capensis, by bee-keepers from southern to northern South Africa in 1990 has caused widespread death of managed African honeybee, A. m. scutellata, colonies. Apis mellifera capensis worker bees are able to lay diploid, female eggs without mating by means of automictic thelytoky (meiosis followed by fusion of two meiotic products to restore egg diploidy), whereas workers of other honeybee subspecies are able to lay only haploid, male eggs. The A. m. capensis workers, which are parasitizing and killing A. m. scutellata colonies in northern South Africa, are the asexual offspring of a single, original worker in which the small amount of genetic variation observed is due to crossing over during meiosis (P. Kryger, personal communication). Here we elucidate two principal mechanisms underlying this parasitism. Parasitic A. m. capensis workers activate their ovaries in host colonies that have a queen present (queenright colonies), and they lay eggs that evade being killed by other workers (worker policing)-the normal fate of worker-laid eggs in colonies with a queen. This unique parasitism by workers is an instance in which a society is unable to control the selfish actions of its members.

Hydroxyurea (HU) treatment of first instar honeybee larvae was previously shown to cause mushroom body (MB) ablations. Predominantly, either one or both median MB subunits were ablated. This prompted us to analyze the effects of asymmetrical or symmetrical HU-induced MB ablation on both the morphology of the brain and on the level of three proteins (synapsin, PKA RII, and PKC), which are considered to play a role in synaptic plasticity, learning, and memory. In brains with one median MB subunit missing the volume of the overall MB calyx neuropil in the lesioned side was diminished by 35%. This strong reduction occurred although the remaining lateral MB calyx of the lesioned brain side was found to be significantly larger than that of the intact side. Accordingly, in brains with both median MB subunits missing the size of the remaining lateral calyces increased. The various types of MB ablation differentially affected the amounts of synapsin, PKA RII, and PKC expressed in the central brain. In animals with bilateral and thus symmetrical MB ablation (both median calyces ablated) the protein amount was found to be similar to that in control animals. However, unilateral MB ablation causes an increase in the amounts of the tested proteins in the intact brain side, while the levels in the ablated side were the same as in control animals. These findings not only show that HU-induced ablation of MB subunits is accompanied by volume changes and by changes in protein expression, but also suggest that these processes are highly regulated between the brain sides. The latter is of general importance in understanding the potential contribution of the MB subunits to learning and memory and their interaction between the brain sides.

The N-linked oligosaccharides were released from the phospholipase A2 (PLA) with glycopeptidases and reductively aminated with the chromophore, p -aminobenzoic acid ethyl ester (ABEE). The ABEE-labeled oligosaccharides were separated by microbore high-performance liquid chromatography (mu -HPLC) using a reversed-phase column and analyzed by electrospray mass spectrometry. Differentiation between alpha-1,3 and alpha-1,6 core -fucosylated glycans was achieved by comparison the glycans released by glycopeptidases peptide-N-glycanase A (PNase A) and peptide-N-glycanase F (PNase F). All N-linked oligosaccharides except 3B and 3C could be identified in this approach. The analysis of PLA oligosaccharides from the venom of individual bees indicated that glycosylation patterns between the younger and the older bees were similar.

A family of local bee, Apis mellifera Sp. L., reared in a reconstructed beehive for rearement of family with two queens was used. Bee venom was obtained trough electrostimulation twice a month from 11.03 to 17.10 1998 from 10.00 am to 1.00 pm by the scheme 30 min stimulation, 60 min pause, 30 min stimulation. The effect of entrance orientation was determined by locating the collectors of electrostimulator at the same time on the two entrances oriented East-West. Mass of the obtained bee venom was determined by torsion scale with accuracy of 0.001 g. It was found that year yield of bee venom from a bee family for 15 seances on 14 days interval from 11.03 to 17.10 was 3.804 g. The maximum quantity of bee venom was received in June and July, and the smallest one - in March and October. Orientation of entrance did not influence on the amount of obtained bee venom. On the wall of collector turned against the bees exiting beehive entrance was deposited 63.7-63.9% from the obtained bee venom.

The extent of development of hypopharyngeal glands of nurse bees (after Maurizio, 1954, in points) set at different rearement conditions: without restrictions, with particular removing of pollen and at absence of pollen in the bee nests. For supplementary feeding (spring and autumn) was used honey-sugar paste containing 10% and 30% pollen substitute (raw protein content 25%). Supplementary feeding with 30% pollen substitute at presence of pollen in the bee nests was with clearly expressed positive effect despite of season. Relatively good development of hypopharyngeal glands of bees was found (2.63 points) at autumn supplementary feeding with 30% pollen substitute and absence of pollen, that presupposed successful utilization of the substitute at the end of bee-keeping season before wintering.

Effect of stimulator Intersim and its components on bees and bee families were studied. Different doses of preparation (0.1%, 0.5% and 1.0%) were tested, added as sugar solution (1:1). Changes in bee families development (strength - kg, quantity of reared brood - number of cells with sealed brood, live weight of queen - mg) and total protein and lysozyme in hemolymph content of nurse bees were traced. Higher values of lysozyme activity and total protein quantity in the hemolymph were accounted for bees that have received Interstim. Addition of stimulator increased the live weight of queens and respectively their reproductive abilities.

The purpose of this study was to examine the ability of type I- (porcine pancreas and Naja mocambique mocambique venom), type II-(bothropstoxin-I, bothropstoxin-II, and piratoxin-I), and type III- (Apis mellifera venom) secretory phospholipases A2 (sPLA2s) to induce human neutrophil chemotaxis, and the role of the cell surface proteoglycans, leukotriene B4 (LTB4), and platelet-activating factor (PAF), in mediating this migration. The neutrophil chemotaxis assays were performed by using a 48-well microchemotaxis chamber. Piratoxin-I, bothropstoxin-I, N. m. mocambique venom PLA2 (10-1000 mug/mL each), bothropstoxin-II (30-1000 mug/mL), porcine pancreas PLA2 (0.3-30 mug/mL), and A. mellifera venom PLA2 (30-300 mug/mL) caused concentration-dependent neutrophil chemotaxis. Heparin (10 -300 U/mL) concentration-dependently inhibited the neutrophil migration induced by piratoxin-I, bothropstoxin-II, and N. m. mocambique and A. mellifera venom PLA2s (100 mug/mL each), but failed to affect the migration induced by porcine pancreas PLA2. Heparan sulfate (300 and 1000 mug/mL) inhibited neutrophil migration induced by piratoxin-I, whereas dermatan sulfate and chondroitin sulfate (30-1000 mug/mL each) had no effect. Heparitinase I and heparinase (300 mU/mL each) inhibited by 41.5 and 47%, respectively, piratoxin-I-induced chemotaxis, whereas heparitinase II and chondroitinase AC failed to affect the chemotaxis. The PAF receptor antagonist WEB 2086 (3-(4-(2-chlorophenyl)-9-methyl-6H -thienol-(3,2-f) (1,2,4)-triazolo-(4,3-a) (1,4)-diazepine-2-yl)-1-(4 -morpholynil)-1-propionate) (0.1-10 muM) and the LTB4 synthesis inhibitor AA-861 (2-(12-hydroxydodeca-5,10-diynyl)-3,5,6-trimethyl-1,4-benzoquinone) (0.1-10 muM) significantly inhibited the piratoxin-I-induced chemotaxis. Piratoxin-I (30-300 mug/mL) caused a concentration-dependent release of LTB4. Our results suggest that neutrophil migration in response to sPLA2s is independent of PLA activity, and involves an interaction of sPLA2s with cell surface heparin/heparan binding sites triggering the release of LTB4 and PAF.

To determine whether and how honeybee (Apis mellifera L.) queens control the proportion of male reproductives, experiments were done with colonies under two nutritional conditions at two seasons. During the reproductive season the proportion of male eggs laid by queens under insufficiently -food-supplied conditions was lower than that under sufficiently-food -supplied conditions. The smaller proportion of male egg production could not be accounted for by cannibalization of male eggs by workers. The workers' allocation to male cell construction did not differ between sufficiently- and insufficiently-food-supplied conditions. During the non -reproductive season, however, queens showed much reduced or nearly no production of male eggs, even if the colonies were sufficiently supplied with food. These results suggest that the honeybee queen adjusts the egg sex ratio by referring to both the nutritional resources and their own intrinsic seasonal factors.

We left pollen traps in two hives at Hinojos (Huelva, Spain) for two days. We removed the pollen loads accumulating on the trays of the trap four times each day and studied their botanical origin. In the two days of sampling, the number of pollen resources and their relative intensity of exploitation varied through the day. Pollen collection was more diverse in the central parts of the day, whereas the use of resources tended to be progressively more uniform through the day.

The bees Apis mellifera, introduced in Brazil in 1956, multiplied quickly and they are present of the north of Argentina to the south of EUA. In that expansion it happened an adaptation process and interaction with the local species. In this work, were observed the behaviour aspects of the recent interaction between the Africanized honey bees and the ants C. atriceps. Field observations showed that this species is a predator of the Africanized honey bees, plundering the honey of the beehives. In laboratory the invasion of the beehives happens after the evening, when there is activity of the ants. The bees do not still present an efficient strategy of defense against those ants, probably for not having had a co -evolution among the two species.

One way in which Apis mellifera honey bees resist Varroa destructor is by detection and elimination of nestmates. This study uses behavioural tests and electroanntennography to assess the role of chemostimuli in recognition by honey bees of this acarian ectoparasite. Behavioural tests using living or dead parasites involved observation of honey bee grooming activity (antennation) under controlled conditions in Petri dishes, and removal behaviour (uncapping and elimination of parasitized and unparasitized control brood cells) under natural conditions. Some bees from colonies with both small and large parasite populations showed aggressive behaviour (biting). No difference was observed according to whether the mite was dead or alive. Under natural conditions, bees uncapped more parasitized cells than control cells. Electroantennographic tests were performed to measure sensitivity to various Varroa extracts at three concentrations (10, 20 and 30 Varroa Equivalents). Only 30 Varroa Equivalent methanol extracts made from Varroa collected from brood cells elicited significantly greater antennal response than controls (pure solvent). All three methanol extracts elicited significantly greater antennal response than controls. No response was observed using Varroa extracts made with acetone or hexane. These findings suggest that polar products may act as chemostimuli for recognition of V. destructor by honey bees. Further study will be necessary to determine which polar products are involved in this recognition and assess grooming and removal behaviour using these products.

Varroa destructor is a parasitic mite of the honey bee species Apis cerana Fabr. and A. mellifera L. Mature females reproduce on the immature stages of their hosts, producing more viable female offspring on drone hosts than on worker hosts. Thus, immature drones are more likely to be infested with mites than immature workers. To investigate the hypothesis that differences in host chemistries underlie the biased distribution of mites between worker and drone brood, the arrestment responses of mites to solvent extracts of a number of stimuli normally encountered by a mite during its life cycle were measured. Mites were arrested by cuticular extracts of worker and drone larvae obtained at 0, 24 and 48 h prior to the time when cell capping is completed. Mites were also arrested by extracts of worker and drone, brood food and cocoons, and by a blend of synthetic fatty acid esters previously shown to be active in the host acquisition process. In a wind tunnel bioassay, mites were attracted to odours from living fifth-instar worker and drone larvae, but not to volatiles from cocoons, brood food or a blend of fatty acid esters. The sex of the host was not an important factor affecting the behavioural responses of the mites in any assay. We conclude that host kairomones play a role in the host acquisition process, but we found no evidence to support the hypothesis that mites use these substances to differentiate between worker and drone brood.

Alphitonia excelsa is a bisexual, protandrous, pioneer rainforest tree. Anthesis and nectar production are diurnal. Populations studied on the Mid -North Coast of New South Wales flower between January and March. Alphitonia excelsa is dependent upon insects for pollen transfer. Flower -visiting insect assemblages are dominated by Hymenoptera, Coleoptera, and especially Diptera but vary over time, and geographically. Most of the visiting insects were 6 mm or less in size. Approximately 200 genera, from 116 families, were recorded from A. excelsa flowers. This fauna comprises taxa that, currently, are known within the region only from A. excelsa, and species shared with other mass-flowering rainforest trees. Aculeate wasps were a conspicuous element of the anthophilous insect fauna visiting A. excelsa in a littoral rainforest remnant at Harrington. Introduced honey bees, Apis mellifera, were active at blossoms at all study sites, but visitation varied over the 3 seasons of study.

It has been shown that honey bees (Apis mellifera L.) adsorb bacterial spores as a function of the electrostatic charge on the bee and concentration of bacteria in the aerosol during tethered flight in wind tunnel experiments. This report presents a mathematical model for predicting the number of spores that could be adsorbed onto free-flying bees passing through a bacterial spore aerosol plume/cloud and experimental validation of this model. The model accounts for the geometry of the aerosol dispersion from a continuous point source, aerosol particle settling, and adsorption and desorption rates onto/off of bees based on laboratory observations of tethered flying honey bees.

We evaluated the resistance to tracheal mites, Acarapis woodi (Rennie) (Acari: Tarsonemidae), of colonies of honey bees, Apis mellifera L. (Hymenoptera: Apidae), headed by daughters of three queens from each of three honey bee stocks: (i) British Columbia "mite-resistant" stock, (ii) Buckfast "mite-resistant" stock, and (iii) Canadian unselected stock. Colonies of all nine families were distributed among four apiaries; half of the colonies in each apiary were treated with formic acid to attempt to control tracheal mites. The study documented significant differences in resistance to tracheal mites among the families of bees, even within each of the three stocks. After the first 4 months of study (by November 1993), differences in mite infestations had developed among the nine families. Formic acid treatments had either short-lived effectiveness (1993) or no effect (1994) on tracheal mite infestations, thereby eliminating the opportunity to evaluate colony performance in the absence of mites. Mite infestations varied significantly among apiary sites. This study highlights the value of evaluating sets of colonies headed by sister queens when identifying mite-resistant stock for breeding purposes.

The biological effect of chitooligosaccharides on the honeybee Apis mellifera L. was studied. It was shown that chitooligosaccharides have a biostimulating effect on the bee, which is expressed in an increase in the bee's life span and a better capacity to withstand extreme temperatures and bacterial infection.

The role of Dufour's gland secretion as an egg discriminator pheromone was reevaluated by simultaneously exposing workers to two combs, one containing queen- or worker-laid eggs and the second containing treated or untreated worker-laid eggs. Treatments included extracts of Dufour's gland secretion as well as the synthetic esters that were identified in the secretion. Policing was clearly detected both in queenright and queen-less colonies by the swift removal of worker, but not of queen eggs. However, neither the glandular secretion nor its synthetic ester constituents were able to protect worker-born eggs from policing. Treated worker eggs were removed significantly faster than queen eggs, and at the same rate as non -treated worker eggs. These results are not consistent with the hypothesis that the secretion serves as an egg-marking pheromone. Chemical analyses of the queen abdominal tips revealed the presence of Dufour's esters, indicating that the glandular secretion oozes out and spreads over the cuticle around the genital chamber. However, contamination while ovipositing may also explain the minute amounts of these esters that were detected on the egg surface. Dufour's gland caste-specific composition suggests that in queens it may constitute a signal that plays a role in queen-worker interactions. Attraction bioassays revealed that the queen secretion, but not that of workers, is very attractive to workers. When applied either on a glass slide or on another worker, a retinue formed around the "surrogate queen". We conclude that Dufour's gland secretion constitutes part of a complex queen signal that is the basis for the social integrity of the honeybee colony.

We examined the interaction of genotype and environment on foraging -behavior development and forage choice in honeybees. High- and low-pollen -hoarding strains and unselected wild-type bees were co-fostered in pairs of colonies manipulated to differentially stimulate high and low pollen foraging. The high-pollen-foraging stimulus consisted of high amounts of larvae, a known stimulus for pollen foraging, plus low amounts of pollen, known to induce pollen foraging. The low-pollen-foraging stimulus consisted of low amounts of larvae plus high amounts of pollen. We estimated the median age at which bees initiated foraging, determined forage choice, and the quality and quantity of resources collected. High -strain bees consistently foraged at younger ages than workers from the other sources. High-strain bees appeared to be more sensitive to the pollen-foraging-stimulus treatments, showing greater differences in foraging age and behavior. Three-way interactions of genotype, pollen foraging stimulus, and colony pair (replicate) were statistically significant for most foraging variables measured suggesting that additional, unknown environmental factors also affect foraging behavior. Our results suggest there is a functional relationship between age of first foraging and forage choice with a strong genetic component that is modulated by colony environment.

Individual and colony-level foraging behaviors were evaluated in response to changes in the quantity or nutritional quality of pollen stored within honeybee (Apis mellifera L.) colonies. Colonies were housed in vertical, three-frame observation hives situated inside a building, with entrances leading to the exterior. Before receiving treatments, all colonies were deprived of pollen for 5 days and pollen foragers were marked. In one treatment group, colony pollen reserves were quantitatively manipulated to a low or high level, either by starving colonies of pollen or by providing them with a fully provisioned frame of pollen composed of mixed species. In another treatment group, pollen reserves were qualitatively manipulated by removing pollen stores from colonies and replacing them with low- or high-protein pollen supplements. After applying treatments, foraging rates were measured four times per day and pollen pellets were collected from experienced by inexperienced foragers to determine their weight, species composition, and protein content. Honeybee colonies responded to decreases in the quantity or quality of pollen reserves by increasing the proportion of pollen foragers in their foraging populations, without increasing the overall foraging rate. Manipulation of pollen stores had no effect on the breadth of floral species collected by colonies, or their preferences for the size of protein content of pollen grains. In addition, treatments had no effect on the weight of pollen loads collected by individual foragers or the number of floral species collected per foraging trip. However, significant changes in foraging behavior were detected in relation to the experience level of foragers. Irrespective of treatment group, inexperienced foragers exerted greater effort by collecting heavier pollen loads and also sampled their floral environment more extensively than experienced foragers. Overall, our results indicate that honeybees respond to deficiencies in the quantity or quality of their pollen reserves by increasing the gross amount of pollen returned to the colony, rather than by specializing in collecting pollen with a greater protein content. Individual pollen foragers appear to be insensitive to the quality of pollen they collect, indicating that colony-level feedback is necessary to regulate the flow of protein to and within the colony. Colonies may respond to changes in the quality of their pollen stores by adjusting the numbers of inexperienced to experienced foragers within their foraging populations.

A melissopalinologycal analysis of Apis mellifera corbicular pollen loads was made in order to determine pollen origin and main pollen sources throughout the bee foraging season in the Delta of the Parana River. This analysis was based on 37 samples from the 1993-1994 beekeeping season. Bees gathered corbicular loads from about 20% of the available species throughout the season, but only 3% of these species were intensely used. The most abundant pollen grains belonged to Asteraceae, Leguminosae, Myrtaceae, Brassicaceae and Salicaceae. The pollen species varied throughout the sampling period. Nutritious quality was generally high. Anemophilous pollen types were harvested when the environmental offer dropped. Cultivated and exotic species heavily contributed at the end of winter and in spring, while native species were preferentially gathered in summer and autumn. The behavior of foraging bees was polylectic, with high pollen diversity in the corbicular loads and plasticity in use of local elements, and selective for the preferential use of lipidic-more energetic -pollen grains.

Apis mellifera scutellata Lepeletier (Hymenoptera: Apidae) extends from South Africa to Ethiopia but includes local populations of varying morphology. The honeybee of Uganda previously represented an important biogeographical gap in defining the population structure of A. m. scutellata, but have now been resolved by morphometric analyses of worker honeybees analysed with multivariate techniques. Honeybees of lower altitudes ( LGT 2000 m) formed one distinct morphocluster typical of A. m. scutellata throughout the continent, while those at higher altitudes ( RGT 2000 m) formed a separate distinct cluster of large, dark bees. The latter occur as an archipelago of mountain ecotypes of A. m. scutellata.

Applying honeybees (Apis mellifera L.) as bioindicators of agroecosystem's contamination by pesticides, it is essential to determine bee mortality in the hive. It is detected weekly using appropriate traps, placed in front of the hive. Comparison between the modified traditional Gary's trap and the "underbasket" trap shows higher efficiency of the last one. This results from its lower sensibility to the variables "time", "year season" and "environment". The variable "time" is intended as the trap's efficiency to gather dead bees in one week (Gary: 76.9%; underbasket: 95.8%). The activity of small saprophages (mostly wasps), which pick up dead or dying bees from the trap, affects the trap's efficiency, in relation to season (Gary: spring 81.9%, summer 85%; underbasket: spring 99%, summer 93.8%) and environmental complexity (Gary: high complexity 75.7%, low complexity 91.2%; underbasket: high complexity 94.6%, low complexity 98.2%). In order to avoid losses of samples and problems related to the impact of atmospheric agents, a new type of trap with closed structure was developed ("barrier trap") that did not affect the hive's activity. The trap is provided with a way-out on the same level of the original hive's exit. The undertaker bees would drop the dead bees in a space which collects them in a sampler. Many modifications were tested, because the results were not completely satisfactory. The best results were gained when the sampler was made of latex (a latex glove).

The red imported fire ant, Solenopsis invicta (Buren), recently infested almond orchards in California by hitchhiking in beehives transported from eastern Texas. This event has stimulated interest in the association between this pestiferous species and the honey bee, Apis mellifera (L.). We here report on ant foraging in and about beehives in an apiary infested with S. invicta. Fire ants located and swarmed most of the baits placed on the ground beside hives, but they did not locate those baits placed on hives. These results were the same in each of three surveys regardless of whether bees were present or absent in hives, and regardless of whether the hives were placed directly on the ground, on palettes, or on stands with the hives inaccessible to ants. All hives inspected internally for S. invicta were also free of the ants. The absence of fire ants in and on beehives suggests that the ants do not normally nest in hives. Hitchhiking may more likely occur when queens or small colonies of fire ants hide in clumps of earth clinging to the palettes used to facilitate moving hives onto trucks with forklifts.

Seven treatments for the control of Varroa destructor (Anderson AMPERSAND Trueman) were tested to determine the optimum timing of miticide application. Threshold mite levels indicating miticide application were determined for three possible treatment dates: April, August, and October. The treatments were as follows: (1) fluvalinate in April, (2) fluvalinate in August, (3) fluvalinate in October, (4) fluvalinate in April and October, (5) fluvalinate applied continuously (except during honey flow) with replacement every 42 d, (6) control (no treatment), and (7) coumaphos in April. The number of miticide applications in a season had no effect on brood area or colony bee population a year after initiating the experiment. However, the absence of any treatment significantly reduced brood area and colony bee population and significantly increased colony mite population. Date of treatment had significant effects on colony mortality rates, mite levels, and brood area the following spring. When coupled with sampling and threshold recommendations, a single, late-season application of fluvalinate is as effective for the control of V. destructor as semiannual or continuous miticide applications. Treatment thresholds were recommended for ether roll and 48-h sticky board sampling methods in April (three and 24 mites, respectively) and August (14 and 46 mites, respectively) and for ether rolls in October (three mites) in cold climates.

The ability to generalize a familiar image to visual transformations like a mirror image or a left-right transformation may allow recognition of familiar images from a different viewpoint. As this problem applies to flower recognition by honeybees, Apis mellifera, we asked whether bees transfer acquired information about a previously rewarded pattern to its mirror image and/or its left-right transformation, and which are the mechanisms involved in such a transfer. Bees were trained either with a single pair of patterns or with six different pairs of patterns presented in a random succession. Within each pair one pattern was rewarded and the other not. All patterns had four quadrants, each displaying a different stripe orientation. In multiple-pattern training the six rewarded patterns shared a common configuration different from that of the six nonrewarded ones. After both kinds of training, the bees preferred the mirror image and the left-right transformation of the rewarded pattern (or rewarded configuration) to a novel pattern. They also preferred the left-right transformation to the mirror image. We explain this performance by: (1) matching with a retinotopic template of the trained patterns after training with a single pair of patterns; and (2) matching with a generalized pattern configuration after training with a randomized series of patterns. In the second case, orientations would be bound together in a specific spatial arrangement. Bees would associate a specific orientation with each retinal quadrant and approach the pattern provided that a particular quadrant contains a particular orientation. Although both strategies are based on comparison of an image currently perceived with one that has to be accessed from memory, they constitute different options as the former is less flexible while the latter allows for categorization of novel patterns.

Background: Up to 20% of patients allergic to Hymenoptera venom are not protected by conventional venom immunotherapy (VIT) with 100 mug of any single venom. Objective: We sought to evaluate the efficacy of an increased venom dose in patients allergic to Hymenoptera venom still reacting systemically to a sting challenge despite immunotherapy with 100 mug of venom every 4 weeks. Methods: In this retrospective study patients were included who still had reacted systemically to a sting challenge with a living bee or wasp despite VIT with a maintenance dose of 100 mug every 4 weeks. The maintenance dose was increased to 150 or 200 mug every 4 weeks, and a second sting challenge was performed. If a patient reacted again, the dose was further increased. Baseline mast-cell tryptase levels were assessed by using a fluoroenzyme immunoassay in stored patient sera. Results: While receiving a maintenance dose of 100 mug of venom every 4 weeks for 7 to 38 months, 18 patients reacted systemically to a bee sting and 22 reacted to a wasp sting. After an increase of the maintenance dose to 150 mug, 2 of 4 patients allergic to bee venom (BV) and 6 of 6 patients allergic to yellow jacket venom (YJV) no longer reacted systemically to the sting challenge. The respective rates of full protection were 13 of 14 and 15 of 16 in patients with an increase of the maintenance dose to 200 mug from the start. Of those 4 individuals not protected by the first dose increase, one patient allergic to BV (prior dose of 150 mug) and one patient allergic to YJV (prior dose of 200 mug) did not react systemically to a further sting challenge while receiving 200 mug of BV or 250 mug of YJV, respectively. One patient allergic to BV who had a systemic reaction to the sting challenge while receiving 150 mug was not protected after a dose increase to 200 mug; she later received a dose of 400 mug of BV, and no further sting challenge was performed. The patient allergic to BV who still reacted systemically after a first dose increase to 200 mug was a female patient with urticaria pigmentosa. She had repeated systemic adverse reactions to further BV immunotherapy, necessitating discontinuation of the treatment; however, she tolerated well VIT with 200 mug of YJV. In all other patients, no unusual adverse reactions to the increased venom doses were observed. Baseline serum tryptase levels were elevated above 13.5 mug/L (95th percentile in normal subjects) in 9 (28.1%) of 32 patients. Conclusions: The majority of patients allergic to Hymenoptera venom who still reacted systemically to a sting challenge despite VIT with a dose of 100 mug every 4 weeks can be fully protected by an increased maintenance dose. This dose increase is well tolerated by most patients. The rather high proportion of patients with elevated baseline serum tryptase levels necessitates further investigation of a possible association between mastocytosis and treatment failure of conventionally dosed VIT.

Habitat fragmentation is thought to lower the viability of tropical trees by disrupting their mutualisms with native pollinators. However, in this study, Dinizia excelsa (Fabaceae), a canopy-emergent tree, was found to thrive in Amazonian pastures and forest fragments even in the absence of native pollinators. Canopy observations indicated that African honeybees (Apis mellifera scutellata) were the predominant floral visitors in fragmented habitats and replaced native insects in isolated pasture trees. Trees in habitat fragments produced, on average, over three times as many seeds as trees in continuous forest, and microsatellite assays of seed arrays showed that genetic diversity was maintained across habitats. A paternity analysis further revealed gene flow over as much as 3.2 km of pasture, the most distant pollination precisely recorded for any plant species. Usually considered only as dangerous exotics, African honeybees have become important pollinators in degraded tropical forests, and may alter the genetic structure of remnant populations through frequent long -distance gene flow.

Reward location behavior of 32 individulas of Apis mellifera ("Honey bee"), 26 Trigona sp. ("Brown Stingless Bee"), and 6 Trigona silvestriana ("Black Stingless Bee") in a patch of 10 Ludwigia peruviana plants was evaluated. Flight distance, time spent on each flower by individual bees and by species, and movement map foraging routes were determined. Apis mellifera is quick collecting pollen while individuals of both Trigona species spend more time on each flower. Competition among the three especies under observation was noticed. Every group of individuals exploited specific parts of the plant patch and they tended to overlap.

An apiary trial was conducted in 1999 in Northern Sardinia (Italy) to evaluate the effectiveness and the persistence of amitraz impregnated in plastic strips against Varroa destructor Anderson and Trueman. Twelve colonies of bees derived from Apis mellifera ligustica Spin. in Dadant Blatt hives were used; six colonies were treated with 2 strips per hive and the other six were left untreated control. Two methods for the evaluation of treatment efficacy were compared: the percent effectiveness measured as the percent reduction of V. destructor infestation in treated hives, and the percent control which took into consideration natural mortality in the control hives. Percent effectiveness was greater than the percent control. Amitraz residues were determined in honey and the plastic strips. No amitraz residue higher than 0.01 mgcntdotkg-1 was detected in honey. The amitraz content was stable during the trial in plastic strips placed in the colonies, and in the control strips. A higher adult bee mortality in the treated hives was recorded only after the first week of the treatment.

Colony mortality and productivity were compared between honey bee (Apis mellifera) colonies infested by zero, one or both species of parasitic mites (Acarapis woodi or Varroa destructor). Mortality, bee and mite populations, sealed brood, and stores were monitored for 16 months, beginning in May. By the following March, 5 out of 6 colonies with both mites were dead, but no other colonies died until September, when 3 out of 4 V. destructor colonies were dead. Dually infested colonies initially had more honey stores, but were dead by March. At that point V. destructor colonies had significantly less worker brood, fewer adult bees and more honey than colonies with no mites or tracheal mites (Acarapis woodi). The colonies with tracheal mites (n=9) and no mites (n=8) did not differ in any productivity parameter measured. These results suggest a synergistic interaction between tracheal and V. destructor mites, treatments against tracheal mites should be applied in dually infested colonies, even if tracheal mites alone are not having an impact.

Honey bee colonies, selected for hygienic behavior on the basis of a freeze -killed brood assay, demonstrated resistance to American foulbrood disease. Over two summers in 1998 and 1999, 18 hygienic and 18 non -hygienic colonies containing instrumentally inseminated queens were challenged with comb sections containing spores of the bacterium Paenibacillus larvae subsp. larvae that causes the disease. The strain of bacterium was demonstrated to be resistant to oxytetracycline antibiotic. Seven (39%) hygienic colonies developed clinical symptoms of the disease but five of these recovered (had no visible symptoms) leaving two colonies (11%) with clinical symptoms. In contrast, 100% of the non-hygienic colonies that were challenged developed clinical symptoms, and only one recovered. All non-hygienic colonies had symptoms of naturally occurring chalkbrood disease (Ascosphaera apis) throughout both summers. In contrast 33% of the hygienic colonies developed clinical symptoms of chalkbrood after they were challenged with American foulbrood, but all recovered. The diseased non-hygienic colonies produced significantly less honey than the hygienic colonies.

The Varroa Treatment Device (VTD) filled with 85% formic acid (FA) was field tested for honey bee parasitic mite control in the Piedmont region of South Carolina from February-October, 1996. Three apiaries with 28 honey bee colonies were used in this test. Each colony was housed and managed in one, 10-frame Langstroth hive body and one 10-frame Illinois super. Two VTD/FA treatments, one Apistan(R) treatment and one control were replicated seven times for comparison of varroa and tracheal mite levels. Treatments were: (1) two 60-day treatments with the VTD/FA; (2) continuous VTD/FA treatment except during the 2-month nectar flow period; (3) two 42-day treatments with Apistan(R); and (4) VTD with sawdust but no FA as a control. Initial treatments were placed in colonies on 19 February, and the second treatments of VTD/FA and Apistan(R) were administered on 6 August. The VTD/FA treated colonies were serviced at approximately two week intervals during the treatment periods. Samples of approximately 300 adult bees were collected for mite diagnosis (alcohol wash method) on 23 January, 11 April, 10 June, 6 August, and 15 October. One hundred pupae from each colony were extracted and checked for varroa on the same dates beginning 11 April. Thirty-three adult bees from each sample were also diagnosed for tracheal mites by the thoracic disc method. Varroa mite counts on adult bees collected from all treatments were significantly less than the control for the August and October samples. Although varroa mite counts on extracted bee pupae from most treatments were significantly less than the control for the August sample, the Apistan(R) treatment was the only treatment that maintained significant varroa control in the brood for the October sample. Although the results of this test indicate that the VTD/FA is less effective than Apistan(R) in controlling varroa mites, the VTD/FA provides a viable alternative varroa mite control in combination with other mite control measures, especially as an early season treatment.

This study demonstrated (1) that honey bees, Apis mellifera L, can express a high level of resistance to Varroa destructor Anderson AMPERSAND Trueman when bees were selected for only one resistant trait (suppression of mite reproduction); and (2) that a significant level of mite-resistance was retained when these queens were free-mated with unselected drones. The test compared the growth of mite populations in colonies of bees that each received one of the following queens: (1) resistant-queens selected for suppression of mite reproduction and artificially inseminated in Baton Rouge with drones from similarly selected stocks; (2) resistantXcontrol -resistant queens, as above, produced and free-mated to unselected drones by one of four commercial queen producers; and (3) control-commercial queens chosen by the same four queen producers and free-mated as above. All colonies started the test with apprxeq0.9 kg of bees that were naturally infested with apprxeq650 mites. Colonies with resistantXcontrol queens ended the 115-d test period with significantly fewer mites than did colonies with control queens. This suggests that beekeepers can derive immediate benefit from mite-resistant queens that have been free-mated to unselected drones. Moreover, the production and distribution of these free -mated queens from many commercial sources may be an effective way to insert beneficial genes into our commercial population of honey bees without losing the genetic diversity and the useful beekeeping characteristics of this population.

The studies were conducted for two years during 1996-1997 and 1997-1998 to evaluate the impact of different waste materials wheat bhusa (chopped wheat straw), paddy straw, sawdust and thermocole sheet (a type of polystyrene board) as inner packing, and in combination with polythene sheets as outer packing, on the brood rearing activity of honeybee (Apis mellifera L.) colonies. The increase in brood area showed that thermocole alone as well as in combination with polythene sheets was superior to all other treatments; followed by paddy straw, wheat bhusa and saw dust, respectively. Considering the economic feasibility and easy availability, the paddy straw packing is recommended for outdoor wintering of honeybee colonies.

Isolating an unknown gene with fine-scale mapping is possible in a 'non -model' organism. Sex determination in honey bees consists of a single locus (sex locus) with several complementary alleles. Diploid females are heterozygous at the sex locus, whereas haploid males arise from unfertilized eggs and are hemizygous. The construction of specific inbred crosses facilitates fine scale mapping in the sex locus region of the honey bee. The high recombination rate in the honey bee reduces the physical distance between markers compared with model organisms and facilitates a novel gene isolation strategy based on step-wise creation of new markers within small physical distances. We show that distances less than 25 kb can be efficiently mapped with a mapping population of only 1000 individuals. The procedure described here will accelerate the mapping, analysis and isolation of honey bee genes.

The NC II mating design of 2 X 4 was made in order to evaluate The combining ability and heterosis of royal jelly yield and quality properties that included royal jelly yield, royal jelly yield per cup, acceptance ratio and acidity in Apis mellifera. The results were as follows: (1) For all characters, general combining ability in six parents (GCA) achieved highly significant level (P LGT 0.01), special combining ability (SCA) only significant (P LGT 0.05), therefore the additive effect is more important for royal jelly yield and quality properties; (2) The GCA of A. m. acervorum in four characters was higher, and the SCA variance of A. m. carpatica, A. m. caucasica was greater, so they were good parents. ZND - 1 Apis mellifera lingustica in royal jelly yield, royal jelly yield per cup, acceptance ratio was an excellent parent, but A. m. carnica only could be used in increasing royal jelly quality; (3) The heterosis over high - parent is negative, thus it is difficult to improve royal jelly yield and quality by cross breeding, but by appropriate choice of parents, high yield and quality combination can be obtained.

The role of honeybees (Apis mellifera) in the pollination of buckwheat cv. Manor was studied in a commercial planting at Smeaton, Victoria. Honeybees comprised 80% of all insect visitors to this crop. Other insects included ladybirds (Coccinella transversalis and C. undecimpunctata), hoverflies (Meangyna viridiceps), drone flies (Eristalis sp.), blowflies (Calliphoridae), cabbage white butterflies (Pieris rapae), small bush flies and native bees. The activity of honeybees and other insects increased seed production from 91.5 g/plot (plots closed to insects) to 180.4 g/plot (plots open to insects).

Reliable retention of olfactory learning following a 1-trial classical conditioning of the proboscis extension reflex (PER) is not achieved in honeybees until they are 6-7 days old. Here we show that treatment of newly emerged honeybees with juvenile hormone (JH) has a profound effect on the maturation of short-term olfactory memory. JH-treated individuals display excellent short-term (1 h) memory of associative learning at times as early as 3 days of age and perform consistently better than untreated bees for at least the first week of their lives. By contrast, the retention of long-term (24 h) memory following a 3-trial conditioning of the PER is not significantly improved in JH-treated bees. Our study also shows that experience and (or) chemosensory activation are not essential to improve learning performance in olfactory tasks. The lack of accelerated development of long-term retention of olfactory memories in JH -treated honeybees is discussed in the context of neural circuits suspected to mediate memory formation and retrieval in the honeybee brain.

We examined the role of nonnative honey bees (Apis mellifera) as pollinators of the invasive, nonnative plant species yellow star-thistle (Centaurea solstitialis), both introduced to the western United States in the early to middle 1800s. Using four different treatments (three exclosure types) at flower heads, we observed visitation rates of different pollinators. Honey bees were the most common visitors at each of three transects established at three study locales in California: University of California at Davis, Cosumnes River Preserve, and Santa Cruz Island. A significant correlation existed between honey bee visitation levels monitored in all these transects and the average number of viable seeds per seed head for the same transects. Selective exclusion of honey bees at flower heads using a 3 mm diameter mesh significantly reduced seed set per seed head at all locales. Seed set depression was less dramatic at the island locale because of high visitation rates by generalist halictid bees Augochlorella pomoniella and Agapostemon texanus that penetrated the 3-mm mesh. The introduced megachilid bee Megachile apicalis occurred at all three locales as well (though in much lower numbers) and may contribute to pollination. In an ancillary study, seed set of plants with bagged heads was compared with that of plants without any bagged heads to test for resource shunting effects. These results showed that seed set differences observed between treatments within a single plant were not exaggerated due to resource shunting induced by the bagging technique. Yellow star-thistle may have low or variable levels of self-compatibility (as reflected by low seed set levels in small-mesh bags), increasing the importance of pollination in its breeding system. These results suggest that honey bees and yellow star-thistle may act as invasive mutualists, an association that may extend to other nonnative plant and pollinator species from Eurasia.

Reward location behavior of 32 individuals of Apis mellifera ("Honey bee"), 26 Trigona sp. ("Brown Stingless Bee"), and 6 Trigona silvestriana ("Black Stingless Bee") in a patch of 10 Ludwigia peruviana plants was evaluated. Flight distance, time spent on each flower by individual bees and by species, and movement map foraging routes were determined. Apis mellifera is quick collecting pollen while individuals of both Trigona species spend more time on each flower. Competition among the three especies under observation was noticed. Every group of individuals exploited specific parts of the plant patch and they tended to overlap.

Infestation of brood by Tropilaelaps chlareae as well as the mite mortality attained two peaks during June-July and October-November in Apis mellifera. Acarapis woodi infestation remained considerably low during March to May and high during October-November in A. mellifera as well as in A. cerana. Strong correlation appeared between acarine infested bees and maximum number of mites per trachea in both the spp. of honeybees. Confinement of bees in the colony either due to rain or cold or the conditions unfavorable to colony development may enhance mite infestation in the colonies.

Traditionally it has been considered that the bees that live in the Iberian Peninsula belong to the iberica race, this one is related with the intermissa race of the north of Africa and the mellifera race of western Europe. The workers bees proceed from Spain and Portugal, they have been described as animals of jet black colour, with hairiness and tomentum of medium size, and a quite long proboscis; some authors that the bees of the south had a shorter hairiness and a longer proboscis finding that those coming from the north. We have studied 34 samples of workers originate from two areas of Iberian peninsula (the south of Spain and the center of Portugal), and of the Archipelago of Madeira, to study the existence of possible morphological differences. The results show that the animals constitute three morphological groups, identifiable by canonical analysis. One of them includes the bees proceeding from the center of Portugal, another is formed by those of Cordoba, and the third are constituted by workers come from Madeira and Cazorla.

The honeybees of the the Iberian Peninsula have been described traditionally as belonging to the iberica race. This race is constituted by animals of dark colour and a great vigor, its behavior is rather nervous and the propensity to swarm is considered as moderate. From a morphological point of view, they are few the works in those that these insects have been studied, including the bibliography descriptions more or less extensive of those that inhabit the mediterranean region, Asturias and the North Submeseta. If we admit that different climatic conditions should have produced selective effects on the insects characteristics, it is very interesting to study bees coming from different localizations, to know the variability. We have studied 16 morphological characteristics in 18 workers bees samples, originating of the center of Portugal and the Madeira island. The results indicate that the bees of Portugal constitute a morphological group, in which big differences are not appreciated among the different geographical localizations. The animals coming from Madeira also form a morphological group. When the bees coming from these two places are studied in a combined way, the canonical analysis shows a partial overlap of the populations.

Background: With the increase in commercial vegetable production in greenhouses, occupational sensitization to bumblebee venom is becoming more common. Studies using sera from subjects thus sensitized allow evaluation of the allergenic specificity of bumblebee sensitization. Objective: The purposes of this study were to determine the degree of species group specificity of bumblebee venom allergens in sera of allergic patients and to investigate the structural basis of this specificity. Methods: Allergens were purified from bumblebee venom, studied serologically by direct binding and inhibition techniques, and characterized by enzyme analysis and amino acid sequencing. Three -dimensional models of the phospholipases were constructed and analyzed. Results: Bombus terrestris venom contains phospholipase A2, venom protease, hyaluronidase, and acid phosphatase allergens. The protease and phospholipase A2 allergens contain IgE-reactive epitopes that are different from those seen in Bombus pennsylvanicus, a North American species. Bumblebee phospholipase A2 is only 53% identical to honeybee phospholipase A2. The results of 3-dimensional modeling are consistent with the immunologic observations. Conclusions: Patients with primary bumblebee sensitization should be diagnosed and treated with venom from the appropriate species group of bumblebees. Bumblebee venom phospholipase A2 and protease are antigenically distinct from honeybee venom proteins. There are significant species group-specific epitopes on bumblebee venom proteins.

The epidermal proteins from staged Apis mellifera pupae and pharate adults and the progress of cuticular pigmentation until adult eclosion were used as parameters to study integument differentiation under hormonal treatment. Groups of bees were treated at the beginning of the pupal stage with the juvenile hormone analog pyriproxyfen (PPN) or as pharate adults with 20-hydroxyecdysone (20E). Another group was treated with both hormones applied successively at these same developmental periods. Controls were maintained without treatment. The epidermal proteins, separated by SDS-PAGE and identified by silver staining, were studied at seven intervals during the pupal and pharate adult stages. The initiation and progress of cuticular pigmentation was also monitored and compared to controls. The results showed that PPN reduced the interval of expression of some epidermal proteins, whereas 20E had an antagonistic effect, promoting a prolongation in the time of expression of the same proteins. In PPN-treated bees, cuticular pigmentation started precociously, whereas in 20E-treated individuals this developmental event was postponed. The double hormonal treatment restored the normal progress of cuticular pigmentation and, to a large extent, the temporal epidermal protein pattern. These results are discussed in relation to the 20E titer modulation and morphogenetic hormone interaction.

Bumblebees and honeybees deposit short-lived scent marks on flowers that they visit when foraging. Conspecifics use these marks to distinguish those flowers that have recently been emptied and, so, avoid them. The aim of this study was to assess how widespread this behavior is. Evidence for direct detection of reward levels was found in two bee species: Agapostemon nasutus was able to detect directly pollen availability in flowers with exposed anthers, while Apis mellifera appeared to be able to detect nectar levels of tubular flowers. A third species, Trigona fulviventris, avoided flowers that had recently been visited by conspecifies, regardless of reward levels, probably by using scent marks. Three further bee/flower systems were examined in which there was no detectable discrimination among flowers. We argue that bees probably rely on direct detection of rewards where this is allowed by the structure of the flower and on scent marks when feeding on flowers where the rewards are hidden. However, discrimination does not always occur. We suggest that discrimination may not always make economic sense; when visiting flowers with a low handling time, or flowers that are scarce, it may be more efficient to visit every flower that is encountered.

Foraging decisions are based on a suite of choices that include energetics and physiological constraints. Although travelling farther to harvest a greater net energetic reward is beneficial, many animals opt for a smaller net reward that requires less travel. Recent discoveries of a visual basis for flower constancy in the honeybee, Apis mellifera, led us to examine older reports that colour cues are superceded by energetic considerations. Here we show that when individual bees foraged on pedicellate artificial flowers varying in colour and interfloral distance, their behaviour depended on the colours in the choice test. Colours of similar spectral reflectance (blue versus white), that would be clustered in the bee's visual colour space, elicited more visits to the closest flower when rewards were equal, but individuals travelled a greater distance to harvest a higher energetic reward when reward quality varied. Bees chose the closest flower more often when reward volume decreased while quality remained constant. Yet, even when all flowers were identical (morphology and reward), and only interfloral distance varied, bees did not always visit the closest flower. A dramatic difference was seen when the dimorphism was yellow-blue, colours quite separate in the bee colour space and known to elicit constancy behaviour. Here, bees visited the closest flower only 5% of the time, and varying reward volume did not elicit different behaviour. Animals thus display differential foraging behaviour with respect to environmental cues that must be considered when asking questions about other behavioural parameters.

We determined whether defense by individual bees against non-nestmates in honey bees (Apis mellifera) is correlated with their juvenile hormone (JH) titers, which are known to vary developmentally and seasonally. We bioassayed winter and summer bees for aggressive and non-aggressive individuals. Bees in winter could not be distinguished by task group, but bees in summer were segregated into nurses and guards. JH titers were correlated with aggressive behavior at two levels. First, winter bees and summer nurses, known to have lower JH titers, both showed less aggression toward foreign bees than did summer guards. Second, aggressive individuals had significantly higher JH titers than did non-aggressive bees within each colony. Inter-colonial variation in aggressiveness was maintained during summer and winter, suggesting a genetic basis for these differences. An alarm pheromone test further substantiated the existence of inter-colonial differences. We found significant variation in JH titers among different colonies, but the variation was not significantly associated with colony-level aggressiveness. The correlation between JH and levels of aggressiveness within a colony suggests a regulatory role for JH, but variation among colonies involves factors other than JH.

The maximum number of bees (9.79 bees/minute/5 capitulum) visited the flowers of sunflower for collection of nectar or pollen or both at nearer distance (10 m) whereas minimum (5.32 bees/minute/5 capitulum) at the farthest distance (500 m) from apiary. The number of filled seed per capitulum decreased as the distance of target crop from apiary increased being maximum (680.9) at 10 m and minimum (457.7) at 500 m. The thousand seed weight was also significantly highest (58.7 g) at the closer distance (10 m) while lowest (40.3 g) at the farthest distance (500 m) from apiary. The seed obtained from farthest distance had less germination (70.75%) as compared to seeds obtained at nearest distance (83.50%).

The reproductive behaviour of the mite Varroa jacobsoni was investigated during the summer months in Apis mellifera syriaca colonies in Irbid, Jordan. Reproductive rates for mites reaching adulthood were estimated by examining the progeny of the female mother mites in worker and drone cells. The proportions of non-reproducing mites in the worker and drone brood were 9.8% and 4.9%, respectively. The reproductive rate was 2.72 for mites in worker cells and 3.35 for mites in drone cells. The percentage of infested brood with adult mite daughters was 43.9% for worker and 55% for drone broods. The rate for females reaching adulthood from each original female mite was 0.75 for worker and 1.41 for drone brood.

We constructed a linkage map of Bombus terrestris (Hymenoptera, Apidae) phase unknown. The map contains 79 markers (six microsatellite and 73 RAPD markers) in 21 linkage groups and spans over 953.1 cM. The minimal recombinational size of the B. terrestris genome was estimated to be 1073 cM. Using flow cytometry, the physical size of the haploid genome of B. terrestris was calculated to be 274 Mb. This is the second linkage map for a social insect species. Bombus terrestris has on average five times less recombinational events per kb than the honey bee Apis mellifera. Male haploidy, chromosome size, and eusociality can now be excluded as reasons for the high recombination frequency of Apis mellifera. Finally, the sex determination locus of B. terrestris was placed on the map using bulked segregant analysis.

This meeting contains abstracts of 36 papers, each written in English, French and German versions, covering topics in apidology, including bee products, foraging, honey components analysis, pest population dynamics, chemical pest control, bioindicators, plant protection, pathologies including varroosis, American foulbrood, physiology, behavior, breeding, genetics, selection, and beekeeping practices.

We report our progress in understanding the structure-function relationship of the interaction between protein inhibitors and several serine proteases. Recently, we have determined high resolution solution structures of two inhibitors Apis mellifera chymotrypsin inhibitor-1 (AMCI -I) and Linum usitatissimum trypsin inhibitor (LUTI) in the free state and an ultra high resolution X-ray structure of BPTI. All three inhibitors, despite totally different scaffolds, contain a solvent exposed loop of similar conformation which is highly complementary to the enzyme active site. Isothermal calorimetry data show that the interaction between wild type BPTI and chymotrypsin is entropy driven and that the enthalpy component opposes complex formation. Our research is focused on extensive mutagenesis of the four positions from the protease binding loop of BPTI: P1, P1', P3, and P4. We mutated these residues to different amino acids and the variants were characterized by determination of the association constants, stability parameters and crystal structures of protease -inhibitor complexes. Accommodation of the P1 residue in the S1 pocket of four proteases: chymotrypsin, trypsin, neutrophil elastase and cathepsin G was probed with 18 P1 variants. High resolution X-ray structures of ten complexes between bovine trypsin and P1 variants of BPTI have been determined and compared with the cognate P1 Lys side chain. Mutations of the wild type Ala16 (P1') to larger side chains always caused a drop of the association constant. According to the crystal structure of the Leu16 BPTI-trypsin complex, introduction of the larger residue at the P1' position leads to steric conflicts in the vicinity of the mutation. Finally, mutations at the P4 site allowed an improvement of the association with several serine proteases involved in blood clotting. Conversely, introduction of Ser, Val, and Phe in place of Gly12 (P4) had invariably a destabilizing effect on the complex with these proteases.

The aim of the present work is to study the chemical composition of Turkish propolis. Propolis samples were collected from different regions of Turkey (Bursa, Erzurum-Askale, Gumushane-Sogutagil and Trabzon-Caglayan) in 1999. Ethanol extracts of propolis (EEP) were prepared for chemical analysis, using gas chromatograph coupled with mass spectrometry (GC-MS). Our findings show that propolis samples from Trabzon and Gumushane region have a similar chemical composition. In both samples aromatic acids, aliphatic acids and their esters, and also ketone derivatives are the main compound groups. The chemical composition of the single sample that was collected from Erzurum region shows a very different pattern than the other two samples. In this propolis, the main compounds are aromatic acid esters and alcohols. However, it contains a high amount of amino acids compared to the other samples. The other samples collected from three different region of Bursa City are rich with flavavones, aromatic acids and their esters, terpenoids, flavones and ketones.

Since nectar constitutes a highly variable resource, forager honeybees (Apis mellifera) always adjust their social foraging activities according to the current profitability of the nectar sources they exploit. If trophallaxis, food exchange among individuals of the same colony, serves to improve the coordination among nectar foragers, as occurs with the dance behavior, a high correlation might be expected between the foragers' trophallactic behavior and the profitability of the food sources they exploited. The aim of this work was to analyze whether a forager bee changes her trophallactic behavior with the varying profitability of a food source. In addition, since food source profitability affects dance behavior, we also analyzed the degree of coupling between the trophallactic and dance behavior of returning honeybees. Results show that trophallaxis by forager bees inside the hive changed rapidly with fluctuations in food source profitability. After an increase in profitability, returning foragers (1) increased the number of trophallactic offering contacts, (2) decreased the average duration of offering contacts, (3) shifted the temporal distribution of offering contacts from being mainly near the beginning of the time in the hive to being more evenly distributed throughout the entire visit, (4) begged for food less frequently, and (5) shifted their begging toward the very end of the visit. Regarding their dance behavior, foragers danced earlier in their visits to the hive and performed more waggle runs when the profitability of the food source was increased. Furthermore, the trophallactic and dance behaviors were affected not only by the absolute profitability of the food source but also by changes in profitability. Taken together, these results indicate that, in addition to dance behavior, short trophallactic interactions of returning foragers (which include both offering and begging contacts) may help foragers to communicate information about rapidly fluctuating resource opportunities.

Honey bee nest entrance guards accepted a significantly lower proportion of non-nestmates of a different subspecies (5%) than non-nestmates of their own subspecies (18%). This result was consistent for 5 of the 6 study colonies (the sixth rejected all non-nestmates), 3 each of Apis mellifera mellifera and A.m. ligustica, and for each subspecies of guards (A.m.m. 5% v 17%; A.m.l. 4% v 20%). These data indicate that there are consistent recognition cue differences across subspecies.

Honeybees (Apis mellifera L.) were collected from 23 localities on the Balearic islands in the Mediterranean Sea. The mitochondrial genome (mtDNA) was surveyed for diagnostic restriction sites and characterized with DraI digestion of the tRNAleu-COII intergenic region. Both approaches demonstrated that honeybees bearing either African or west European haplotypes coexist on the Balearic islands. Two African and two west European haplotypes were found with different frequencies and distribution among the islands. Phylogenetic and population structure analyses support the clustering of these islands in two groups: Majorca-Minorca (Gymnesic) and Ibiza-Formentera (Pityusic) what corroborates the current biogeographical division of the Balearic organisms. These results partially agree with the observed distribution of African haplotypes in honeybee populations from other Mediterranean islands. The present distribution of genetic markers may reflect also the influence of human movements, trade and settlements from prehistoric times.

Two new and seven known compounds, including terpenoids and aromatic compounds, were isolated from the essential oil of Brazilian propolis. The structures of the new compounds were elucidated as 2,2-dimethyl-8-prenyl-6 -vinylchromene (1) and 2,6-diprenyl-4-vinylphenol (2) on the basis of spectroscopic analyses.

Two bioassays were administered to determine the dose-lethality response of Varroa jacobsoni Oudemans and the honey bee, Apis mellifera L., to amitraz, flumethrin and fluvalinate. The first bioassay method was spraying by means of the Potter-Bourgerjon's tower. The results are expressed in mean lethal concentrations (LC50). The second method was topical application by means of microsyringe and manual applicator. The results are expressed in mean lethal doses (LD50). Both LC50 and LD50 values were considerably higher in honey bees than in varroa mites, showing that a wide margin of safety exists between effective doses against mites and harmful doses for honey bees. Both methods gave similar confidence intervals; they showed a comparable sensitivity to changes in dose or concentration of pesticides.

1. The ecto-parasitic mite Varroa destructor is a serious world-wide pest of the honeybee Apis mellifera and has being linked with the death of millions of colonies, although its role in colony death has remained elusive. 2. A simulation model was developed to explain the link between the mite and collapse of the host bee colony, given that colony death does not always occur. We investigated the effects of two pathogens, deformed wing virus (DWV) and acute paralysis virus (APV), vectored by the mite, on the host colony. 3. Two previously published simulation models, a bee and a mite, were combined and adapted for use in temperate climates with a variety of bee diseases. The model was constructed using Modelmaker(R) software, which allows the progression of a disease in the host colony to be followed daily. 4. The population dynamics generated by the model were similar to those observed in a natural honeybee colony. When DWV- or APV -transmitting mites were introduced into the colony, its adult worker bee population collapsed either during winter or spring for DWV, or autumn to spring for APV. This corresponds well with field observations of colony death in Europe. 5. The model revealed that DWV initially had little effect on the colony but during late summer, as the population of DWV -transmitting mites increased, the virus caused a reduction in the number of healthy young bees entering the overwintering population. This imbalance in the age structure of the overwintering bees resulted in the eventual death of the colony during the winter or spring. As few as 2000 -3600 mites in autumn could kill a colony. 6. In contrast, APV transmitted by Varroa was only able to kill the honeybee colony if a large (10 000+) mite population was already present when an overt APV infection occurred. It was difficult for APV to become established within the bee population due to it causing rapid host death. 7. The model predicts that the less virulent DWV will become more widely established than the highly virulent APV, and that mite control measures need to be taken prior to the production of overwintering bees.

Honeybees (Apis mellifera) can be trained to associate an odor stimulus with a sucrose reward. The neural structures involved in the detection and integration of olfactory stimuli are represented bilaterally in the brain. Little is known about the respective roles of the two sides of the brain in olfactory learning. Does each side: learn independently of the other, or do they communicate, and if so, to what extent and at what level of neural integration? We addressed these questions using the proboscis extension response (PER) conditioning paradigm applied in a preparation that allows the separation of the two input sides during olfactory stimulations. Bees conditioned to two odorants A and B, one being learned on each side (A+/B+ training), showed in extinction tests rather unspecific responses: They responded to both odorants on both sides. This could be attributable to either a transfer of the learned information between sides, or to a generalization between odorants on each side. By subjecting bees to conditioning on one side only (A+/0 training), we found that the learned information is indeed transferred between sides. However, when bees were trained explicitly to give opposite values to the two odorants on the two sides (A+B-/B+A- training), they showed clear side -specific response patterns to these odorants. These results are used in the elaboration of a functional model of laterality of olfactory learning and memory processing in the honeybee brain.

Whereas in several parts of the world varroa is the major pest affecting apiculture, in others the parasite is unknown to many beekeepers because of the little damage it causes to bees. The impact of the mite Varroa jacobsoni is related to the climatic conditions and the races of Apis mellifera bees in each region where the pest exists. In the present study, the mite infestation levels were assessed to determine the evolution of the pest in Africanized bee colonies in Southern Brazil. The current level of infesiatton was considered low, approximately two mites per one hundred adult bees. This result is similar to that obtained for the same apiary almost five years ago and for others distributed in various regions of Brazil. In the present study, on average, 61% of the total varroa population was found in the worker brood.

1. To help evaluate the worth of alternative pollinators in agriculture, we present a theoretical framework for comparing the effectiveness of two or more pollinators by measuring pollen removal and deposition. 2. We report pollen removal and deposition data by Apis mellifera and Bombus spp. during single visits to four cultivars of apples (Golden Delicious, Starkrimson Delicious, Empire/MacIntosh and Rome) and Mission almond. 3. Apis and Bombus removed similar amounts of pollen from apple flowers but Bombus deposited more pollen on stigmas. Pollen-collecting bees removed more pollen from apple anthers than nectar-collecting bees. Apis that approached nectaries laterally deposited substantially less pollen than other visitors. 4. Apis and Bombus removed and deposited similar amounts of pollen on almond flowers. Apis tended to remove more during pollen -collecting visits than nectar-collecting visits. The type of resource sought did not significantly influence deposition. 5. Based on removal and deposition data, additions of Bombus may increase pollen delivery in apple orchards but reduce pollen delivery in almond orchards if Apis already serve as primary pollinators. Additional data on inter-tree and inter-row flights would be necessary to know how much these changes in pollen transfer might affect fertilization. 6. Measures of pollen-transfer effectiveness do not provide a complete assessment of pollination value, but can serve as a general, inexpensive tool for pre-screening possible alternative pollinators.

A study was conducted to identify quantitative trait loci (QTLs) that affect learning in honeybees. Two F1 supersister queens were produced from a cross between two established lines that had been selected for differences in the speed at which they reverse a learned discrimination between odors. Different families of haploid drones from two of these F1 queens were evaluated for two kinds of learning performance-reversal learning and latent inhibition-which previously showed correlated selection responses. Random amplified polymorphic DNA markers were scored from recombinant, haploid drone progeny that showed extreme manifestations of learning performance. Composite interval mapping procedures identified two QTLs for reversal learning (lrn2 and lrn3: LOD, 2.45 and 2.75, respectively) and one major QTL for latent inhibition (lrn1: LOD, 6.15). The QTL for latent inhibition did not map to either of the linkage groups that were associated with reversal learning. Identification of specific genes responsible for these kinds of QTL associations will open up new windows for better understanding of genes involved in learning and memory.

A newly developed method for measuring the integrated esterase inhibiting potency of rainwater samples was applied in practice, and the results are compared to the toxic potency calculated from concentrations of 31 organophosphate (OP) and carbamate pesticides, out of a total of 66 chemically analyzed pesticides. In addition, the general toxic potency of the rainwater samples was evaluated in a microtiter luminescence assay with Vibrio fischeri bacteria. Rainwater samples were collected over four consecutive 14-day periods in both open and wet-only samplers. The esterase inhibiting potency of the open rainwater samples (expressed as ng dichlorvos-equivalents/l) corresponded well with the chemical analyses of the rainwater samples collected by both types of samplers (r=0.83-0.86). By far, the highest esterase inhibiting potency was found in a sample collected in an area with intense horticultural activities in June, and was attributed to high concentrations of dichlorvos, mevinphos, pirimiphos -methyl and methiocarb. The esterase inhibiting potency of this sample was equivalent to a dichlorvos concentration of 1380 ng/l in the rainwater, which is almost 2000 times higher than the maximum permissible concentration (MPC) of dichlorvos set for surface water in Netherlands. Maximum individual concentrations of dichlorvos and pirimiphos-methyl even exceeded the EC50 for Daphnia, suggesting that pesticides in rainwater pose a risk for aquatic organisms. Not all responses of the luminescence -assay for general toxicity could be explained by the analyzed pesticide concentrations. The bio-assays enable a direct assessment the toxic potency of all individual compounds present in the complex mixture of rainwater pollutants, even if they are unknown or present at concentrations below the detection limit. Therefore, they are valuable tools for prescreening and hazard characterization purposes.

Merostachys riedeliana Rupr. is a long-lived monocarp species common in the understorey of tropical semideciduous forest fragments in the south of Minas Gerais, Brazil. Its floral biology and breeding system were studied and compared with others bamboos. Due to its rhizome, it occurs in clumps and has a remarkable capacity for vegetative multiplication, which ceases a few months before the emergence of the first inflorescences. The beginning of the flowering and the death of the entire population occurred respectively on October 1998 and May 1999. The peak of the blooming episode took place during the hot and rainy months of the year (December and January). Each inflorescence produces in average 29 spikelets, which have hermaphrodite florets with three stamens and two plumose stigmas that are exposed during the anthesis. The abundant pollen is easily released by the wind or visitors. Apis mellifera L. and Trigona spinipes (F.) were the commonest visitors and behave as pollen thieves. These bees occasionally act as devices for dispersion of pollen, through vibration produced in the anthers. The excess of rain during flowering and the lack of wind in the understorey of the forest constrain the effectiveness of the anemophily. However, several morphological characters of the flowers, leaf fall and dense clumps tend to expect for wind pollination. Also, the auto -incompatibility index (0.99) showed that M. riedeliana is an autocompatible bamboo. So the auto-incompatibility does not favour the formation of fruits in vegetal clones, and the autocompatibility could result in the high production of seeds. Therefore the possible occurrence of clones of M. riedeliana in the forest fragments, due to the effective vegetative growth and the 30-32 years cyclic flowering intervals, might explain the high investment on spikelets production and autocompatible fruits formation.

The reproductive biology and pollination of three species of the genus Combretum were studied in natural populations, in areas of Caatinga (C. leprosum Mart. and C. pisonioides Taub.) and Atlantic forest (C. fruticosum (Loefl.) Stuntz) in Pernambuco and Paraiba states, northeastern Brazil. All the species presented continuous flowering after the rainy season. The colors of the flowers change during the anthesis period. Sugar concentration in the nectar is about 20.9% (sd=2.08) in C. pisonioides, 21.3% (sd=2.97) in C. leprosum and 9.6% (sd=0.86) in C. fruticosum. The three species are self-incompatible. Pollen viability is higher than 95%. The flowers of C. pisonioides and C. leprosum have mellittophilous attributes. C. pisonioides is pollinated by wasps of the genus Polybia. C. leprosum is pollinated by ca. 20 species of Hymenoptera and Lepidoptera. Apis mellifera (Apidae) was the most frequent visitor to the flowers of this species. C. fruticosum is ornithophilous, pollinated by passerine birds (Coerebidae) and hummingbirds (Chlorostilbon aureoventris).

One-day-old anarchistic (selected for successful worker reproduction) and wild-type honey-bee workers were introduced into queenright colonies of honey-bees of two treatments. In treatment 1, all eggs and larvae were offspring of queens from an anarchistic line. In treatment 2, all eggs and larvae were offspring of wild-type queens. In both treatments, adult workers were wild type. This experimental arrangement was used to test the importance of larval genotype on ovary activation in young adult workers. After 12 days, the introduced bees were dissected to determine the frequency of ovary activation. In those colonies provided with wild-type brood, 0% of introduced wild-type bees and 16% of anarchistic bees had activated ovaries. In those colonies provided with anarchistic brood, 13% of introduced wild-type bees and 41% of anarchistic bees had activated ovaries. These results strongly support the hypothesis that selection for high levels of worker reproduction in anarchistic stocks has reduced the amount or composition of brood pheromones produced by larvae that normally signal workers to refrain from reproduction. They also suggest that anarchistic workers have a higher threshold for these signals than wild -type bees.

Frequencies are reported for restriction fragment-length polymorphisms (RFLPs) at a highly polymorphic nuclear locus in Old and New World honey bee populations. The distribution of these (RFLPs) alleles (composed of MspI and DdeI variants) had been found previously to be discontinuous among groups of Old World honey bee subspecies, which included A. mellifera mellifera L. (west European), A. m. ligustica Spinola, A. m. caucasica Gorbachev (east European), and A. m. scutellata Lepeletier (African). In this study, ancestry in New World bees was inferred from allele identities and frequencies at this locus in combination with mitochondrial DNA types. In bees from the United States, collected before the invasion of African bees, east and west European alleles were found at frequencies of 83 and 17%, respectively, which is consistent with previously identified nuclear and mitochondrial DNA markers. Colonies from two neotropical countries, Mexico and Honduras, had African mitochondrial DNA and high frequencies of African nuclear DNA alleles. Consistent with previous findings, east European alleles were absent or detected at low frequencies in these colonies. However, west European alleles were found at frequencies from 26 to 31%. These results suggest that queen offspring of the African queens first introduced into Brazil mated with west European drones, incorporating neutral markers that have since remained in the expanding population of feral African bees. The results point to little paternal introgression from managed east European colonies encountered by the African bees spreading through the neotropics.

The presence of the endoparasitoid fly of the honeybees Senotainia tricuspis (Meigen) in Latium was investigated during 1997-99. The research, carried out on the experimental apiaries, concerned all the 5 provinces with 28 stationings distributed in littoral and inland zones. The presence of S. tricuspis has been evidenced in all the apiaries situated in littoral areas with considerably higher percentages than the inland ones, in some of these the parasitoid fly has turned out absent. The results indicate that S. tricuspis prefers sunny places with sandy land, more suitable for the puping and the wintering of the larvae. The use of white cromotropic traps soaked in glue, arranged on the roof of the beehives, allows to keep the diptera population under the level of economic damage.

Female mites of the genus Varroa reproduce on the immature stages of Apis cerana F. and A. mellifera L. Mites are found more often in drone brood than worker brood, and while evolutionary explanations for this bias are well supported, the proximate mechanisms are not known. In one experiment, we verified that the proportion of hosts with one or more mites (MPV, mite prevalence value) was significantly greater for drones (0.763 +- 0.043) (lsmean +- SE) than for workers (0.253 +- 0.043) in populations of mites and bees in the United States. Similar results were found for the average number of mites per host. In a second experiment, using a cross-fostering technique in which worker and drone larvae were reared in both worker and drone cells, we found that cell type, larval sex, colony and all interactions affected the level of mites on a host. Mite prevalence values were greatest in drone larvae reared in drone cells (0.907 +- 0.025), followed by drone larvae reared in worker cells (0.751 +- 0.025), worker larvae reared in worker cells (0.499 +- 0.025), and worker larvae reared in drone cells (0.383 +- 0.025). Similar results were found for the average number of mites per host. Our data show that mite levels are affected by environmental factors (cell type), by factors intrinsic to the host (sex), and by interactions these factors. In addition, colony-to -colony variation is important to the expression of intrinsic and environmental factors.

The reproductive behaviour of female Varroa destructor mites invading worker brood cells during the winter months (January to mid-March) was investigated in four Apis mellifera colonies in UK. The number of viable offspring produced during a reproductive cycle, per mite, was only 0.5 during winter compared with 1.0 during the summer. This was mainly due to a large increase in the population of non-reproductive mites (winter 20%, summer 8%). This increase can be explained by the high level of male offspring mortality observed in winter (42% vs. 18% in summer), which results in nearly half of the newly reared female mites being unfertilised. Since mites that do reproduce lay a similar number of eggs in winter (X=4.7) as in summer (X=4.9), and the level of mortality suffered by the first female offspring is similar in winter (7%) as in summer (6%), it is probably not the internal physiological state of the host which causes the high level of winter non-reproduction, as has been previously suspected.

Conflict is rare among the members of a highly cooperative society such as a honey bee colony. However, conflict within a colony increases drastically during colony reproduction ('swarming') when newly produced queens fight each other until only one queen remains in the nest. This study describes the behavior of queens and workers during naturally occurring queen combat. The duels of five pairs of queens were observed in three observation colonies. A typical duel is described qualitatively and the events of all five duels are described quantitatively. Several aspects of duels that are of particular interest are examined in detail, including the behavior of queens near capped queen cells, worker aggression toward queens, queen tooting, and the relation of queen and worker behavior to the outcome of the duel. The results of this investigation serve as a foundation for rigorous tests of hypotheses regarding the adaptive significance of queen and worker behavior during queen combat. The results presented suggest that: young queens patrol queen cells to kill rival queens while they are vulnerable; workers aggress queens to prevent them from destroying queen cells; queens toot to inhibit worker aggression; workers immobilize queens to make them easy targets for rival queens; and queens eject hind-gut contents to cause their rival to be immobilized by the workers.

This experiment used screen house and net exclusion methods to measure the effect of honeybee pollination on the yield and fruit quality of strawberry variety 'Toyonoka'. During January and February, the introduction of honeybee colony into the screen house significantly increased the number of fruit sets, but significantly yield increase only occurred in February. In the open strawberry field, among the foragers on flowers, the number of Apis cerana was 4.5 fold that of Apis mellifera, indicating that A. cerana is the major pollinator on strawberries in the Tahu area of Miaoli County. The pollinating activity mainly occurred between 11:00 and 13:30. Open pollination significantly increased the rates of developed achenes and fruit weight as compared with the isolating cages. The results from December to January showed that the percentages of the super and the first grade fruits of the open plots were higher than those of the caged plots. Average daily yields of the super and the first grade fruits of the open plots were 2 times those of the caged plots. The fruit weight was linearly related to the number of developed achenes (Y=0.06X+3.06, R2=0.70), but not to the rate of developed achenes on fruit.

In a two years' field trial, seeds of sunflower (Helianthus annuus L.) hybrid LSH-3 were produced either through open or hand (daily pollination as soon as ray florets start appearing, pollination on alternate and interval of two and three days) pollination. The hybrid seed so obtained from different treatments of two pollination modes/techniques were assayed for different morpho-physiological attributes of seed viz., total number and weight (g) of seeds per capitulum (filled and unfilled), 100-seed weight (g), standard germination, abnormal seedlings and seedling vigour index at 70 and 140 days after harvest. Irrespective of honeybee species (Apis dorsata and A. mellifera), their abundance on seed parent varied from 0.54 (at 14h00) to 1.43 (at 18h00) per capitulum per minute in open pollinated crop. Pollination modes had significant effects on the number and weight (g) of total, filled and unfilled seeds per capitulum and also 100-seed weight (g). Open pollination of seed parent with natural honeybee populations resulted not only in higher hybrid seed yields but also its quality was better than the hybrid seed obtained with other pollination modes. Hybrid seeds obtained with daily hand pollination had germination (66.8%) below the prescribed Indian Minimum Seed Certification Standards (70%) while seeds obtained with hand pollination at three days interval had maximum germination (81.6%), minimum abnormal (3.1%) and most vigourous seedlings (1966.3). However, seeds obtained through open pollination were statistically (Pltoreq0.05) similar to hand pollination at three days interval for seed yield and quality traits. Merits and limitations of each pollination mode along with possible reasons for differential quality of so obtained hybrid seeds have been discussed.

To explore the role of dopamine and its metabolites for change of reproductive states of workers in honeybees (Apis mellifera), brain levels of dopamine relative substances were measured and localized in both normal workers and queenless workers. Dopamine and two possible metabolites of dopamine, N-acetyldopamine (NADA) and norepinephrine were detected in brain extracts. The brain levels of dopamine, NADA and norepinephrine were positively correlated with ovary development. Individuals with high dopamine levels had high levels of NADA or norepinephrine, suggesting that these metabolites might be involved in the change of reproductive sates of workers. Dopamine was distributed mainly in the protocerebrum, whereas NADA was in both the optic lobes and the protocerebrum. Dopamine levels in each distinct brain regions were higher in queenless workers than in normal workers, whereas there was a higher NADA level in the optic lobes in queenless workers than in normal workers. These results suggest that dopamine might be stored and/or released around the protocerebrum and the deutocerebrum, and also diffuse to the optic lobes where dopamine secretory cells are absent, resulting in high NADA levels in the optic lobes. The different manner of level changes of dopamine and its metabolites in each brain region might cause compound behavioural modulations in reproductive workers.

Nodulation is the first, and qualitatively predominant, cellular defense reaction to bacterial infections in insects. We tested the hypothesis that eicosanoids also mediate nodulation reactions to bacterial challenge in adults of a social insect, the honey bee, Apis mellifera. Treating newly -emerged experimental bees with the eicosanoid biosynthesis inhibitor, dexamethasone, impaired nodulation reactions to bacterial infections, and the influence of dexamethasone was reversed by treating infected insects with arachidonic acid, an eicosanoid precursor. Several other eicosanoid biosynthesis inhibitors, including the cyclooxygenase inhibitor, indomethacin, and the dual cyclooxygenase/lipoxygenase inhibitor, phenidone, also impaired the ability of experimental honeybees to form nodules in reaction to bacterial challenge. The influence of phenidone on nodulation was expressed in a dose-dependent manner. However, in experiments with older honey bees foragers, similar bacterial challenge did not evoke nodulation reactions. We infer from our results that while eicosanoids mediate cellular immune responses to bacterial infections in newly emerged honey bees, and more broadly, in most insect species, nodulation reactions to bacterial challenge probably do not occur in all phases of insect life cycles.

The endemic shrub Dillwynia juniperina is found in fragmented woodlands on the Northern Tablelands of New South Wales, Australia. The species obligatorily relies on pollinators to effect fruit-set and in this study the effect of fragmentation and the presence of the introduced honeybee on fruit-set was examined at two locations. Over two seasons Dillwynia juniperina was not pollen-limited indicating that flowers were saturated with pollen and that adequate bee servicing was occurring. Two native bee species (Leioproctus sp. 1 and Lasioglossum sp.) and the introduced honeybee, Apis mellifera L., were the most common visitors to flowers. Bee abundance varied between sites with honeybees being more common than native bees at one site. Native bees were never the most dominant pollinator. Visitation data show that native bees spend more time at flowers than introduced bees, although on average honeybees visit slightly more flowers on a bush than do native bees. Visitation data also revealed that native bee presence at bushes is negatively correlated with the presence of honeybees at the same bushes. At one of the study sites, honeybees were very abundant, but very few native bees were ever recorded over the 3 years. Results show that flowers can be pollinated from a single visit by a honeybee or native bee. Extrapolation of visitation data showed that native bees could on their own adequately service flowers in some years at some sites while at other times introduced honeybees may be necessary to augment pollination services.

A rising blood titer of juvenile hormone (JH) in adult worker honey bees is associated with the shift from working in the hive to foraging. We determined whether the JH increase occurs in anticipation of foraging or whether it is a result of actual foraging experience and/or diurnal changes in exposure to sunlight. We recorded all foraging flights of tagged bees observed at a feeder in a large outdoor flight cage. We measured JH from bees that had taken 1, 3-5, or RGT 100 foraging flights and foragers of indeterminate experience leaving or entering the hive. To study diurnal variation in JH, we sampled foragers every 6 h over one day. Titers of JH in foragers were high relative to nurses as in previous studies, suggesting that conditions in the flight cage had no effect on the relationship between foraging behavior and JH. Titers of JH in foragers showed no significant effects of foraging experience, but did show significant diurnal variation. Our results indicate that the high titer of JH in foragers anticipates the onset of foraging and is not affected by foraging experience, but is modulated diurnally.

alpha-Glucosidase III, which was different in substrate specificity from honeybee alpha-glucosidases I and II, was purified as an electrophoretically homogeneous protein from honeybees, by salting-out chromatography, DEAE-cellulose, DEAE-Sepharose CL-6B, Bio-Gel P-150, and CM-Toyopearl 650M column chromatographies. The enzyme preparation was confirmed to be a monomeric protein and a glycoprotein containing about 7.4% of carbohydrate. The molecular weight was estimated to approximately 68,000, and the optimum pH was 5.5. The substrate specificity of alpha -glucosidase III was kinetically investigated. The enzyme did not show unusual kinetics, such as the allosteric behaviors observed in alpha -glucosidases I and II, which are monomeric proteins. The enzyme was characterized by the ability to rapidly hydrolyze sucrose, phenyl alpha -glucoside, maltose, and maltotriose, and by extremely high Km for substrates, compared with those of alpha-glucosidases I and II. Especially, maltotriose was hydrolyzed over 3 times as rapidly as maltose. However, maltooligosaccharides of four or more in the degree of polymerization were slowly degraded. The relative rates of the ko values for maltose, sucrose, p-nitrophenyl alpha-glucoside and maltotriose were estimated to be 100,527, 281 and 364, and the Km values for these substrates, 11, 30, 13, and 10 mM, respectively. The subsite affinities (Ai's) in the active site were tentatively evaluated from the rate parameters for maltooligosaccharides. In this enzyme, it was peculiar that the Ai value at subsite 3 was larger than that of subsite 1.

Melittin (MLT), the 26-residue toxic peptide from the European honeybee Apis mellifera, is widely used for studying the principles of membrane permeabilization by antimicrobial and other host-defense peptides. A striking property of MLT is that its ability to permeabilize zwitterionic phospholipid vesicles is dramatically reduced upon the addition of anionic lipids. Because the mechanism of permeabilization may be fundamentally different for the two types of lipids, we examined MLT-induced release of entrapped fluorescent dextran markers of two different molecular masses (4 and 50 kDa) from anionic palmitoyloleoylphosphatidylglycerol (POPG) vesicles. Unlike release from palmitoyloleoylphosphatidylcholine (POPC) vesicles, which is highly selective for the 4 kDa marker, implying release through pores of about 25 ANG diameter (Ladokhin et al., Biophys. J. 72 (1997) 1762), release from POPG vesicles was found to be non-selective, i.e., 'detergent-like'. Oriented circular dichroism measurements of MLT in oriented POPG and POPC multilayers disclosed that alpha-helical MLT can be induced to adopt a transbilayer orientation in POPC multilayers, but not in POPG multilayers. The apparent inhibition of MLT permeabilization by anionic membranes may thus be due to suppression of translocation ability.

It is already known that the behaviour of the honeybee Apis mellifera is influenced by the Earth's magnetic field. Recently it has been proposed that iron-rich granules found inside the fat body cells of this honeybee had small magnetite crystals that were responsible for this behaviour. In the present work, we studied the iron containing granules from queens of two species of honeybees (A. mellifera and Scaptotrigona postica) by electron microscopy methods in order to clarify this point. The granules were found inside rough endoplasmic reticulum cisternae. Energy dispersive X-ray analysis of granules from A. mellifera showed the presence of iron, phosphorus and calcium. The same analysis performed on the granules of S. postica also indicated the presence of these elements along with the additional element magnesium. The granules of A. mellifera were composed of apoferritin-like particles in the periphery while in the core, clusters of organised particles resembling holoferritin were seen. The larger and more mineralised granules of S. postica presented structures resembling ferritin cores in the periphery, and smaller electron dense particles inside the bulk. Electron spectroscopic images of the granules from A. mellifera showed that iron, oxygen and phosphorus were co-localised in the ferritin-like deposits. These results indicate that the iron-rich granules of these honeybees are formed by accumulation of ferritin and its degraded forms together with elements present inside the rough endoplasmic reticulum, such as phosphorus, calcium and magnesium. It is suggested that the high level of phosphate in the milieu would prevent the crystallisation of iron oxides in these structures, making very unlikely their participation in magnetoreception mechanisms. They are most probably involved in iron homeostasis.

Even after considerable effort and debate, it remains unclear why honey bee queens frequently mate with 10 or more males. We address both why polyandry is adaptive to queens and how queens obtain such extreme numbers of mates. We review a manipulative experiment which tested the hypothesis that multiple mating reduces the genetic load caused by the honey bee sex determination system. Our results suggest that multiple mating (i.e., mating more than once) increases a queen's fitness by lowering the probability that she produces a high proportion of inviable, diploid males within her brood. Furthermore, we examined the relationship between a queen's mating behavior and her mating number. We propose that "extreme" polyandry in honey bees (i.e., mating numbers gtoreq 10) may be inadvertent consequences of a queen's mating behavior, therefore additional adaptive arguments are not needed to explain why honey bees have some of the highest mating numbers among the social insects.

Ultraviolet is an important component of the photic environment. It is used by a wide variety of animals and plants in mutualistic communication, especially in insect and flower inter-relationships. Ultraviolet reflections and sensitivity are also becoming well considered in the relationships between vertebrates and their environment. The relative importance of ultraviolet vis a vis other primary colours in trichromatic or tetrachromatic colour spaces is discussed, and it is concluded that ultraviolet is, in most cases, no more important that blue, green or red reflections. Some animals may use specific wavebands of light for specific reactions, such as ultraviolet in escape or in the detection of polarised light, and other wavebands in stimulating feeding, oviposition or mating. When colour vision and, thus, the input from more than a single spectral receptor type are concerned, we point out that even basic predictions of signal conspicuousness require knowledge of the neuronal wiring used to evaluate the signals from all receptor types, including the ultraviolet. Evolutionary analyses suggest that, at least in arthropods, ultraviolet sensitivity is phylogenetically ancient and undergoes comparatively little evolutionary fine-tuning. Increasing amounts of ultraviolet in the photic environment, as caused by the decline of ozone in the atmosphere, are not likely to affect colour vision. However, a case for which ultraviolet is possibly unique is in the colour constancy of bees. Theoretical models predict that bees will perform poorly at identifying pure ultraviolet signals under conditions of changing illumination, which may explain the near absence of pure ultraviolet-reflecting flowers in nature.

In order to examine the significance of hygienic behavior for the tolerance to varroosis of Africanized honey bees, they were compared with non -tolerant Carniolans in tropical Brazil. Capped worker brood cells were artificially infested with living Varroa mites, and inspected some days later. Uncapping, disappearance of the introduced mite and removal of the pupa were recorded in a total of manipulated 3,096 cells during three summer seasons. The hygienic response varied between Africanized and Carniolan colonies, but this difference was significant only in one year, during which Africanized honey bees removed a significantly greater proportion of Varroa mites than European honey bees. A high proportion of the mites disappeared from artificially infested brood cells without damage to the pupae. The opening of the cell and the removal of the bee brood are independent traits of a graded response by adult workers towards mite-infested brood cells. We found a higher between-colony variation in the reaction towards Varroa-infested brood of Africanized honey bees compared to Carniolans. The overall similar response of the two bee types indicates that hygienic behavior is not a key factor in the tolerance to varroosis of Africanized bees in Brazil.

Three oxalic acid (OA) solutions were applied to 24 honeybee colonies to test acaricidal effects on Varroa destructor. Daily natural mite drop per colony averaged 0.52. Higher mite mortality (18.33) was found after three August OA treatments. The mean efficacy's of the three water solutions of OA/sucrose (w/w), 3.4%/47.6%, 3.7%/26.1%, and 2.9%/31.9% applied in the presence of brood, was 52.28%, 40.66% and 39.16% respectively. A significantly higher efficacy was recorded when 3.4%/47.6% was applied in comparison to 2.9%/31.9% solution. There was no difference in efficacy between OA solutions administered during a broodless period on October 28. The average efficacy in all colonies was 99.44%. The results suggest that OA has limited acaricidal effect in colonies with brood, but it is highly effective in a broodless period.

A detailed technical description of a flight and rearing room for bees is provided, highlighting improvements made relative to other facilities. A primary innovation was the development of a draft-free air handling system capable of circulating large volumes of air with high rates of fresh air exchange and continuous electrostatic cleaning. This design has lead to a dramatic improvement in the quality of air recirculated in the flight room, and has prevented the recurrence of asthmatic symptoms in researchers to bee-produced aeroallergens. Other improvements include the incorporation of high-frequency fluorescent lamp ballasts and the choice of lamp types that provide a greater proportion of long-wavelength energy. Improvements in control system technology also have permitted more precise regulation of environmental conditions and the maintenance of a simulated diurnal cycle. Honey bees foraged in a manner similar to outdoor conditions and were free of behaviors associated with design problems seen in earlier flight rooms. Observations on bee behavior and colony performance are provided, and the utility of studying chemically based foraging attractants indoors is discussed.

Varroa destructor is a parasitic mite of the Asian honey bee, Apis cerana. Owing to host range expansion, it now plagues Apis mellifera, the world's principal crop pollinator and honey producer. Evidence from A. mellifera in far-eastern Russia, Primorsky (P) originating from honey bees imported in the mid 1800's, suggested that many colonies were resistant to V. destructor. A controlled field study of the development of populations of V. destructor shows that P colonies have a strong, genetically based resistance to the parasite. As control colonies (D) were dying with infestations of ca. 10 000 mites, P colonies were surviving with infestations of ca. 4000 mites. Several characteristics of the P bees contributed to suppressing the number of mites parasitizing their colonies.

The present work characterized the mitochondrial DNA (mtDNA) of five species of Plebeia (Plebeia droryana, P. emerina, P. remota, P. saiqui and P. sp.) and generate a data set to be used in further populational, phylogenetic, and biogeographic studies. The mtDNA of each species was analyzed using 17 restriction enzymes and restriction maps were built. A high level of interspecific variability was found. The total size of the mtDNA was estimated to be 18500 bp. Through a combination of PCR and examination of restriction fragment length polymorphism, the locations of 14 of the main mitochondrial genes were located on restriction maps. We verified a gene order identical to Apis mellifera.

In the central nervous system (CNS) of both vertebrates and invertebrates, biogenic amines are important neuroactive molecules. Physiologically, they can act as neurotransmitters, neuromodulators, or neurohormones. Biogenic amines control and regulate various vital functions including circadian rhythms, endocrine secretion, cardiovascular control, emotions, as well as learning and memory. In insects, amines like dopamine, tyramine, octopamine, serotonin, and histamine exert their effects by binding to specific membrane proteins that primarily belong to the superfamily of G protein-coupled receptors. Especially in Drosophila melanogaster and Apis mellifera considerable progress has been achieved during the last few years towards the understanding of the functional role of these receptors and their intracellular signaling systems. In this review, the present knowledge on the biochemical, molecular, and pharmacological properties of biogenic amine receptors from Drosophila and Apis will be summarized.

Conditioning the proboscis extension reflex of harnessed honeybees (Apis mellifera) is used to study the effect temporal spacing between successive conditioning trials has on memory. Retention is monitored at two long-term intervals corresponding to early (1 and 2 d after conditioning) and late long-term memory (3 and 4 d). The acquisition level is varied by using different conditioned stimuli (odors, mechanical stimulation, and temperature increase at the antenna), varying strengths of the unconditioned stimulus (sucrose), and various numbers of conditioning trials. How learning trials are spaced is the dominant factor both for acquisition and retention, and although longer intertrial intervals lead to better acquisition and higher retention, the level of acquisition per se does not determine the spacing effect on retention. Rather, spaced conditioning leads to higher memory consolidation both during acquisition and later, between the early and long-term memory phases. These consolidation processes can be selectively inhibited by blocking protein synthesis during acquisition.

As more transgenic crop plants become commercialised, there is an increasing need for information on their impacts on honey bees and bumblebees. Direct effects on bees may arise upon ingestion of proteins encoded by transgenes, if they are expressed in pollen, nectar or resin. Indirect effects may occur if plant transformation inadvertently changes flower phenotype. This review summarises current findings on effects of purified transgene product ingestion on adult bee gut physiology, food consumption, olfactory learning behaviour and longevity. Bt, protease inhibitor, chitinase, glucanase and biotin-binding protein genes are discussed. Results from tests conducted in the laboratory with individual adult bees and with colonies in the field are presented. Observations of bee foraging on transgenic plants kept under containment are also summarised. Results so far suggest that transgenic plant impacts on pollinators will depend on a case-by-case analysis of the gene concerned and its expression in the parts of the plant ingested by bees.

The authors tested the ability of 60 free-flying honeybees (Apis mellifera carnica) to discriminate a conditioning odor from an array of 26 simultaneously presented substances. The stimuli included 10 pairs of enantiomers and 6 essential oils. The bees (a) significantly distinguished between 98% of the 540 odor pairs tested, thus showing an excellent overall discrimination performance, and (b) were able to discriminate between the optical isomers of limonene, alpha-pinene, beta-citronellol, menthol, and carvone but failed to distinguish between the (+)- and (-)- forms of alpha-terpineol, camphor, rose oxide, fenchone, and 2-butanol. The findings support the assumptions that enantioselective molecular odor receptors may exist only for some volatile enantiomers and that insects and mammals may share common principles of odor quality perception, irrespective of their completely differing repertoires of olfactory receptors.

We examined the effects of sublethal doses (0.1, 1, and 10 ng per animal) of a new neonicotinoid insecticide, Imidacloprid, on habituation of the proboscis extension reflex (PER) in honeybees (Apis mellifera) reared under laboratory conditions. In untreated honeybees, the habituation of the proboscis extension reflex is age-dependent and there is a significant increase in the number of trials required for habituation in older bees (8 -10 days old) as compared to very young bees (4-7 days old). Imidacloprid alters the number of trials needed to habituate the honeybee response to multiple sucrose stimulation. In 7-day-old bees, treatment with Imidacloprid leads to an increase in the number of trials necessary to abolish the response, whereas in 8-day-old bees, it leads to a reduction in the number of trials for habituation (15 min and 1 h after treatment), and to an increase 4 h after treatment. The temporal effects of Imidacloprid in both 7- and 8-day-old bees suggest that 4 h after treatment the observed effects are due to a metabolite of Imidacloprid, rather than to Imidacloprid itself. Our results suggest the existence of two distinct subtypes of nicotinic receptors in the honeybee that have different affinities to Imidacloprid and are differentially expressed in 7 - and 8-day-old individuals.

Mouth-to-mouth food exchange in eusocial insects (trophallaxis) contributes to the organization of complex social activities. In the case of honeybees, foragers returning from a nectar source transfer the food collected to receiver colony-mates through oral contact. Previous studies have shown that the speed of nectar transfer within each contact (unloading rate) increases when foragers return from feeding sites with higher profitability, i.e. with more concentrated sugar solutions or higher solution flow rates. However, there is no evidence that the nectar unloading rate is actually evaluated by hive-mates during food exchange. To investigate this, trophallaxis between donor bees returning from a feeder with different flow rates of sucrose solution (range 1.0-8.2 mul min-1 of 50% w/w sucrose solution) and receiver hive-mates was studied by combining behavioural and infrared thermal analysis. The results show that when foraging bees returned from a feeder delivering a higher flow rate they initiated unloading at higher thoracic temperatures and transferred the solution at higher speed. During these food exchanges, the thoraces of receiver bees warmed up faster in proportion to increasing forager temperature and unloading rate. Therefore, whatever the variable actually evaluated by receivers (mostly nectar processors, i.e. bees that handle nectar in the hive) during trophallaxis (unloading rate and/or donor thoracic temperature), they raised their activity level in proportion to that of the foragers. In this way, receiver bees will intensify their nectar processing when nectar foragers return from more profitable sites.

A method based on solid-phase microextraction (SPME) followed by gas chromatography with nitrogen-phosphorus detection was developed for the purpose of determining 18 organophosphorus pesticide residues in honeybee samples (Apis mellifera). The extraction capacities of polyacrylate and poly(dimethylsiloxane) fibers were compared. The main factors affecting the SPME process, such as the absorption time profile, salt, and temperature, were optimized. The method involved honeybee sample homogenization, elution with an acetone:water solution (1:1) and dilution in water prior to fiber extraction. Moreover, the matrix effect on the extraction was evaluated. In samples spiked at the 0.2 mg kg-1 level, the coefficient variation was between 1 and 13% and the detection limits were below 10 mug kg-1. The SPME procedure was found to be quicker and more cost-effective than the solvent extraction method commonly used. The method was applied successfully to environmental screening. Parathion methyl was detected and confirmed in the real samples analyzed.

Previous investigations of haemolymph sugar levels in honeybees have reported very different results, probably because different experimental conditions affected the activity levels of the animals. The present study investigated the dependence of haemolymph sugar levels in foraging honeybees on metabolic rate and whether the haemolymph sugar level is regulated. Free-flying foraging bees were trained to collect controlled amounts of sucrose solution of different concentrations (15%, 30% or 50% sucrose w/w). Immediately after feeding, metabolic rate was measured over a given time depending on the sucrose concentration, then crop-emptying rate and haemolymph sugar levels were measured. Bees exhibiting a wide range of metabolic rates were compared to establish whether the observed differences in haemolymph sugar levels were due to limits in the supply of sugars from the crop or in the rate of trehalose synthesis in the fat bodies. Independent of the concentration of the sucrose solution supplied, haemolymph trehalose, glucose and fructose levels were constant for metabolic rates from 0 to 4.5 ml CO2 h-1. At higher metabolic rates, trehalose concentration decreased while that of glucose and fructose increased, with the exception of bees fed 15% sucrose solution. As the supply of sugar from the crop via the proventriculus was sufficient to support even the highest metabolic rates, the observed pattern must result from an upper limit in the capacity of the fat body to synthesise trehalose. The maximal rate of conversion of glucose to trehalose in the fat body was therefore calculated to average 92.4 mug glucose min-1. However, for bees fed 15% sucrose solution both the rate of conversion of glucose to trehalose and the rate of sugar transport from the crop to the ventricle were limited, together resulting in a decrease in total haemolymph sugar levels for metabolic rates higher than 5 ml CO2 h-1.

Efficacy of different honey bees (apis spp.) on seed setting was studied on five genotypes of berseem. Apis mellifera was found to be better pollinator than A. florea. Differential genotypic response of seed setting in diploid and tetraploid cultivars was seen which may be due to different flower size. Drastic reduction in seed set was observed when bees' visit was completely checked indicating thereby significant role of bees in pollination of berseem.

A highly nutritive culture medium (MGM-464) was developed for insect cell primary culture. The new medium consists of 6 inorganic salts, 4 organic acids, 21 amino acids, 3 sugars, 10 vitamins, and 8 other chemicals, including natural substances. The complete medium was generated by adding 20 ml fetal bovine serum to 100 ml MGM-464. The detail of the composition of the medium is given in a table, and the protocol to prepare the medium is described in the text. Among the 15 kinds of cultures made with MGM -464, embryonic cells from a walking stick and ovarian cells from the common white were subcultured more than 70 times, and embryonic cells of a chrysomelid beetle were subcultured more than 15 times. Other cultures could not be subcultured. However, embryonic cells from the commercial silkworm and a cockroach, ovarial cells from the commercial silkworm and a sphingid moth, nervous cells from the commercial silkworm and two sphingid moths, and cells from the dorsal vessel plus surrounding tissue of the commercial silkworm survived for several mo. The cells from the honeybee embryos, aphid embryos, and planthopper embryos were rather short-lived, and deteriorated after about 1 mo.

We analyzed sucrose responsiveness and associative tactile learning in two genetic strains of honey bees under laboratory conditions. These strains differ in their foraging behavior. Bees of the "high" strain preferentially collect pollen. "Low"-strain bees mainly forage for nectar. Responsiveness to different sucrose concentrations and tactile learning were examined using the proboscis extension reflex. Acquisition, extinction of conditioned responses, and responses to an alternative tactile stimulus were tested. High-strain bees are more responsive to sucrose than low-strain bees. Regardless of genotype, pollen foragers are more responsive to sucrose than nectar foragers. In bees of both strains we find the same relationship between responsiveness to sucrose and acquisition. Bees responding to low sucrose concentrations show more often the conditioned response during acquisition than those responding only to higher sucrose concentrations. Extinction of conditioned responses depends on the response probability during acquisition. Discrimination between the two tactile stimuli is affected by genotype but not by responsiveness to sucrose. High-strain bees discriminate better than low-strain bees. Our experiments thus establish links between division of labor, responsiveness to sucrose, and associative learning in honey bees.

The crab spider species Misumena vatia (Clerck 1757) can match its colour to the flowers it preys on. It can reversibly change between the colours white and yellow. For the first time, the spectral reflectance functions (including the ultraviolet) of such spiders are measured, and compared with the flowers on which they wait for prey. The bee-subjective similarity of the predators with their flowers is assessed using a model of colour vision for bees. While spiders are well matched to white flowers, the colour similarity between spiders and yellow flowers is not perfect. The UV-absorbing spiders often present themselves on UV -reflecting yellow flowers. From longer distances or for smaller flowers, however, bees may use only their green receptors, and spiders may therefore be well camouflaged. Also, spiders do not necessarily catch insects on the very flowers on which they sit; they sometimes move rapidly within respective infloresences.

Searching and Homing Times were studied in individually marked bees, which were repeatedly caught on leaving the feeder, displaced and released at an initially unknown site; under various celestial cues. On repetition, searching was reduced and homing times became shorter, differences being largest between first and second release. Homing times were longer in bees that had searched before. With overcast skies, these times were longer than with a blue sky, but only at first release. Searching, however, was not affected by celestial cues. Similarities are shown between searching and orientation flights. It is discussed that searching might not affect the vanishing bearing, but serve to fit the bee to the landmark reference system. The homing times of individuals uncover specific modes of home -finding efficiency.

The honey bee (Apis mellifera) behaviour and its pollination efficiency on sunflower hybrid seed production under different modes of pollination were studied. Caging with nylon mosquito net affected both the bee behaviour and its activity mainly due to differential micro environmental conditions, such as light and relative humidity. There was no effect of caging on air temperature. Per cent seed setting and number of seed per capitulum were at par under open and caged bee polliation conditions when compared with hand pollination. The seed weight was however, significantly low in caged bee and hand pollinated capitula compared to open pollinated capitula.

The aim of the present study is to characterize the way worker and queen ovaries differentiate in Apis mellifera, a species with trophic determination of female castes. A morphological study carried out with light and transmission electron microscopy showed that the differences in ovary development between the two castes begin as soon as the differential nursing of larvae is initiated. The decrease in ovariole number in worker ovaries is due to a process of cell death occurring in germinative cells and autophagic regression of somatic cells in the ovarioles that commence in the third instar larvae and proceed until the fifth instar where the process is more intense. Germinative cell death leads to ovariole disintegration and incorporation of the remaining somatic cells of the latter into the stromatic cells in such a way that the total volume of the ovary is little affected during larval development, although the ovariole number decreases. By the end of the larval stage, loss of cells is observed among the stromatic cells of the ovary. As a result, the ovary starts to decrease in volume and takes on the adult form.

A total of 738 colonies from 64 localities along the African continent have been analysed using the DraI RFLP of the COI-COII mitochondrial region. Mitochondrial DNA of African honeybees appears to be composed of three highly divergent lineages. The African lineage previously reported (named A) is present in almost all the localities except those from north-eastern Africa. In this area, two newly described lineages (called O and Y), putatively originating from the Near East, are observed in high proportion. This suggests an important differentiation of Ethiopian and Egyptian honeybees from those of other African areas. The A lineage is also present in high proportion in populations from the Iberian Peninsula and Sicily. Furthermore, eight populations from Morocco, Guinea, Malawi and South Africa have been assayed with six microsatellite loci and compared to a set of eight additional populations from Europe and the Middle East. The African populations display higher genetic variability than European populations at all microsatellite loci studied thus far. This suggests that African populations have larger effective sizes than European ones. According to their microsatellite allele frequencies, the eight African populations cluster together, but are divided in two subgroups. These are the populations from Morocco and those from the other African countries. The populations from southern Europe show very low levels of 'Africanization' at nuclear microsatellite loci. Because nuclear and mitochondrial DNA often display discordant patterns of differentiation in the honeybee, the use of both kinds of markers is preferable when assessing the phylogeography of Apis mellifera and to determine the taxonomic status of the subspecies.

This paper reviews prospective biological control agents of the varroa mite, Varroa destructor n. sp. (Acari, Mesostigmata). This ectoparasite has caused severe damage to populations of the European honeybee, Apis mellifera, world-wide in recent years. To date, no promising natural enemies of varroa species have been identified on A. mellifera or its original host, Apis cerana. Therefore, biological control will probably require natural enemies from other hosts. The following groups of organisms were reviewed as potential biological control agents: predatory mites, parasitoids and entomopathogens (nematodes, protozoa, viruses, Bacillus thuringiensis, rickettsiae, and fungi). The candidate groups were ranked according to their lethality to Acari, likely ability to operate under the physical conditions of honeybee colonies, ease of targeting, and ease of mass-production. Preferential consideration was given to the natural enemies of Acari that occupy taxonomic groups close to varroa. Entomopathogenic fungi, which kill a wide range of acarine species, were identified as prime candidates for screening against varroa. Bacillus thuringiensis also requires study, particularly strains producing novel toxins active against non-insect hosts. Entomopathogenic protozoa and nematodes show less potential for varroa control, but nonetheless warrant preliminary investigation. We consider predators, parasitoids, viruses and rickettsiae to have little potential to control varroa. Because the physical conditions within honeybee colonies are similar everywhere, it is very likely that a biological control agent of varroa could be used successfully throughout the world.

Neocypholaelaps indica Evans, a phoretic honey bee mite, infested colonies of both Apis mellifera Linn. and Apis cerana Fab. in the Shimla hills of Himachal Pradesh. As such, it caused no apparent damage to the colonies but in case of heavy infestation harmed the colonies by consuming honey and pollen stores and also lowered the food carrying capacity of the foragers by clinging to their various body parts. The adult mites and its different developmental stages were observed in the bottom board of the bee hive. The adults showed clear sexual dimorphism. The eggs were laid singly and the larval development occurred within the egg. The first nymphal stage was the protonymph, which got transformed into the second nymph, the deutonymph. The latter metamorphosed to adult mite. The phenomenon of sexual dimorphism was not exhibited by any of the nymphal stages.

To analyze morphologic and physiological properties of olfactory interneurons in the honeybee, Apis mellifera, antennal lobe (AL) neurons were intracellularly recorded and subsequently labeled with Neurobiotin. Additional focal injections were carried out with cobalt hexamine chloride and dextran fluorescent markers. Olfactory interneurons (projection neurons, PNs) project by means of five tracts, the lateral, the median, and three mediolateral antennocerebral tracts (l-, m-, and ml-ACT, respectively) to the mushroom bodies (MBs) and the protocerebral lobe (PL) of the ipsilateral protocerebrum. Uniglomerular PNs of the m- and l-ACT receiving input from a single glomerulus of the AL also arborize in different regions of the AL. The vast majority of l-ACT innervate the T1 region, whereas m-ACT neurons arborize exclusively in the T2, T3, and T4 regions (T1-4: AL projection area of sensory cells from the antennae). In the calyces of the MB, uniglomerular PNs form varicosities in the basal ring and the lip region. Individual neurons of both types exhibit unequal innervation within and between the two calyces. In addition, m-ACT fibers ramify more densely within the lip neuropil and show a higher incidence of spine-like processes than l-ACTs. In the PL, l-ACTs arborize exclusively within the lateral horn, whereas some m-ACT neurons innervate a broader region. Multiglomerular neurons of the ml-ACT leave the AL by means of three subtracts (ml-ACT 1-3). Two different types can be distinguished according to their protocerebral target areas: ml-ACTs projecting to the lateral PL (LPL) and to the neuropil around the alpha-lobe (tracts 2 and 3) and neurons projecting only to the LPL (tract 1). Intracellular recordings indicate that both l- and m-ACT neurons respond to general odors but with different response properties, indicating that odor information is processed in parallel pathways with different functional characteristics. Just like m-ACT neurons, ml-ACT neurons respond to odors with complex activity patterns. Bilateral interneurons, originating in the suboesophageal ganglion, connect glomeruli of both AL, and send an axon through the m-ACT in each hemisphere of the brain, terminating in the lip region of the calyces. These neurons respond to contact chemical stimuli.

The authors examined with questionnaires the importance of Varroa jacobsoni Oudemans infection in Hungarian apiaries, the control of this parasitosis and the judgement of its effectiveness by the bee-keepers themselves. The 141 answerers corresponded to 39.1% of those asked. On the basis of answers coming from all regions of the country the mite infection is present in all apiaries. Most of the answerers consider varroosis as the most important disease because it causes not rarely the rapid collapse and destruction of wintering colonies. Others consider the control very expensive without experiencing the necessary effectiveness. In each apiaries treatment is carried out at least once a year with different acaricide products. Most of them use Bayvarol and Antivar A. U. V. products and besides Perizin, Varroacid, Apivar, Api-life-var, Gabon PA 92 and Apistan was mentioned. 88.6% of the bee-keepers carry out the checks after the treatment but 23.4% of the answerers do not consider the control of mites effective. On the basis of these data the authors discuss the importance of mite infection and the difficulties in control with chemicals.

The objective of this study was to investigate the response of colonies of Apis mellifera iberica, relatively to worker brood cells artificially infested with the varroa mite, with the aim of applying the obtained results in the development of techniques directed to the detection and selection of bees tolerant to the mite. Cells with worker brood, 7 days after operculation were artificially infested with varroa mites. The hygienic behaviour of the bees, relatively to these cells was measured after a period of 24 h. The honeybees demonstrated two different behaviours. In the first, cleaned completely the cells, removing both brood and mites from the cells. In the second, bees uncapped and recapped the cells, removing the mites, but not the brood. The first of these behaviours was more constant than the second and assures a larger success relatively to the removal of the mites reproducing in the brood cells. The results were analysed with the propose of future techniques to localise and select bees tolerant to the mite.

The paucity of natural cavities within short-rotation hardwood agroforests restricts occupancy by cavity-nesting birds. However, providing 1.6 artificial nesting cavities (nest boxes)/ha within 3- to 10-year-old managed cottonwood forests in the Mississippi Alluvial Valley increased territory density of cavity-nesting birds. Differences in territory densities between forests with and without nest boxes increased as stands aged. Seven bird species initiated 38 nests in 173 boxes during 1997 and 39 nests in 172 boxes during 1998. Prothonotary warblers (Protonotaria citrea) and eastern bluebirds (Sialia sialis) accounted for 67% of nests; nearly all warbler nests were in 1.8-L, plastic-coated cardboard (paper) boxes, whereas bluebird nests were divided between paper boxes and 3.5-L wooden boxes. Larger-volume (16.5-L) wooden nest boxes were used by eastern screech owls (Otus asio) and great crested flycatchers (Myiarchus crinitus), but this box type often was usurped by honey bees (Apis mellifera). To enhance territory densities of cavity-nesting birds in cottonwood agroforests, we recommend placement of plastic-coated paper nest boxes, at a density of 0.5/ha, after trees are RGT 4 years old but at least 2 years before anticipated timber harvest.

The Dufour gland is found closely associated with the sting apparatus of all hymenopteran females, playing multiple roles among bees. In Apis mellifera Linnaeus, 1758 the gland is connected to the dorsal vaginal wall and, in queens, it produces egg-marking pheromones. In workers the function of this gland is unknown, except by its capacity to mimic the queen secretion in egg-laying workers. In an attempt to understand the development and to substantiate the present knowledge about the Dufour gland in A. mellifera, a morphometric study of the gland between and within the female castes was made. Glands of workers and queens with different ages and life stages were dissected and measured with an ocular micrometer adapted to a stereoscope. The results showed that the Dufour gland is larger in queens than in workers, and that among workers, the gland is larger in egg-laying and foragers than it is in newly emerged and nurse workers. The larger size of the gland in egg-laying queens and workers is in accordance with its role in reproduction. In forager workers the larger size of the gland suggest that, as happens in some species of bees, the gland may participate in pheromone production for nest-mate or nest-entrance recognition.

Chemical signals influence the selection of potential nest cavities by honey bee reproductive swarms. Attractants for swarms include the odors of old dark honey bee brood combs, odors from noncomb hive materials and propolis, and Nasonov pheromone, the odor released from the Nasonov glands of worker bees. Based on crossover and choice test experiments, swarms were shown to prefer, among otherwise identical cavities, those cavities containing Nasonov pheromone over cavities with only comb or other hive odors, cavities containing old comb over those with only noncomb odors or propolis, and cavities containing noncomb odors or propolis over those without bee or hive odor. Synergy between odors was not observed; that is, comb and/or noncomb hive odors did not enhance the attractiveness of Nasonov pheromone. The data support a model based on a hierarchy of olfactory attractants used by honey bee swarms, in order of highest to lowest: Nasonov pheromone, comb odor, noncomb and propolis odors, and, finally, absence of bee- or hive-produced odor.

Bumblebees (Bombus spp.) and honeybees, Apis mellifera, both use odour cues deposited on flowers by previous visitors to improve their foraging efficiency. Short-lived repellent scents are used to avoid probing flowers that have recently been depleted of nectar and/or pollen, and longer-term attractant scents to indicate particularly rewarding flowers. Previous research has indicated that bumblebees avoid flowers recently visited by themselves, conspecifics and congeners, while honeybees avoid flowers visited by themselves or conspecifics only. We found that both bumblebees and honeybees also avoided flowers previously visited by each other when foraging on Melilotus officinalis, that is, bumblebees avoided flowers recently visited by honeybees and vice versa. Twenty-four hours after a visit, this effect had worn off. Honeybees visited flowers that had been visited 24 h previously more often than flowers that had never been visited. The same was not true for bumblebees, suggesting that foraging honeybees were also using long-term attractant scent marks, whilst bumblebees were not. Flowers previously visited by conspecifics were repellent to bumblebees and honeybees for ca. 40 min. During this time, nectar replenished in flowers. Honeybees were previously thought to use a volatile chemical (2-heptanone) as a repellent forage-marking scent. We suggest that they may be using a less volatile chemical odour to detect whether flowers have recently been visited, possibly in addition to 2 -heptanone.

Hygienic behaviour, an intranidal task performed by middle-aged worker bees is an important behavioural mechanism of resistance to disease and to attack by Varroa destructor, an ectoparasitic mite. We studied the effect of a colony's genotypic composition on the expression of this behaviour among worker bees by creating normal age-structured colonies with different proportions of bees belonging to hygienic and nonhygienic lines. We established four colonies with 0, 25, 50 or 100% of worker bees belonging to the hygienic line. Analyses of the behaviour of hygienic bees in these colonies indicated that the performance of hygienic behaviour depended on the proportion of hygienic bees in the colony. Hygienic bees in the 25% hygienic colony performed the behaviour well beyond middle age and were more persistent at the task compared with bees from the same genetic line in the other colonies. However, the colony with all worker bees from the hygienic line was more efficient in achieving the task despite a lack of persistence. We also observed that in the colony with 50 and 100% hygienic bees, the behaviour was partitioned into subtasks, and some bees performed the subtask of uncapping cells at higher frequencies than the subtask of removing cell contents. These results suggest that a colony's genotypic composition influences the performance and partitioning of hygienic behaviour. We propose that the performance of hygienic behaviour and its partitioning into subtasks could be determined by response thresholds of individual worker bees and that the rate of behavioural ontogeny may be controlled by the demand for specific tasks.

Pollination entomofauna associated to raspberry cultivation was determined by direct observation and insect capture. Four pollinating agents were recorded; two of them, Apis mellifera L. and Corynura chloris Spin. were the most significant. Pollen grains carried on the insects body and pollen present in the digestive tract were counted. The bee carries a bigger pollen load, mainly in the thorax and did not show significant difference between morning and afternoon visits. C chloris is more active during the morning and carries similar quantities of pollen grains from several other species, including R. idaeus. Corynura chloris has pollen all over its body, and it lingers longer in the flowers than the bee. A. mellifera is a faithful and efficient pollinator of R. idaeus. Using the methods presented here, pollen load in pollinating insects can be determined qualitative and quantitatively.

We studied floral morphology and phenology of Macroptilium erythroloma, tested for self compatibility and examined the role of visitors. Flowers pass through three phases: a) wings brick colored (11 a.m. to 5 p.m.), when nectar and pollen are abundant, and stigmas are receptive; b) wings salmon pink (5 p.m. to 7 p.m.), when nectar is present, but pollinators may have already removed most pollen grains; and c) wings lilac (7 p.m. to 11 a. m. the following day) where the stigmas are not receptive, there are no rewards and the left wing is inclined 300 to the left. The visitors reject these flowers, which are retained for a period of 16 hours. Bombus morio, Apis mellifera and Pseudocentrort sp. trigger the pollinaton mechanism (brush type). The P/O ratio and the pollination treatments suggest that this species is facultatively xenogamous.

The genetic interactions between European and African-derived honey bees in the Neotropics are unclear. To study the abundance of males of each type, two apiaries with colonies of African-derived honey bee and European honey bee origin were established in the surroundings of one drone congregation area. The frequencies of African-derived honey bee and European honey bee males in the mating area were studied by taking samples of drones at the drone congregation area twice a month for 5 mo. Drones from each type of colony were identified by the use of two allozyme polymorphic systems: malate dehydrogenase (Mdh), hexokinase (Hk), and by haplotype using the EcoRI site of the mitochondrial DNA. The results of a Fisher exact test showed that, although Mdh alleles had similar frequencies across the time of study (P=0.095), the frequency of Hk alleles and haplotypes in drones varied between months (P=0.0001). Early in March, the frequencies of African-derived honey bee-typical alleles were significantly higher compared with European honey bee-typical alleles. However, at the end of the season of drone production in July, European honey bee-typical alleles were significantly more frequent in drones than those of the African -derived honey bee type. The results mirror the findings of an early peak of drone brood production reported for African-derived honey bee colonies compared with a peak later in the year in European honey bee ones. It is concluded that the seasonal frequencies of African-derived honey bee and European honey bee drones in the mating areas are not static. They vary in accordance with the different peaks of male production in their respective colonies. This behavior may act as a partial genetic barrier between bee types. The implications of these findings with respect to current levels of Africanization in this region of Mexico and for queen rearing in Africanized areas are discussed.

The genetic structure of Apis mellifera populations from the Canary Islands has been assessed by mitochondrial (restriction fragment length polymorphisms of the intergenic transfer RNAIeu-COII region) and nuclear (microsatellites) studies. These populations show a low level of genetic variation in terms of average number of alleles and degree of heterozygosity. Significant differences in the distribution of alleles were found in both data sets, confirming the genetic differentiation among some of the islands but not within them. Two mitochondrial haplotypes characteristic of the Canary Islands are found at high frequencies, although populations are introgressed by imported honeybees of eastern European C lineage. This introgression is rather high on Tenerife and El Hierro and low on Gran Canaria and La Gomera, whereas on La Palma it has not been recorded. The finding of microsatellite alleles characteristic of the eastern European lineage corroborates the genetic introgression. Phylogenetic analyses indicate that the Canarian honeybees are differentiated from other lineages and provide genetic evidence of their African origin.

Propolis is a complex product of the beehive. In Chile, propolis is only recently being submitted to systematic studies, particularly chemical analysis and scanning of pollen grains. We report the botanical origin of Chilean propolis from three Mediterranean type climate sites, Santa Cruz, Tanguao and Paine. We show that honey bees, Apis mellifera, visit the introduced species of Eucalyptus and Ricinus and five native Chilean species viz. Baccharis linearis, Buddleja globosa, Peumus boldus, Quillaja saponaria and Salix humboldtiana.

The hypothesis that parasites and pathogens select for polyandry in eusocial Hymenoptera was tested, using the honey bee Apis mellifera and its microsporidian parasite Nosema apis. Five honey bee colonies with low and five with high worker genetic diversity were infected with N. apis spores. At 54-56 days after inoculation, parasite spores in the workers' midguts were counted to determine whether there was a greater variation of infection intensity (spore counts per worker) in high-diversity colonies than in low-diversity ones. In all colonies there were two discrete sets of workers, with few or many parasite spores. To compare the variations of infection intensity between two colony groups, coefficients of variation were calculated for all workers examined, and for the slightly infected and strongly infected workers. The percentages of slightly infected workers in the low- and high-diversity groups were also compared. None of the comparisons between low- and high-diversity colonies showed significant differences, therefore no relation was found between honey bee workers' genetic diversity and their infection with N. apis.

Vinegar was obtained from bee (Apis mellifera) honey. The wort was prepared by diluting honey in distilled water to 21% total solids and by adding ammonium sulfate and ammonium phosphate. Saccharomyces cerevisiae was inoculated to the wort (4 g/L). Ethanol production was carried out at room temperature during 84 hours. In this study, 1 Kg of honey yielded about 5 L of wine, containing 8% alcohol (v/v), from a wort with 17.11% total sugars (w/v). The efficiency of the alcoholic fermentation was 81.34%. The acetic fermentation with an inoculum of mixed acetic microorganisms was performed by quick process in a 15 L vertical fermenter. This resulted in a vinegar containing up to 9% of acetic acid (w/v) and about 1% of alcohol (v/v). The acetic fermentation yielded between 91.24 and 97.21%. Approximately 5 L of honey vinegar with 9% acetic acid (w/v) were obtained from 1 Kg of bee honey. All attributes of honey vinegar showed acceptabililty index over 70%:95.37% for appearance, 94.81% for color, 79.07% for odor and 75.56% for flavor, indicating it would show good consumer acceptability.

Nine Campanula species occurring along the elevation gradient of Mt Olympos were studied regarding their pollination ecology. The main issues considered were 1) the relative importance of various insect taxa as Campanula pollinators, 2) the patterns of pollinators' size and activity as a function of altitude, 3) the effect of pollinator exclusion on floral longevity, and 4) the extent to which the morphological difference of C. versicolor from the other Campanula species on Mt Olympos is expressed in its pollinating fauna. The vast majority of Campanula pollinators were solitary bees. Andrenidae and Megachilidae bees (mainly Chelostoma campanulorum) dominated the pollinating fauna of most species. Melittidae and bumblebees were the commonest pollinators of high altitude species. Campanula versicolor differs from the other Campanula species in that its corolla is not bell-shaped but flat. Mainly Apis mellifera, syrphid flies, and carpenter bees, unlike all other Campanula species on Mt Olympos pollinated it. At the species level, rather large altitudinal differences of Campanula populations did not result into large diversification of their pollinating fauna. The insect visitation rate to flowers decreased with altitude. When pollinators were excluded, the floral longevity of the species examined increased three to five times. Neither flower phase (male of female) was consistently favoured in the absence of pollinators. The pollen loads of the different insect taxa (Apis mellifera included) were of variable purity. The majority of Megachilidae bees carried pollen loads of high purity. Pollen loads from insects visiting Campanula species at high altitudes did not differ significantly in their purity from those visiting lowland species. The distribution of Campanula pollinators' body size along the altitudinal gradient exhibited a U-shaped pattern. No relationship was found between insect-pollinator body size and corolla size of Campanula species.

To further understand the function of morphogenetic hormones in honeybee eye differentiation, the alterations in ommatidial patterning induced by pyriproxyfen, a juvenile hormone (JH) analogue, were studied by scanning and transmission electron microscopy. Prepupae of prospective honeybee workers were treated with pyriproxyfen and the effects on ommatidial differentiation were described at the end of the pupal development. The results show that the entire ommatidia, i.e., the dioptric as well as the receptor systems, were affected by the JH analogue. The wave of ommatidial differentiation, which progresses from the posterior to the anterior region of the pupal eyes, was arrested. In treated pupae, the rhabdomeres only differentiated at the apical axis of the retinula, the secondary and tertiary pigment cells did not develop their cytoplasm protrusions, and the cone cell quartet did not pattern correctly. Simultaneously, an intense vacuolization was observed in cells forming ommatidia. In a previous study we showed that pyriproxyfen exerts an inhibition on pupal ecdysteroid secretion. In this sense, the arrested ommatidial differentiation in pyriproxyfen-treated pupae could be due to a secondary effect resulting from an alteration in pupal ecdysteroid titers.

Electrophoretic analysis of non-specific esterases was performed in polyacrylamide gel of 1100 bees from 15 families and 3 populations inhabiting the Central Sredna Gora, West Rhodopes and Yambol region in different periods of ontogenesis. It was found that the synthesis of non -specific esterases in Apis mellifera L. is controlled by six independent gene loci, operating selectively during the separate stages of the ontogenesis. No interpopulation polymorphism of the studied esterase loci is observed. Sex-linked, sex-restricted or sex-dependent differences in the non-specific esterase loci were not investigated.

A worker honeybee performs tasks within the hive for approximately the first 3 weeks of adult life. After this time, it becomes a forager, flying repeatedly to collect food outside of the hive for the remainder of its 5 -6 week life. Previous studies have shown that foragers have an increased volume of neuropil associated with the mushroom bodies, a brain region involved in learning, memory, and sensory integration. We report here that growth of the mushroom body neuropil in adult bees occurs throughout adult life and continues after bees begin to forage. Studies using Golgi impregnation asked whether the growth of the collar region of the mushroom body neuropil was a result of growth of the dendritic processes of the mushroom body intrinsic neurons, the Kenyon cells. Branching and length of dendrites in the collar region of the calyces were strongly correlated with worker age, but when age-matched bees were directly compared, those with foraging experience had longer, more branched dendrites than bees that had foraged less or not at all. The density of Kenyon cell dendritic spines remained constant regardless of age or behavioral state. Older and more experienced foragers therefore have a greater total number of dendritic spines in the mushroom body neuropil. Our findings indicate that, under natural conditions, the cytoarchitectural complexity of neurons in the mushroom bodies of adult honeybees increases as a function of increasing age, but that foraging experience promotes additional dendritic branching and growth.

The perception of sugar is important to honey bees for making foraging decisions. We measured bees' perception by determining what concentration of sucrose touched to the antennae elicited the proboscis extension response (response threshold). A low response threshold (extension at low concentration) suggests a high perceptual value of sucrose, and vice versa. Perception of sucrose solutions differed between two artificially selected genotypic strains and was modulated by the bees' recent feeding experiences. Bees offered 10%, 30%, or 50% sucrose solutions in small cages overnight, and in large flight-cages or free-flying in the field for several days, had subsequent response thresholds positively correlated to the concentration offered. Empty bees, whether they were nectar, water or pollen foragers, dancers or non-dancers, had a significantly lower threshold than loaded bees. Crop volume affected response thresholds directly and independently of sucrose concentration. We interpret these findings as multiple mechanisms that operate in different time scales, modulating perception of sucrose. Changes occurred in the time scale of evolutionary processes as demonstrated by genotypic differences. Changes with foraging experience occur in hours or minutes while effects of crop filling are instantaneous.

The influence of honey bee (Apis mellifera L.) pollination of kiwifruit (Actinidia deliciosa (A.Chev.) C.F. Liang et A.R. Ferguson) under different pollination regimes (viz. honey bee supplementation, honey bee saturation in a cage with a single male cultivar, and honey bee exclusion) was investigated under Australian conditions during 1993/94 and 1995/96 seasons. Vines that had no access to honey bees had significantly (Pltoreq0.01) lower fruit set (24%) compared to honey bee supplementation (91%) and bee saturation (89%). The mean yield (kg/vine) and the mean number of fruit/vine in bee-supplemented and bee-saturated treatments did not differ significantly, although vines that were excluded from honey bees produced significantly (Pltoreq0.01) lower yields. However, individual fruit weight in the bee-saturated treatments was affected. There were significantly more small fruit in bee-saturated vines than in vines that were supplementary pollinated by honey bees. Bee activity as assessed by the number of bee visits on flowers (bees/vine per min) was significantly higher on male vines than female vines during the first 2 weeks of the flowering period. Honey bees were the main contributor to pollination and fruit set, although low numbers of other potential insect pollinators such as ladybird beetles and hover flies were also observed. The mean seed numbers in comparable fruit from higher weight groupings (i.e., 70-89, 90-109, and gtoreq110 g) in bee-supplemented and bee -saturated vines did not differ significantly, suggesting adequate pollination and fertilisation of ovules in these two treatments. Vines that were caged with a single male cultivar produced fruit with significantly higher (Pltoreq0.01) total soluble solids concentration than did those that were honey bee supplemented. Possible reasons for the reduced mean fruit weight under honey bee saturation are discussed.

Quantitative chemical analyses of cuticular waxes of the honeybee Apis mellifera with gas chromatography and mass spectrometry showed significant differences in the chemical composition of cuticular waxes from drones and workers performing different tasks. We used the proboscis extension reflex to test the ability of bees to discriminate between these cuticular waxes. Differentially conditioned bees significantly discriminated between cuticular waxes of drones, food storers, foragers and queen attenders. We found that the esters and polar components in the cuticular waxes provide the discriminative cues for the insects.

Little is known about the development of the overwintering population of honey bees (Apis mellifera) colonies in temperate climates. Colonies were subjected to one of four requeening treatments: requeened in mid-summer with a mated, virgin or colony-reared queen, or left with the original queen (control). Worker survival in cohorts of newly emerged bees introduced to colonies in late summer and fall was followed until all marked bees had died. Winter bees were reared over a relatively similar length of time in all treatments, but they appeared earlier in control colonies compared to requeened colonies. The gradual increase in proportion of winter bees over time was similar among treatments, but requeened colonies lagged behind control colonies. The bulk of winter bees appeared much earlier in control colonies than in colonies that were requeened. This response demonstrates that cues within the colony (i.e., differences due to requeening) are perceived by workers as part of the conditions that influence summer bee or winter bee status.

Acute oral and contact toxicity tests of imidacloprid, an insecticide acting agonistically on nicotinic acetylcholine receptors (nAChR), to adult honeybees, Apis mellifera L var carnica, were carried out by seven different European research facilities. Results indicated that the 48-h oral LD50 of imidacloprid is between 41 and RGT 81 ng per bee, and the contact LD50 between 49 and 102 ng per bee. The ingested amount of imidacloprid-containing sucrose solution decreased with increasing imidacloprid concentrations and may be attributed to dose-related sub -lethal intoxication symptoms or to antifeedant responses. Some previously reported imidacloprid metabolites occuring at low levels in planta after seed dressing, ie olefine-, 5-OH- and 4,5-OH-imidacloprid, showed lower oral LD50 values ( RGT 36, RGT 49 and 159 ng per bee, respectively) compared with the concurrently tested parent molecule (41 ng per bee). The urea metabolite and 6-chloronicotinic acid (6-CNA) exhibited LD50 values of RGT 99 500 and RGT 121 500 ng per bee, respectively. The pharmacological profile of the (3H)imidacloprid binding site in honeybee head membrane preparations is consistent with that anticipated for a nAChR. IC50 values for the displacement of (3H)imidacloprid by several metabolites such as olefine, 5 -OH-, 4,5-OH-imidacloprid, urea and 6-CNA were 0.45, 24, 6600, RGT 100 000, and RGT 100 000 nM, respectively. Displacement of (3H)imidacloprid by imidacloprid revealed an IC50 value of 2.9 nM, thus correlating well with the observed acute oral toxicity of the compounds in honeybees. Neurons isolated from the antennal lobe of A mellifera and subjected to whole-cell voltage clamp electrophysiology responded to the application of 100 muM acetylcholine with a fast inward current of between 30 and 1600 pA at -70 mV clamp potential. Imidacloprid and two of the metabolites (olefine- and 5-OH-imidacloprid) acted agonistically on these neurons, whereas the others did not induce currents at test conencentrations up to 3 mM. The electrophysiological data revealed Hill coefficients of approximately 1, indicating a single binding site responsible for an activation of the receptor and no direct cooperativity or allosteric interaction with a second binding site.

Africanized honey bees (Apis mellifera L. near scutellata Lepeltier) arrived in southern Arizona in 1993. Since their first appearance, much attention has been focused on these "killer bees." Although the initial excitement has decreased, questions about their impact remain. Attacks on domestic animals have captured the attention of the local media, causing increasing concern among pet owners and veterinarians. Are attacks becoming more common with the increase in the Africanized honey bee population, or are the attacks simply drawing excessive attention due to their dramatic nature? To answer these and related questions, veterinary clinics/hospitals in and around Tucson were surveyed. A questionnaire was designed to elicit information about the number and type of animal attacks that veterinarians see most frequently. The data derived from more than 5,000 animal attacks provide the first record of the true extent and severity of bee attacks relative to attacks by other animals. Cats and dogs accounted for the greatest number of attacks on pets. Dog attacks led to the most severe injuries, resulting in the majority of reported deaths. Snakes followed a distant third place in frequency of injury on pets. Honey bee attacks placed sixth in attack frequency and produced no permanent injuries and few deaths among the pet population. Perhaps the most remarkable finding is the relationship vis-a-vis perception and reality held by the public; that is, bee attack frequency and severity is much less than perceived.

A study was conducted to determine the efficacy of ground ultra-low-volume malathion sprays on honey bee (Apis mellifera L.) apiaries in open and forested areas downwind from the spray route. Impact on colonies 7.6, 15.2, 47.7, and 91.4 m downwind from sprays was assessed by recording individual bee mortality 12 and 36 h after treatment. In addition, hives were weighed before as well as during the study and cluster counts were conducted at each hive to determine colony strength before and after treatment. Spray drift was monitored by the use of caged mosquito (Culex quinquefasciatus Say) mortality and deposition on filter paper. During the study, significant bee mortality in the open area occurred on 2 occasions at 7.6 m (16.8 +- 4.3 bees, 11.8 +- 7.0 bees) and at 15.2 m (6.5 +- 1.7 bees, 5.3 +- 1.5 bees). Significant mortality in the forested area was observed only once and consisted of 2 bees at 7.6 m. In each case where bee mortality occurred, spray deposits on filter papers had exceeded 400 ng/cm2. Although mortality of caged mosquitoes indicated that malathion drifted through the study areas, little correlation was apparent between mortality and spray deposition on filter paper.

Studies on the different ways of reproduction of Stenolobium stans (Juss.) Seem and on the diversity, frequency and constancy of flower-visiting insects at different hours were carried out during four years. The S. stans flowers open between 5 and 6 am during 3 to 8h, with 90% pollen viability. Besides the pollen, the flower has other features that are attractive to the visiting insects, like osmophores responsible for a sweet odor, ultra-violet reflected light and nectar at 25% of sugar. The plant is autocompatible and reproduces by autogamy, geitonogamy or xenogamy. This behavior demands external pollination and justifies the species to be a serious invasor of grounds and pastures. Large diversity of insects were observed visiting the flowers, with predominance of bees. The pollinators species were Centris collaris Lepeletier, Bombus morio (Swederus), Eulaema nigrita Lepeletier and Epicharis sp. The incidence of native species was lower at the rural area than at the urban one, with predominance of the exotic Apis mellifera L. The environmental factors, mainly temperature, light, relative humidity and wind speed, influenced the foraging activity of the insects.

The response of worker bees of Apis mellifera ligustica, A. mellifera carnica and A. mellifera syriaca to Varroa jacobsoni was investigated using a total of seven colonies for each honey bee race at the Jordan University of Science and Technology campus in Irbid, Jordan. The defense behavior of bees was measured by the degree of damaged mites that dropped from naturally infested colonies on to inserts placed under the brood nest. Results revealed that worker bees in A. mellifera syriaca colonies amputated on average 25.7% of all dropping mites, while the average percentage of injured mites in the colonies of A. m. ligustica and A. m. carnica were 11.2% and 13.5%, respectively. A significant difference in the grooming activity was detected in A. mellifera syriaca colonies as compared to that in other honey bee subspecies. Pigmented mites were significantly more damaged than less pigmented mites among all races. Amputation to the first three pairs of legs was most observable. Grooming by worker bees of three races provide evidence for active mechanisms of resistance against the parasitic mite, Varroa jacobsoni.

Foraging behaviour of Apis spp. on the flowers of Brassica campestris var. sarson, Allium cepa L., Daucus carota L., Tripolium alexandrinum L. and Helianthus annuus L. was observed at Chaudhary Charan Singh Haryana Agricultural University, Hisar during November (mustard), April (onion and carrot) and May (berseem and sunflower), respectively. Apis florea spent maximum time per flower (3.54, 7.43, 37.09 and 15.24 sec.) and visited least number of flowers/umbels (6.7, 2.6, 2.2 and 3.6) per minute on mustard, onion, carrot and Egyptian clover, respectively. However, A. mellifera spent least time (1.64, 8.58 and 128.47 sec.) per flower/head and tripped highest number of flowers/head (15.2, 8.2 and 1.2) per minute or 5 min on mustard, Egyptian clover and sunflower followed by A. dorsata who spent 2.18, 2.48, 11.46 and 186.73 sec. per flower and visited 12.0, 3.7 and 1.5 flowers/head per minute except sunflower where the observation time was 5 min. All the bees foraged as top workers on all the crops except A. florea which foraged as side worker on Brassica flowers.

Newly emerged adult bees were fed with Nosema apis spores subjected to various treatments, and their longevity, proportions of bees infected, and spores per bee recorded. Spores lost viability after 1, 3, or 6 months in active manuka or multifloral honey, after 3 days in multifloral honey, and after 21 days in water or sugar syrup at 33degreeC. Air-dried spores lost viability after 3 or 5 days at 40degree, 45degree, or 49degreeC. Increasing numbers of bees became infected with increasing doses of spores, regardless of their subsequent food (active manuka honey, thyme honey, or sugar syrup). Final spore loads were similar among bees receiving the same food, regardless of dose. Bees fed with either honey had lighter infections than those fed with syrup, but this may have been due to reductions in their longevity. Bees fed with manuka honey were significantly shorter lived, whether infected or not.

Proboscis extension reflex conditioning has often been used to study olfactory learning in the honey bee. However, only a few studies have explored the variability of this response relative to the age of the bees, and these studies have yielded different conclusions. We aimed to document the effect of age on the proboscis extension response by measuring three parameters in the experimental procedure: the level of spontaneous responses, the acquisition rate, and the resistance to extinction. The performance of the youngest bees (2-day and 4-day-old) differed from those of older individuals for the three parameters, which may be related to the ontogeny of the olfactory system. In older age-groups, only the resistance to extinction was found to vary with age. We discuss the possible relationships between age-dependent variations in the odour learning abilities and the division of labour in the colony.

The quantity and composition of the six major mandibular gland components of young queenless workers of the Cape honeybee (Apis mellifera capensis) were determined. The total amount of the six components increased with age. The relative quantities in the mandibular gland secretion of queenless caged workers were found to change rapidly during the first 4 days after emergence and to become dominated by the queen substance, 9 -keto-2(E)-decenoic acid. Also the relative amounts of 9-hydroxy-decenoic acid, a precursor of the queen substance, showed an increase of an order of magnitude within the first 4 days of imaginal life. The relative amounts of the aromatic compounds typical to the queen pheromone remained similar in this developmental time window. The increase of queenlike compounds is particularly strong between days two and three after emergence. These queen-like pheromones play a major role in the development of reproductive hierarchies among workers under queenless conditions. This may be an important factor in the socio-parasitic pathway of A. m. capensis.

In the field of insect circadian rhythms, the honey bee is best known for its foraging time-sense, or Zeitgedachtnis, which permits the forager bee to make precise associations between the presence of food and the time of day. A number of studies, now considered classics, established that bees could be trained to collect food at virtually any time of the circadian cycle and that this timekeeping ability was controlled by an endogenous circadian clock. Recently, behavioral rhythms in bees have been examined using a variety of approaches, in both laboratory and field studies. The following areas of new research are reviewed: (a) the ontogeny of behavioral rhythmicity in newly emerged worker bees; (b) the integration of behavioral rhythmicity with the colony's division of labor; (c) the evidence for social entrainment of behavioral rhythms and for a 'clock of the colony'; (d) the potential linkage between circadian rhythms of general locomotor activity and the foraging time-sense; (e) learning and entrainment hypotheses proposed to explain the mechanism underlying the time-sense; (f) the interplay between extinction and persistence of the time-memory as revealed from the differential behavior of individuals within the foraging group; and (g) comparisons of the Zeitgedachtnis with food-anticipatory rhythms in other animals.

The endocannabinoid system exerts an important neuromodulatory role in mammals. Knockout mice lacking cannabinoid (CB) receptors exhibit significant morbidity. The endocannabinoid system also appears to be phylogenetically ancient-it occurs in mammals, birds, amphibians, fish, sea urchins, leeches, mussels, and even the most primitive animal with a nerve network, the Hydra. The presence of CB receptors, however, has not been examined in terrestrial invertebrates (or any member of the Ecdysozoa). Surprisingly, we found no specific binding of the synthetic CB ligands (3H)CP55,940 and (3H)SR141716A in a panel of insects: Apis mellifera, Drosophila melanogaster, Gerris marginatus, Spodoptera frugiperda, and Zophobas atratus. A lack of functional CB receptors was confirmed by the inability of tetrahydrocannabinol (THC) and HU210 to activate G-proteins in insect tissues, utilizing a guanosine-5'-O-(3 -(35)thio)-triphosphate (GTPgammaS) assay. No orthologs of human CB receptors were located in the Drosophila genome, nor did we find orthologs of fatty acid amide hydrolase. This loss of CB receptors appears to be unique in the field of comparative neurobiology. No other known mammalian neuroreceptor is understood to be missing in insects. We hypothesized that CB receptors were lost in insects because of a dearth of ligands; endogenous CB ligands are metabolites of arachidonic acid, and insects produce little or no arachidonic acid or endocannabinoid ligands, such as anandamide.

Chemical analyses revealed that the labial gland complex of worker honeybees possesses a series of hydrocarbons dominated by odd-numbered carbon chain alkanes along with minor amounts of alkenes and branched alkanes. Foragers contained significantly more secretion than nurse bees. Experiments with bees from colonies induced to have a division of labor independent of age revealed that the differences in the amount of secretion were task, but not age dependent.

A peptide fraction was isolated from honeybee royal jelly (RJ) using dual dialysis under acidic conditions. The N-terminal amino acid sequence of the major peptide within the fraction was V-T-C-D-L-L-S-F-K-G. This sequence corresponds to the honeybee defensin royalisin of MW 5523 Da which has been shown to exert antibacterial activity against some Gram -positive bacteria. Diffusion tests on agar plates showed that the peptide fraction had an inhibitory effect against the honeybee pathogen Paenibacillus larvae larvae, the primary pathogen of American foulbrood disease, as well as against other Gram-positive bacteria such as Bacillus subtilis and Sarcina lutea. Moreover, the peptide fraction was shown also to have antifungal effect against the model fungus Botrytis cinerea. It is the first evidence of an antibiotic effect of royalisin against a honeybee pathogen. The procedure described is very simple and does not require application of complicated separation techniques. It is based on dialysis of RJ using membranes with different pore sizes, which enable to separate the compounds having molecular weight below 2 kDa, between 2 kDa and 10 kDa, and over 10 kDa.

The spatial distribution of worker honeybees in colonies of two African subspecies (Apis mellifera capensis and Apis mellifera scutellata), as well as their natural hybrids, was determined in five observation colonies, each containing one frame. The queens were allowed to roam freely throughout the hive during the initial phase of the experiment, and were observed on both sides of the frame in all colonies. In the second phase of the experiment the queen was caged on one side of the frame in three of the observation colonies, the other two colonies serving as controls. Queen caging significantly affected the distribution of worker bees, with more A. m. scutellata workers being attracted to the queen and more A. m. capensis worker bees being repelled by the presence of the queen. The hybrid workers were also repelled, but to a lesser extent. Queens thus not only attract workers to form a retinue or during swarming but also repel workers in the nest. Evasion of the reproductive suppression by the queen pheromones may be a typical behavior for workers with a high reproductive potential.

Hygienic behaviour of mite-tolerant Africanized and susceptible Carniolan colonies was evaluated in Brazil by sham-manipulating or artificially inoculating 4175 capped worker brood cells with dead Varroa destructor mites or ants, or their odour extracts. Both bee types expressed the hygienic components 'uncapping', 'removal of introduced mite/ant' and 'removal of brood' to the same extent and pattern. The similar response to dead mites of different origins and solvent-extracted mites indicates a minor role of scent or of movement of mites within sealed brood cells as releasers of hygienic behaviour. However, application of dichlormethane -extract of mites increased the hygienic response compared to pure solvent alone. Hygienic reactions to mite infested brood cells must, therefore, be elicited by other signals, possibly by the detection of specific reactions or odours of the infested larvae or pupae.

The change in infestation levels of the mite Varroa destructor Anderson and Trueman on adult bees during periods with little or no brood rearing (late October/early November to early February) was investigated in 10 colonies for two consecutive years in a Swedish climate (N57degree06'E18degree16'). The results do not support the hypothesis that mites become concentrated on the remaining bees as bees die off from the winter cluster. When the number of all mites recovered from dead bees or from debris was used to calculate mites per dead bee, the level of infestation per bee was not significantly different between samples of live bee and dead bees. For modelling purposes, we presently find no reason to differentiate the mortality rates of bees and mites during periods when there is no or limited amounts of brood in the colonies, although the connection between bee mortality and mite mortality may not be as direct as previously assumed.

Temporary polygyny (the presence of multiple queens) occurs in honeybee colonies when virgin queens (VQs) are reared for reproductive swarming or queen replacement. During these events, workers perform vibration signals on queen cells and emerged queens, and these signals may influence which VQ becomes the new laying queen of a colony. We examined the role of vibration signals during queen competition in two African and six European honeybee colonies. There was pronounced variability in vibration activity between colonies and among queens reared within the same colony. Despite this variation, all colonies showed similar trends in the relationships between the vibration signal and queen replacement. Vibration signals performed on queen cells were not associated with emergence success. Likewise, the signal was not associated with queen emergence order. Early emerging and late-emerging queens were vibrated at similar rates, and there was no clear relationship between emergence order and VQ survival. However, the signals performed on VQs after they emerged were associated with their behaviour and success during the queen elimination period. Emerged VQs that were vibrated at higher rates survived longer, performed more bouts of piping (a characteristic sound produced by queens), eliminated more rivals and were more likely to become the new queens of the colonies. The vibration signal may therefore allow workers a degree of control over the behaviour of emerged VQs, and may influence the outcome of queen competition in honeybees. Differences in vibration activity within and among colonies may reflect differences in the extent to which workers and queens conflict over the timing and outcome of polygyny reduction.

Honeybees can use various kinds of information, including color and pattern, in choosing flowers during foraging. We offered free-flying bees a dimorphic artificial patch of radial and bilateral blue/white flowers in order to examine three hypotheses to explain the noted increase in visitation to the flower type offering a lower caloric reward, i.e., optical resolution, dyslectic interpretation, and cognition related to pattern colors. When bees were offered a color pattern rather than a simple color difference to differentiate flower types, they did not always make choices predicted by theory. Honeybees foraged randomly on both flower morphs when rewards were equal and chose the higher caloric reward more often when rewards were different. However, they visited the less rewarding choice more than 33% of the time. Increasing the size of the flower surface by doubling the dimensions did not decrease visitation to the less rewarding flower type, suggesting that visual acuity is not the limiting factor in flower sizes used. When flower colors that increased contrast (yellow vs. blue) were used in the dimorphic patch, visitation rate to the less rewarding flower type did not decline, nor did this 'error rate' decrease when identical patterns were used with only partial color differences. Adding an orientation reference on each flower decreased the frequency with which the less rewarding flower type was chosen from 36 to 26%, possibly because foragers were induced to switch from a global cue (e.g., patch) to a local cue (e.g., flower). The rate with which the less rewarding flower type is chosen appears to be a function of honeybee use of cognitive and sensory modalities, rather than limited memory and correlative abilities.

Worker bees eventually begin laying eggs in honey bee colonies that have lost their queen and have failed to rear a replacement. In contrast, workers tend to lack developed ovaries and tend to suppress drone production by worker nestmates in colonies with queens. We measured changes in worker egg-removal behaviour, ovary development, and egg-laying rate in hives following the removal of their queens. We carried out weekly assays of worker removal of experimentally transferred eggs, dissection and inspection of worker bee ovaries, and daily checks of worker oviposition. Following queen removal, the egg-removal rate by workers generally first increased, then decreased or levelled off over the four -week time course of the experiment; this behaviour was closely synchronized with the increase in worker ovary development and egg-laying. We discuss our results in the context of theoretically predicted worker -worker conflict over the onset of reproduction in queenless honey bee societies.

D-002 is a mixture of high-molecular-weight aliphatic alcohols, obtained from bees wax (Apis mellifera), with mild anti-inflammatory properties and effective anti-ulcer activities demonstrated in experimental models. This study investigated the oral toxicity of D-002 administered for 1 year to beagle dogs. Twenty-four beagle dogs (12 males and 12 females) were distributed randomly in three experimental groups (four animals per group): a control and two treated groups received D-002 at 50 and 250 mg kg-1 (7 days/week) by gastric gavage. Overall, D-002 was well tolerated throughout the study. No signs or symptoms of toxicity were observed, and no mortality occurred during the study. All groups showed similar weight gain and food consumption. No hematological, blood biochemical or histopathological disturbances attributable to treatment were observed. This study shows no drug-related toxicity induced by long-term administration of up to 250 mg kg-1 D-002 to beagle dogs.

We asked whether the detection range of two-coloured centre-surround patterns differs from that of single-coloured targets. Honeybees Apis mellifera were trained to distinguish between the presence and absence of a single-coloured disc or a coloured pattern at different visual angles. The patterns presented colours which were either different in chromatic and L-receptor contrasts to the background, equal in chromatic but different in L-receptor contrasts, or vice-versa. Patterns with colours presenting only chromatic contrast were also tested. Patterns with higher L-receptor contrast in its outer than in its inner element were better detected than patterns with a reversed L-contrast distribution. However, both were detected worse than single-coloured discs of the respective colours. When the L-receptor contrast was the same for both elements, the detection range of the two-coloured and single-coloured targets was the same. Patterns whose colours lacked L-receptor contrast were detected just as single-coloured targets of the same colours. These results demonstrate that both chromatic and L-receptor contrasts mediate the detection of coloured patterns and that particular distributions of L-receptor contrast within a target are better detected than others. This finding is consistent with the intervention of neurons with centre-surround receptive fields in the detection of coloured patterns.

Many physiological systems appear to have safety margins, with excess capacity relative to normal functional needs, but the significance of such excess capacity remains controversial. In this study, we investigate the effects of parasitic tracheal mites (Acarapis woodi) on the safety margin for oxygen delivery and flight performance of honeybees. Tracheal mites did not affect the flight metabolic rate of honeybees in normoxic (21% oxygen) or hyperoxic (40% oxygen) air, but did reduce their metabolic rate relative to uninfected bees when flying in hypoxic air (5 or 10% oxygen), demonstrating that mites reduced the safety margin for tracheal oxygen delivery. The negative effects of mites on flight metabolic rate in hypoxic atmospheres were graded with the number of mites per trachea. For example, in 10% oxygen atmospheres, flight metabolic rate was reduced by 20% by moderate mite infection and by 40% by severe mite infection. Thus, the safety margin for oxygen delivery in honeybees allows them to retain normal flight metabolic rate and behavior despite tracheal mite infection under most conditions. However, the reduction in tracheal gas-exchange capacity may constrain activities requiring the highest metabolic rates, such as flying in cool weather. In support of this hypothesis, bees that were unable to return to the hive during late-winter flights showed significantly higher levels of mite infection than bees that returned safely.

Honeybees (Apis mellifera L.) sampled at sites in Europe, Africa and South America were analysed using a mitochondrial DNA restriction fragment length polymorphism (RFLP) marker. These samples were used to provide baseline information for a detailed analysis of the process of Africanization of bees from the neotropical Yucatan peninsula of Mexico. Radical changes in mitochondrial haplotype (mitotype) frequencies were found to have occurred in the 13-year period studied. Prior to the arrival of Africanized bees (1986) the original inhabitants of the Yucatan peninsula appear to have been essentially of southeastern European origin with a smaller proportion having northwestern European ancestry. Three years after the migration of Africanized bees into the area (1989), only very low levels of maternal gene flow from Africanized populations into the resident European populations had occurred. By 1998, however, there was a sizeable increase in the proportion of African mitotypes in domestic populations (61%) with feral populations having 87% of mitotypes classified as African derived. The results suggest that the early stages of Africanization did not involve a rapid replacement of European with African mitotypes and that earlier studies probably overestimated the prevalence of African mitotypes.

Drones reared in colonies of honey bees (Apis mellifera) of European (EHB) and Africanized (AHB) origin were characterized using morphometrics and allozyme analyses. 17 characters of the forewing were compared at the univariate and multivariate level using principal component analysis (PCA). Additionally, Mdh and Hk allozyme frequencies were compared between both drone types. Only 5 forewing characters were statistically different between the two drone types and PCA failed to separate clearly AHB from EHB drones. The Hk allele 1 was more frequent in EHB drones compared with AHB (P LGT 0.01). However, the frequencies of the Mdh1 allele in EHB drones from Yucatan was intermediate between AHB and EHB drones from an Africanized-free zone (P LGT 0.01). These results suggest that, for Yucatecan populations, Hk is more informative concerning the African or European origin of drones than Mdh. Evidence of undetected levels of africanization with morphometrics alone and the non-neutrality and high within-population variation of the Mdh loci make the use of these techniques questionable as a diagnostic of africanization in drones from the Yucatan. The use of Hk in combination with mitochondrial and/or nuclear DNA markers would be of more value to analyse the dynamics of male production, seasonal abundance and male releases in drone congregation areas in Yucatan.

Worker honeybees (Apis mellifera capensis) encapsulate the small hive beetle (Aethina tumida), a nest parasite, in propolis (tree resin collected by the bees). The encapsulation process lasts 1-4 days and the bees have a sophisticated guarding strategy for limiting the escape of beetles during encapsulation. Some encapsulated beetles died (4.9%) and a few escaped (1.6%). Encapsulation has probably evolved because the small hive beetle cannot easily be killed by the bees due to its hard exoskeleton and defensive behaviour.

During honeybee foraging, the stabilization of thoracic temperature (Tth) at elevated values is necessary to meet the power requirements of flight at different air temperatures (Ta). To understand how the bee achieves thermal stability at different reward rates, the metabolic rates of undisturbed foraging bees were measured at different Ta values and different sucrose solution flow rates. Metabolic heat production, calculated from the rate of carbon dioxide production, decreased linearly from 49.7 to 23.4 mW as Ta increased from 19 to 29degreeC (sucrose flow rate 1.75 mul min-1, 50% w/w). In contrast, crop load and inspection rate remained constant. Metabolic rate displayed a linear relationship with both Ta and the logarithm of the flow rate of sucrose solution (range analyzed 0.44-13.1 mul min-1, 50% w/w). Metabolic rate decreased by 3.13+ -0.52 mW (mean+-S.E.M., N=37) for every 1degreeC increase in Ta and increased by 4.36+-1.13 mW for a doubling in flow rate. These changes in metabolic power output might be used to achieve thermal stability during foraging. It is suggested that the foraging bee might increase its Tth in accordance with the reward rate.

In order to evaluate the best period to collect royal jelly (RJ) from queen cells and study the larval development of Apis mellifera, RJ production and larval weight (LW) were analyzed in Ibimirim and Petrolandia, counties of the semi-arid region of Pernambuco, Brazil. The study was performed in May and June, 1995 and the experimental design was randomized blocks. The RJ collected and the LW after 24, 32, 48, 58 and 72 h in relation to larval transfer period were significantly different (P LGT 0.01) in both locations. Regression equations showed that maximum productions of RJ, 157.57 mg in (Ibimirim) and 183.69 mg in (Petrolandia) were achieved, respectively at 59 and 54 h after larval transference. The results show the best production could be obtained by collecting RJ between 48 and 56 h after larval transfer in both locations.

The pollination effectiveness of the commercially reared bumble bee Bombus impatiens Cresson, was compared in field studies to the honey bee, Apis mellifera L., for lowbush blueberry, Vaccinium angustifolium Ait. A preliminary study indicated that B. impatiens had potential as an alternative pollinator. In a 3-yr study, percentage fruit set, percentage harvested berries, berry weight, and seeds per berry were compared in blueberry fields stocked at 7.5 A. mellifera hives per hectare to 5, 7.5, or 10 B. impatiens colonies per hectare. Percentage of harvested berries (yield) was significantly higher in fields stocked with B. impatiens at 10 colonies per hectare. No other parameters measuring pollinator effectiveness were significantly different at 5, 7.5, or 10 colonies per hectare. Flower handling time was significantly faster for B. impatiens and it more frequently collected blueberry pollen. All parameters of pollinator effectiveness were similar for B. impatiens, A. mellifera, and native wild bees in a follow-up study. Overall, B. impatiens was a suitable alternative to A. mellifera.

We compared the European honeybee races Apis mellifera armeniaca, A.m. caucasica, A.m. cypria, and A.m. syriaca. These subspecies are endemic to very different habitats. Additionally, they are exposed to very different levels of predation. A.m. caucasica exists where honeybee predators typically are rare, while the remaining subspecies have ranges that coincide with areas where honeybee predators are abundant. Foraging decisions of workers visiting artificial flower patches containing blue, white, and yellow flowers were recorded. We tested whether foragers responded to differences in rewarding flower frequency among flower color morphs. Division of labor occurred among foragers of each race; some bees frequented yellow flowers while other bees from the same hive visited blue and white flowers. A.m. caucasica foragers ignored differences in reward frequency among flower colors. Even bees that frequented blue and white flowers did not base flower choice on reward frequency differences between just these two color morphs. In contrast, A.m. armeniaca, A.m. cypria, and A.m. syriaca, however, did respond to differences in reward frequencies, tending to avoid the less frequently rewarding flower color morph. A.m. armeniaca forager division of labor (foragers committed to yellow or to blue and white flowers) was dominant to energy maximization. The reverse was true for A.m. cypria.

Two different hive entrance dead-bee traps designed using standard beekeeping materials were compared to assess their usefulness in determining honey bee (Apis mellifera) mortality. Two trials were carried out on 10 modified Langstroth hives in February and April, 1998, with two simple traps distributed randomly among colonies. In trial 1, five hives were tested with a modified pollen collector trap and the other five with an 'underbasket' trap. In trial 2, the same hives were used but with different traps. The strength of each colony was measured by counting the spaces between frames occupied by bees. On day 0, 100 dead marked bees were introduced into each hive and trapped bees were counted periodically. More than 91% of the dead bees were collected in both traps with similar results. No relationship was established between efficacy and the strength of the colony, but there was a relationship between efficacy and collection time. There was a direct relationship between the number of spaces between frames full of bees and the time of recovering dead bees. Both traps tested seem to provide an economical and simple way to assess bee mortality in a short-term test.

This research examined the effects of comb age on honey bee colony growth and brood survivorship. Experimental old combs were of an unknown age, but were dark and heavy as typical of combs one or more years old. New combs were produced just prior to the beginning of the experiment and had never had brood previously reared in them. Either old or new combs were installed into each of 21-24 nucleus colonies each year over a three-year period. On average, colonies with new comb produced a greater area (cm2) of brood, a greater area (cm2) of sealed brood, and a higher weight of individual young bees (mg). Brood survivorship was the only variable significantly higher in old comb.

To provide replicate samples of local bee populations in a nature preserve, light traps operated continuously on Barro Colorado Island (BCI), Panama, collected bees for 17 years, including 10 years following invasion by African Apis mellifera. Honey bees appeared in light traps as the first swarms colonized the Panama Canal area. Their numbers followed seasonal trends shown in independent studies, thus indicating bee abundance and activity in a large area. No measurable population-level impact of competition between this invading honey bee and native bees, despite many demonstrations of resource competition at flower patch and colony levels, changed annual abundances of all 15 native bee species. Native bee abundance did not decrease, nor did native bees show substantial reciprocal yearly change with honey bee abundance. One strong negative correlation of bee catches with an extremely rainy year was found. However, multiple regression using rainfall and honey bee abundance as the independent variables showed that neither was responsible for bee population change over 17 years. Nearly half the native species declined during a year that displayed peak honey bee number. That competition from honey bees on an island the size of BCI was necessarily reduced below impact levels expected on the mainland is discussed using a model of resource and consumer density, foraging range, and island size.

Hygienic behaviour forms one of the bases of tolerance of the Asian honey bee (Apis cerana) to varroa. This behaviour can also play an important role in the tolerance of the European honey bee (A. mellifera) towards the mite. The hygienic behavioural response of bees over a period of 24 h towards worker brood cells of A. mellifera iberica artificially infested with varroa was studied. When bees detected cells containing mites, in some instances both brood and mites were removed, whereas in others only the mite was removed. When a single mite was placed in each cell, hygienic behaviour was not induced, only 0.74% of infested cells had mites removed. Using two or three mites per cell, this response increased significantly, with 8.01% and 16.62% of infested cells with mites removed, respectively. A positive correlation (P LGT 0.05, r = 0.49) was found in hygienic behaviour towards cells artificially infested with two or three mites. A second experiment was conducted to compare the response of bees to live or dead mites inoculated into the cells. When three mites were placed in each cell, no difference in response to dead or live mites was observed (P = 0.686).

Honey bees satisfy their lipid requirement by consuming pollen. The free fatty acid content of the midgut was used to quantify fat digestion. Midguts extracted from younger workers of known ages and from foragers were divided into three components: endoperitrophic region (peritrophic membrane with gut contents), extraperitrophic region and intestinal wall. Both the total amount of pollen and the amount of free fatty acids in the endoperitrophic region and in the intestinal wall depend on the bee's age. The amounts increase within the 1st 3 days of a honey bee's life, reach maxima around the age of 8 days and then decrease continuously to the lowest values, measured in forager bees. Forced feeding with triacylglycerol results in significantly higher levels of free fatty acids, especially in the endoperitrophic region, in 8-day-old bees and foragers. This indicates that lipolytic activity depends on age and that the free fatty acid content in 8-day-old bees is primarily limited by the amount and availability of lipids ingested. The results show further that fat digestion depends on the functional status of honey bees, as is the case for pollen consumption, speed of transport of pollen bolus through the alimentary canal and protein digestion.

The objective of this study was to determine if nicotinic receptor antagonists known for their ability to impair memory in the honeybee could induce changes in brain metabolism. We tested the effect of antagonists (hexamethonium, mecamylamine, alpha-bungarotoxin (alpha-BTX)) and agonist (nicotine) brain injections on cytochrome oxidase (CO) histochemistry. Within as little as 30 min following nicotine injection, an increase of the staining was observed in almost all the structures analyzed. The increase was limited to the alpha-lobe after alpha-BTX injection. In contrast, the antagonists hexamethonium and mecamylamine reduced CO staining in this structure that seems to be involved in information retrieval. These results suggest that the decrease of metabolism in the alpha-lobe obtained with hexamethonium and mecamylamine injections could be related to the impairment of retrieval-processes previously observed with these drugs.

Hymenoptera attach to smooth surfaces with a flexible pad, the arolium, between the claws. Here we investigate its movement in Asian weaver ants (Oecophylla smaragdina) and honeybees (Apis mellifera). When ants run upside down on a smooth surface, the arolium is unfolded and folded back with each step. Its extension is strictly coupled with the retraction of the claws. Experimental pull on the claw-flexor tendon revealed that the claw-flexor muscle not only retracts the claws, but also moves the arolium. The elicited arolium movement comprises (i) about a 90degree rotation (extension) mediated by the interaction of the two rigid pretarsal sclerites arcus and manubrium and (ii) a lateral expansion and increase in volume. In severed legs of O. smaragdina ants, an increase in hemolymph pressure of 15 kPa was sufficient to inflate the arolium to its full size. Apart from being actively extended, an arolium in contact also can unfold passively when the leg is subject to a pull toward the body. We propose a combined mechanical-hydraulic model for arolium movement: (i) the arolium is engaged by the action of the unguitractor, which mechanically extends the arolium; (ii) compression of the arolium gland reservoir pumps liquid into the arolium; (iii) arolia partly in contact with the surface are unfolded passively when the legs are pulled toward the body; and (iv) the arolium deflates and moves back to its default position by elastic recoil of the cuticle.

We studied possible host finding and resistance mechanisms of host colonies in the context of social parasitism by Cape honeybee (Apis mellifera capensis) workers. Workers often join neighboring colonies by drifting, but long-range drifting (dispersal) to colonies far away from the maternal nests also rarely occurs. We tested the impact of queenstate and taxon of mother and host colonies on drifting and dispersing of workers and on the hosting of these workers in A. m. capensis, A. m. scutellata, and their natural hybrids. Workers were paint-marked according to colony and reintroduced into their queenright or queenless mother colonies. After 10 days, 579 out of 12,034 labeled workers were recaptured in foreign colonies. We found that drifting and dispersing represent different behaviors, which were differently affected by taxon and queenstate of both mother and host colonies. Hybrid workers drifted more often than A. m. capensis and A. m. scutellata. However, A. m. capensis workers dispersed more often than A. m. scutellata and the hybrids combined, and A. m. scutellata workers also dispersed more frequently than the hybrids. Dispersers from queenright A. m. capensis colonies were more often found in queenless host colonies and vice versa, indicating active host searching and/or a queenstate-discriminating guarding mechanism. Our data show that A. m. capensis workers disperse significantly more often than other races of A. mellifera, suggesting that dispersing represents a host finding mechanism. The lack of dispersal in hybrids and different hosting mechanisms of foreign workers by hybrid colonies may also be responsible for the stability of the natural hybrid zone between A. m. capensis and A. m. scutellata.

Body size in animals influences survival, fecundity, and mating opportunity. For bees, parental provisioning behavior largely controls offspring body size. Because larger offspring of many bee species have fitness advantages, selection on body size should act through selection on parental provisioning behavior and restrict body size variation of each species. Many bee species show great variability in body size, however, which may indicate that adult females are often constrained in their ability to consistently produce large offspring. We compared body size variation within bee species for two life history traits that could influence offspring body size: dietary breadth (specialist or generalist) and nesting habit (ground-nesting or cavity-nesting). We determined the head width (a reliable correlate of body size) of 2276 bees belonging to 31 bee species from five families and calculated the body size variation for each species. Body size variation, measured as the coefficient of variation in head size, did not differ between pollen specialists (oligoleges) and pollen generalists (polyleges) across 13 pairs of closely -related, sympatric bee species of similar body size. Cavity-nesting species showed significantly greater variation in body size than ground -nesting species, which suggests that the choice of nest cavities utilized may be a more important predictor of offspring body size than parental body size. The cleptoparasite Coelioxys sayi had similar body size variation to one of its hosts, Megachile brevis. The European honey bee, Apis mellifera, showed the least body size variation of any species measured.

It is well documented that several pharmacological substances are released within the victim's body after snakebite. These substances are also believed to be endogenously present in animals, specifically levels of myoglobin and histamine that are reported to rise after envenomation. However, there is no published data regarding the presence of these substances in venoms per se.This research reports the detection of myoglobin and histamine in snake, scorpion, honeybee, and toad venoms by immunological test. It is unlikely that the rise in levels of myoglobin and histamine is due to that added from the bite, since a single toxin devoid of such components is capable of elevating levels of these substances. Nonetheless, it is likely that the rise in levels of myoglobin and histamine after envenomation is due to the venom or toxin reacting with cells of various organs of the victim. Therefore, this phenomenon can be compared to cancer markers, which are endogenously present in humans at low levels and elevated in cancerous states.

Recently, propolis has been attracting the attention of researchers due to various biological activities and therapeutic properties. In Brazil, propolis is produced all year long, so there may be some seasonal variations. This work was carried out in order to compare propolis collected during the four seasons by its in vitro antimicrobial activity on yeast pathogens isolated from human infections. Propolis was produced by africanized honeybees in Botucatu, Sao Paulo State, collected throughout a year and pooled by season. Hydroalcoholic solutions of propolis were prepared with each pool and diluted in agar, using serial concentrations of propolis from each pool. A determination of minimal inhibitory concentration (MIC) was performed. The results show that Candida tropicalis and Candida albicans were susceptible to low concentrations of propolis, the latter showing a higher susceptibility. No differences were seen in relation to seasonal effects in the minimal inhibitory concentration of propolis.

Laboratory bioassays were conducted to evaluate neem oil and neem extract for the management of key honey bee (Apis mellifera L.) pests. Neem pesticides inhibited the growth of Paenibacillus larvae (Ash, Priest AMPERSAND Collins) in vitro but had no effect on the growth of Ascophaera apis (Olive AMPERSAND Spiltoir). Azadirachtin-rich extract (neem-aza) was 10 times more potent than crude neem oil (neem oil) against P. larvae suggesting that azadirachtin is a main antibiotic component in neem. Neem-aza, however, was ineffective at controlling the honey bee mite parasites Varroa jacobsoni (Ouduemans) and Acarapis woodi (Rennie). Honey bees also were deterred from feeding on sucrose syrup containing RGT 0.01 mg/ml of neem-aza. However, neem oil applied topically to infested bees in the laboratory proved highly effective against both mite species. Approximately 50-90% V. jacobsoni mortality was observed 48 h after treatment with associated bee mortality lower than 10%. Although topically applied neem oil did not result in direct A. woodi mortality, it offered significant protection of bees from infestation by A. woodi. Other vegetable and petroleum-based oils also offered selective control of honey bee mites, suggesting neem oil has both a physical and a toxicological mode of action. Although oils are not as selective as the V. jacobsoni acaricide tau-fluvalinate, they nonetheless hold promise for the simultaneous management of several honey bee pests.

A laboratory bioassay was developed to evaluate miticides to control Varroa jacobsoni (Oudemans), an important parasite of the honey bee, Apis mellifera L. Bees and mites were exposed to applications of essential oil constituents in petri dishes (60 by 20 mm). The registered mite control agents tau-fluvalinate (Apistan) and formic acid also were evaluated as positive controls. Treatments that caused high mite mortality ( RGT 70%) at doses that produced low bee mortality ( LGT 30%) were considered mite selective. The six most selective of the 22 treatments tested (clove oil, benzyl acetate, thymol, carvacrol, methyl salicylate, and Magic3) were further evaluated to estimate LD50 values and selectivity ratios (A. mellifera LD50/V. jacobsoni LD50) at 24, 43, and 67 h after exposure. Tau -fluvalinate was the most selective treatment, but thymol, clove oil, Magic3, and methyl salicylate demonstrated selectivity equal to or greater than formic acid. The effect of mode of application (complete exposure versus vapor only) on bee and mite mortality was assessed for thymol, clove oil, and Magic3 by using a 2-chambered dish design. Estimated V. jacobsoni LD50 values were significantly lower for complete exposure applications of thymol amd Magic3, suggesting that both vapor and topical exposure influenced mite mortality, whereas estimated values for clove oil suggested that topical exposure had little or no influence on mite mortality. These results indicate that essential oil constituents alone may not be selective enough to control Varroa under all conditions, but could be a useful component of an integrated pest management approach to parasitic mite management in honey bee colonies.

The small hive beetle Aethina tumida Murray (Coleoptera: Nitidulidae) is a new pest which has attacked honeybees (Apis mellifera) in the USA since 1998. A. tumida is a native of tropical and subtropical Africa where it attacks weakened colonies and A. m. scutellata and A. m. capensis storage combs. The beetles invade bee colonies and lay eggs inside them. Both larvae and adults feed on brood, pollen, wax, honey, and damage both the brood and honeycomb. When small hive beetle infestations are heavy and even if the colony is strong, queens will stop laying eggs and the bees often leave the hive. Mature larvae enter soil to pupate. The duration from egg to adult is about 38-81 days. Ensuring sanitary conditions in the hives and bee colony is the first line of defence against the small hive beetle. Coumaphos bee strips have been approved for use in hives in order to control the A. tumida. Fumigation of stored combs with p -dichlorobenzene is recommended and provides sufficient control.

Varroosis has not been widely studied in Venezuela, despite the damage that it causes for local beekeeping. Most beekeepers are not informed about management techniques for control and quite often they use incorrect methodologies, including appliation of organophosphate pesticides. The object of this research was to determine if Africanized bees were tolerant of this pest, and if with good management they could produce honey, despite the presence of Varroa jacobsoni. Chemical treatments were also tested. Four treatments (T1 = control, T2 = Bayvarol(R), T3 = Apistan(R) and T4 = Formic Acid) were applied during 10 weeks. Annual honey production yields were statistically similar for the four treatments (50.4, 49.8, 51.7 and 52.5 kg/colony, respectively for T1-4). The number of mites found dead on the bottom board was significantly higher for treatments 2-4, than in the control. Africanized honey bees appear to be tolerant of varroa, and can produce normal honey crops without the costs and risks of chemical treatments.

The three-dimensional solution structure of BSTI, a trypsin inhibitor from the European frog Bombina bombina, has been solved using 1H NMR spectroscopy. The 60 amino acid protein contains five disulfide bonds, which were unambiguously determined to be Cys (4-38), Cys (13-34), Cys (17 -30), Cys (21-60), and Cys (40-54) by experimental restraints and subsequent structure calculations. The main elements of secondary structure are four beta-strands, arranged as two small antiparallel beta -sheets. The overall fold of BSTI is disk shaped and is characterized by the lack of a hydrophobic core. The presumed active site is located on a loop comprising residues 21-34, which is a relatively disordered region similar to that seen in many other protease inhibitors. However, the overall fold is different to other known protease inhibitors with the exception of a small family of inhibitors isolated from nematodes of the family Ascaris and recently also from the haemolymph of Apis mellifera. BSTI may thus be classified as a new member of this recently discovered family of protease inhibitors.

The experiment was planned to study the insecticidal mortality, foraging behaviour and role of honeybees, Brassica campestris L. on Brassica, Apis mellifera L. during 1996-97. The application of insecticides (Polo 500 EC Primor 50 W) each @ 617.50 ml/ha was done only once under caged plot environment of 4X5X6 feet area. Twenty five individuals of honey bees were released in each treatment at 0, 24, 48, 72, 96 and 120 hours after insecticide application. For foraging behaviour, number of honeybees' visits per 10 minutes per flower on alternate days during January and February were recorded. Role of honeybees towards pollination was observed by recording seed yield, 1000 grain weight and by testing germination percentage of the seed of Brassica. For these studies, 1st caged plot was meant to be pollinated only by honey bees, 2nd caged plot to be pollinated only by wind and 3rd was kept open, as control (Honeybees + Wind + Other pollinators). Polo proved as a safer insecticide showing minimum mortality of honeybees as compared to Primor at all the post treatment intervals. The mortality, however, ranged from 4.00 to 9.00 as against 9.67-24.67 per 25 individuals in case of Polo and Primor, respectively. The maximum average number of visits of worker honeybees was recorded during 1000-1100 hours (25.21/flower/10 minutes) followed by the rest of the individuals in a day. The honeybees proved a good source of pollination, resulting a maximum seed yield (19.90 Q/ha.), maximum 1000 grain seed yield (3.813 gm) and maximum germination percentage (95.80%). Thus seed pollinated by honeybees was found to be healthy and of good quality.

Two generations of honey bees, Apis mellifera L., selected for resistance to tracheal mites, Acarapis woodi (Rennie), were produced from a foundation stock. The mite resistant lines had significantly low mite abundances and prevalences in each selected generation. The high mite -resistant lines of the first selected generation showed resistance equal to that of bees that had undergone natural selection from tracheal mite infestations for 3 yr in New York. Additionally, the high mite-resistant lines of the second selected generation and Buckfast bees had significantly lower mite abundances and prevalences than honey bees from control colonies which had never been exposed to tracheal mite infestation in Ontario. These results corroborate studies that have shown that honey bees possess genetic components for tracheal mite resistance that can be readily enhanced in a breeding program. The two methods used for evaluating relative resistance of honey bees to tracheal mites, a short -term bioassay and evaluation in field colonies, were positively correlated (rs = 0.64, P LGT 0.001).

Honey bee (Apis mellifera L.) colonies bred for hygienic behavior were tested in a large field trial to determine if they were able to resist the parasitic mite Varroa destructor better than unselected colonies of "Starline" stock. Colonies bred for hygienic behavior are able to detect, uncap, and remove experimentally infested brood from the nest, although the extent to which the behavior actually reduces the overall mite-load in untreated, naturally infested colonies needed further verification. The results indicate that hygienic colonies with queens mated naturally to unselected drones had significantly fewer mites on adult bees and within worker brood cells than Starline colonies for up to 1 yr without treatment in a commercial, migratory beekeeping operation. Hygienic colonies actively defended themselves against the mites when mite levels were relatively low. At high mite infestations ( RGT 15% of worker brood and of adult bees), the majority of hygienic colonies required treatment to prevent collapse. Overall, the hygienic colonies had similar adult populations and brood areas, produced as much honey, and had less brood disease than the Starline colonies. Thus, honey bees bred for hygienic behavior performed as well if not better than other commercial lines of bees and maintained lower mite loads for up to one year without treatment.

Laboratory studies were conducted to assess tomato, Lycopersicon esculentum Mill. (Solanaceae), quality in relation to the level of buzz-pollination by bumble bees. Studies were conducted in commercial tomato greenhouses in the Leamington, Ontario, area to categorize bruising of tomato anther cones by bumble bees into five levels of bruising. The number of pollen grains per stigma was determined for each bruising level, and the bruising level was found to be a good predictor of stigmatic pollen load. Experimental flowers were pollinated by bumble bees and assigned to bruising levels based on the degree of anther cone discoloration. Fruit set, tomato weight, minimum diameter, the number of days until ripe, roundness, weight, percentage sugars, and number of seeds were assessed and compared among bruising level. Fruit set in flowers receiving no pollination visits was 30.2%, whereas, 83.3, 84.4, 81.2, and 100% of the flowers set fruit in bruising levels 1, 2, 3, and 4, respectively. Minimum diameter, number of seeds, and tomato weight all increased from no bruising to different levels of bruising. There was no increase in weight or diameter above a bruising level of 1, and no increase in the number of seeds per fruit after a bruising level of 2. We found that pollination of tomato flowers greater than a bruising level of 2 (corresponding to approximately one to two bee visits) did not result in a significant increase in quality.

A study of sunflower, Helianthus annuus L., pollen collection by Africanized and European honey bees, Apis mellifera L., was conducted in a hybrid seed production field in Argentina. Africanized honey bees collected significantly larger proportions of sunflower pollen than did European honey bees. The result suggests that Africanized bees would be more efficient for commercial sunflower seed production.

Melittin is known as a phospholipase A2 (PLA2) activator, but the selectivity of its effect on PLA2 is uncertain. We examined the selectivity of melittin effect on the release of free fatty acids (FFAs) from L1210 cells using various inhibitors. A systemic lipid analysis by HPLC and GLC revealed that melittin induced release of various FFAs including saturated, monounsaturated, and polyunsaturated FFAs. Various PLA2 inhibitors examined exerted only minimal effects on the melittin -induced arachidonic acid (AA) and palmitic acid (PAL) releases. Specific inhibitors of phosphatidylinositol-phospholipase C (U73122) and diacylglycerol lipase (RHC80267) exerted significant inhibitory effects on both AA and PAL releases. These results suggest that melittin-induced FFA release is most likely due to multiple participations of various types of lipases. Since BAPTA/AM, an intracellular Ca2+ chelator, did not influence the FFA release, the Ca2+ influxed by melittin appeared not to be a key factor for the FFA release. The mimicking of the melittin-induced FFA release by digitonin, a membrane-permeabilizing agent, implies that the membrane-perturbing action of melittin is likely the cause of the FFA release. Melittin also induced release of multiple FFAs from other cell lines including P388D1 and HL60. The rapid melittin-stimulated phospholipase D (PLD) observed in L1210 cells appeared not directly related to the steady release of FFA, as indicated by the fact that the PLD was not blocked by RHC80267. In view of melittin's multiple effects on the composition of cellular lipids, we conclude that melittin does neither exclusively release any single FFA nor selectively activate PLA2 in L1210 cells. The problem of using melittin as a PLA2 activator is discussed.

A new hypertrehalosaemic peptide (Tea-HrTH; pQLNFSTGWGG-NH2) was isolated from the corpora cardiaca (CC) of the sawfly Tenthredo arcuata. The hypertrehalosaemic peptides found in the CC of five Bombus species and the paper wasp Polistes fuscata were identical to the adipokinetic hormone II of the desert locust, Schistocerca gregaria (Scg-AKH-II). The hypertrehalosaemic peptides found in the yellowjacket Vespula vulgaris and the hornet Vespa crabro were identical to the adipokinetic hormone of the cricket, Gryllus bimaculatus (Grb-AKH). All species examined had a large storage crop which, when filled with honey, held up to one-third of their total body weight. Overwintering queens of P. fuscata had large stores of carbohydrates and lipids in the abdomen, and were able to survive months of fasting. Workers of Bombus hortorum (bumble-bee), Apis mellifera (honey -bee) and V. vulgaris had little or no fat body. These species could fly as long as sugar was present in' their crops, but they stopped flying as the carbohydrates in the crop disappeared. There was no significant increase in the haemolymph carbohydrate titres after injections of CC extracts or corresponding synthetic peptides into workers of B. hortorum or into males and females of T. arcuata. There was a moderate increase in haemolymph carbohydrate titres when these peptides were injected into overwintering queens of P. fuscata and into workers of V. crabro, both with significant amounts of fat body. However, well-fed V. vulgaris workers, with very little fat body, also responded to their own hypertrehalosaemic peptide.

This study views a honey bee swarm as a supraorganismal entity which has been shaped by natural selection to be skilled at choosing a future home site. Prior studies of this decision-making process indicate that swarms attempt to use the best-of-N decision rule: sample some number (N) of alternatives and then select the best one. We tested how well swarms implement this decision rule by presenting them with an array of five nest boxes, only one of which was a high-quality (desirable) nest site; the other four were medium-quality (acceptable) sites. We found that swarms are reasonably good at carrying out the best-of-N decision rule: in four out of five trials, swarms selected the best site. In addition, we gained insights into how a swarm implements this decision rule. We found that when a scout bee returns to the swarm cluster and advertises a potential nest site with a waggle dance, she tunes the strength of her dance in relation to the quality of her site: the better the site, the stronger the dance. A dancing bee tunes her dance strength by adjusting the number of waggle-runs/dance, and she adjusts the number of waggle-runs/dance by changing both the duration and the rate of her waggle-run production. Moreover, we found that a dancing bee changes the rate of her waggle-run production by changing the mean duration of the return-phase portion of her dance circuits. Differences in return-phase duration underlie the impression that dances differ in liveliness. Although a honey bee swarm has bounded rationality (e.g., it lacks complete knowledge of the possible nesting sites), through its capacity for parallel processing it can choose a nest site without greatly reducing either the breadth or depth of its consideration of the alternative sites. Such thoroughness of information gathering and processing no doubt helps a swarm implement the best-of-N decision rule.

Investigations were carried out in Indo-Gangetic Plains to determine the influence of honeybees (Apis dorsata and A. mellifera) visitations on yield and quality of hybrid seed harvested from the eight sterile male rows individually in 1:8 (R:A) planting ratio in sunflower (Helianthus annuus L.) during the crop period of February to May, 1994 and 1995. The parental lines (R:MRH-1 and A:207A) of sunflower hybrid LSH-3 were maintained at a distance of 60 and 30 cm between and within rows, respectively. A significant (P LGT 0.05) variation was observed among the eight sterile male rows for the abundance of both the honeybee species, loose sunflower pollen grains/bee, pollination efficiency index (PEI) per bee, hybrid seed yield as well as its quality. Rows of sterile male parent which were in proximity (up to 5th row) to the male parent gave higher total hybrid seed yield/capitulum due to greater flow of pollens (r = 0.94) - as a result of higher bee abundance and increased PEI (r = 0.93). The number of unfilled seeds were also higher in capitulum harvested from these sterile male rows. In contrast, hybrid seed harvested from 6th, 7th and 8th row though produced less number of seeds/capitulum, due to poor bee abundance and lower PEI, yet had maximum number of filled and least unfilled seeds besides having maximum 100 seed weight. The quality of such seeds was also significantly better than those seeds harvested from sterile male rows raised adjacent to the fertile male parent. Utilization of hybrid seed harvested from various sterile male rows is discussed.

New formulations of formic acid and thymol, both individually and in combination with various essential oils, were compared with Apistan to determine their efficacy as fall treatments for control of Varroa jacobsoni (Oudemans), a parasitic mite of the honey bee, Apis mellifera L. Percent mite mortality in colonies treated with 300 ml of 65% formic acid averaged 94.2 +- 1.41% (least square means +- SE, n = 24), equivalent to those receiving four, 10% strips of Apistan (92.6 +- 1.79%, n = 6). Treatment with thymol (n = 24) resulted in an average mite mortality of 75.4 +- 5.79%, significantly less than that attained with Apistan or formic acid. The addition of essential oils did not affect treatment efficacy of either formic acid or thymol. The ratio of the coefficients of variation for percentage mortality for the formic acid (CVFA) and Apistan (CVA) groups was CVFA/CVA = 0.66. This indicates that the formic acid treatment was as consistent as the Apistan treatment. Thymol treatments did not provide as consistent results as Apistan or formic acid. Coefficient variation ratios for percentage mortality for the thymol group (CVT) with the Apistan and formic acid groups were CVT/CVA = 4.47 and CVT/CVFA = 6.76, respectively. In a second experiment, colonies received a 4-wk fall treatment of either 300 ml of 65% formic acid (n = 24) or four, 10% strips of Apistan (n = 6). The next spring, mite levels in the formic acid group (554.3 +- 150.20 mites) were similar to those in the Apistan treatment group (571.3 +- 145.05 mites) (P = 0.93). Additionally, the quantities of bees, brood, pollen, and nectar/honey in the two treatment groups were not significantly different (P gtoreq 0.50 each variable). These results suggest that formic acid is an effective alternative to Apistan as a fall treatment for varroa mites in temperate climates.

Varroa jacobsoni is an ectoparasite of Apis mellifera which invades brood cells, on 8-day-old larvae several hours before cell capping. Reproduction of the parasite takes place in the capped brood cells during the nymphose of the bee. Cuticular hydrocarbons of unparasitized bees and of bees parasitized by Varroa jacobsoni were extracted and analysed by gas chromatography (GC) coupled with mass spectrometry (GC-MS). Three developmental stages of worker honey bees were studied: larvae, pupae and emergent adults. The comparison between unparasitized and parasitized hosts was performed with Principal Components Analysis coupled with a multivariate variance analysis. The cuticular hydrocarbon profiles of honey bees were qualitatively similar, for the 3 developmental stages and regardless of the presence of Varroa in the cells. Nevertheless, comparison of the relative proportions of hydrocarbons showed that the cuticular profiles of pupae and emergent adults parasitized by 1 mite and of larvae parasitized by 2 mites were significantly different from the corresponding unparasitized individuals. Such modifications could be regarded (i) as a cause of the multi-infestation in larvae during invasion of brood and (ii) as a consequence of stress and/or removal of proteins contained in the haemolymph of the host during its development.

Inadequate bee pollination limits rabbiteye blueberry, Vaccinium ashei Reade, production in the some areas of the southeastern United States. Honey bees, Apis mellifera L., are currently the only manageable pollinators available for pollinating V. ashei. However, a new adaptable pollinator for rabbiteye blueberry, Osmia ribifloris Cockerell, was successfully reared and flown in captivity. The bee nested successfully in wooden shelters and conferred superior fruit set to 2-yr-old potted, rabbiteye blueberry bushes. Pollination efficiency or the percentage of blueberry flowers to set fruit after being visited once by a female O. ribifloris was comparable to that of the female blueberry bee Habropoda laboriosa (F.) and worker honey bees. Interestingly, honey bees once thought to be inefficient pollinators of rabbiteye blueberry were found to be very efficient, especially for 'Climax' and 'Premier' flowers.

Nine different genetic families of honey bees (Apis mellifera L.) were compared using summed z-scores (phenotypic values) and a modified selection index (Imod). Imod values incorporated both the phenotypic scores of the different traits and the economic weightings of these traits, as determined by a survey of commercial Ontario beekeepers. Largely because of the high weight all beekeepers place on honey production, a distinct difference between line rankings based on phenotypic scores and Imod scores was apparent, thereby emphasizing the need to properly weight the traits being evaluated to select bee stocks most valuable for beekeepers. Furthermore, when beekeepers who made RGT 10% of their income from queen and nucleus colony sales assigned relative values to the traits used in the Imod calculations, the results differed from those based on weightings assigned by honey producers. Our results underscore the difficulties the North American beekeeping industry must overcome to devise effective methods of evaluating colonies for breeding purposes.

The tendency of honey bees, Apis mellifera L, to become infested with tracheal mites, Acarapis woodi (Rennie), was measured in six different types of F1 colonies. The colonies were produced by mating a stock (Buckfast) known to resist mite infestation to each of five commercially available stocks and to a stock known to be susceptible to mites. Young uninfested bees from progeny and parent colonies were simultaneously exposed to mites in infested colonies, then retrieved and dissected to determine resultant mite infestations. Reduced infestations similar to but numerically greater than those of the resistant parent bees occurred in each of the six crosses made with resistant bees regardless of the relative susceptibility of the other parental stock. Reciprocal crosses between resistant and susceptible queens and drones proved equally effective in improving resistance. Therefore, allowing resistant stock queens to mate naturally with unselected drones, or nonresistant queens to mate with drones produced by pure or outcrossed resistant queens, can be used for improving resistance of production queens.

The proportion of Varroa jacobsoni Oudemans that were alive and mobile when they fell from honey bees, Apis mellifera L., in hives was measured during a 20-wk period to determine the potential use of systems that prevent these mites from returning to the bees. Traps designed to discriminate between the live, fallen mites and those that are dead or immobile were used on hive bottom boards. A large fraction of the fallen mites was alive when acaricide was not in use and also when fluvalinate or coumaphos treatments were in the hives. The live proportion of mitefall increased during very hot weather. The proportion of mitefall that was alive was higher at the rear and sides of the hive compared with that falling from center frames near the hive entrance. More sclerotized than callow mites were alive when they fell. A screen-covered trap that covers the entire hive bottom board requires a sticky barrier to retain all live mites. This trap or another method that prevents fallen, viable mites from returning to the hive is recommended as a part of an integrated control program. It also may slow the development of acaricide resistance in V. jacobsoni and allow the substitution of less hazardous chemicals for the acaricides currently in use.

Floral nectar characteristics of nine inbred lines of onion (Allium cepa L.) were examined to determine their influence on the attractiveness of the onion flowers to honey bees (Apis mellifera L.). Potassium concentrations and sugar concentrations of the nectar did not significantly correlate with the number of bee visits received by an umbel. The average amount of nectar produced by both the umbels and the individual florets was significantly positively correlated with the number of bee visits. Our results suggest that selection for flowers with high nectar production may lead to a higher rate of pollination of the onion seed crop.

This study was conducted to determine the existence of phenotypic and genotypic variation in the ability of honey bee colonies to restrain the population growth of the mite Varroa destructor Anderson and Trueman, and to assess the relative effect of four characteristics that may confer tolerance to honey bees toward the mite. Fifty-eight colonies infested with an equal number of mites were sampled monthly during six months to determine their levels of infestation on adult bees and in worker brood. At the end of this period, 16 colonies were selected to study the effect of grooming behavior, hygienic behavior, brood attractiveness, and host -induced non-reproduction. The infestation-levels in adult bees varied significantly between colonies (range: 6.6-44.7%), but no differences were found in the brood infestation levels. The variation between colonies was partially genetic in origin. Grooming behavior explained most of the variation (r2 = 0.38). Negative correlations were found between the mite population growth and both the total number of mites and the number of injured mites collected from the bottom-boards (r = -0.65 and r = -0.76, respectively). Differences were found for hygienic behavior but the effect of this mechanism was not clear. No differences were found among colonies for brood attractiveness, or for the effect of the brood on the mite's reproduction.

The task of nectar foraging in honey-bees is partitioned between foragers and receivers. Foragers typically transfer a nectar load in the nest as sub-loads to several receivers rather than as a single transfer. Foragers experience delays in finding receivers and use these delays to balance the number of foragers and receivers. A short delay results in the forager -recruiting waggle dance whereas a long delay results in the receiver -recruiting tremble dance. Several nectar transfers increase the cost of this system by introducing additional delays in finding extra receivers. We tested four hypotheses to explain the occurrence of multiple transfer. We found no evidence that multiple transfer is due to different crop capacities of foragers and receivers or that it results from extensive trophallactic interactions with nest-mates. Receiver bees frequently evaporate nectar in their mouthparts to hasten the production of honey. The suggestion has been made that multiple transfer is driven by receivers who take partial loads from foragers to enhance nectar evaporation. An alternative suggestion is that foragers drive multiple transfer to gain better information on the balance of foragers and receivers. Multiple sampling of the delay in finding a receiver reduces the standard deviation of the delay mean and so provides foragers with better information than is provided by a single delay. The enhanced-evaporation hypothesis predicts that receivers break foragers' first transfer whereas the information improvement hypothesis predicts foragers break their first transfers. Furthermore, only the information improvement hypothesis predicts a high level of multiple receptions. Data on transfer break-off and receiver behaviour strongly support the information improvement hypothesis and reject the enhanced-evaporation hypothesis. We suggest that multiple transfer is an adaptive sampling mechanism, which improves foragers' information on colony work allocation, and that multiple sampling is a common feature of social insect societies.

Honey bee co'lonies typically consist of about 20-40 thousand workers, zero to few thousand males (drones), depending on the time of year, and a single queen, the mother of the colony. Workers typically live 3-6 weeks during the spring and summer and can live about 4 months during the winter. Queens are longer lived. Anecdotes of queens living 2-3 years are not unusual, though they normally live less than a year in commercial hives. Little is known about the life span of drones. Queens develop from fertilized eggs that are not different from the eggs that develop into workers. Queens are, however, twice as large, have specialized anatomy, live much longer, and develop faster from egg to adult. All of these differences are derived from differences in larval rearing environment, primarily nutrition. The developmental trajectory of a female larva from worker into a queen can be determined as late as the third day of larval development, after this time the developmental pathway is fixed for a worker phenotype. The total time of larval development is only 5-6 days, therefore, just 2-3 days of differential feeding can lead to profound differences in development, and longevity. Workers undergo age development after they become adults. Workers usually initiate foraging behavior when they are 2-3 weeks old. The age at which a worker initiates foraging is a strong determinant of her length of life. This is presumed to be a result of the hazards of foraging, but natural senescence also occurs. Some bees remain in the nest and are never observed to forage, thereby outliving their forager sisters. Corresponding to this behavioral development are changes in the sizes of glands and the production of glandular products, increases in biogenic amine titers within the brain, an increase in the volume of specific regions of the brain, and changes in the neural system that affect perception of stimuli, and learning and memory. These age -related changes in behavior are regulated by intrinsic and extrinsic factors. Genetic variation has been demonstrated for many of these life history and behavioral traits. Selection and genome mapping studies have demonstrated relationships between the neural system, behavior, and life history traits.

Vitellogenic follicles of two insect species have been investigated in the electron microscope and with fluorescence technique. In the cotton bug Dysdercus intermedius (Distant 1902) broad intercellular spaces are present between the follicle cells, and these keep close contact among each other with a thick protuberance towards each neighbour. Long protrusions of the follicle cells reach through the broad perivitelline space and touch the surface of the oocyte. Between the microvilli on the surface of the oocyte an electron-dense material is found, which is taken up into the oocyte by endocytosis on the membrane of the microvilli, in between of them, and in infoldings of the oocyte membrane; in the interior of the oocyte this material is accumulated in big yolk spheres. In the honey bee Apis mellifera (Linnaeus 1758) only pore-like canals are found in the triangular corners formed by three follicle cells. Inside the cells these canals are associated with F-actin filaments. Apically the follicle cells protrude numerous, finger-like protrusions deep into the oocyte, which are densely filled with F-actin filaments. Endocytosis is seen on the surface of the oocyte between the short microvilli and along the surface pockets enclosing the follicle cell fingers. The two exampels show that in insects very different structures and mechanisms exist which may improve yolk uptake.

To determine general or species-specific properties in neural systems, it is necessary to use comparative data in evaluating experimental findings. Presented here are data on associative learning and memory formation in honeybees, emphasizing a comparative approach. We focus on four aspects: (1) the role of an identified neuron, VUMmx1, as a neural substrate of appetitive reinforcement; (2) the sequences of molecular events as they correlate with five forms of memory stages; (3) the localization of the memory traces following appetitive olfactory learning; and (4) the brief description of several forms of complex learning in bees (configuration in olfactory conditioning, categorization in visual feature learning, delayed matching-to-sample learning, and latent learning in navigation). VUMmx1 activity following the conditioned stimulus odor is sufficient to replace the unconditioned stimulus, and VUMmx1 changes its response properties during learning similarly to what is known from dopamine neurons in the basal ganglia of the mammalian brain. The transition from short- to mid- and long-term forms of memory can be related to specific activation of second messenger cascades (involving NOS, PKA, PKC, and PKM) resembling general features of neural plasticity at the cellular level. The particular time course of the various memory traces may be adapted to the behavioral context in which they are used; here, the foraging cycle of the bee. Memory traces for even such a simple form of learning as olfactory conditioning are multiple and distributed, involving first- and second -order sensory neuropils (antennal lobe and mushroom bodies), but with distinctly different properties. The wealth of complex forms of learning in the context of foraging indicates basic cognitive capacities based on rule extraction and context-dependent learning. It is believed that bees might be a useful model for studying cognitive faculties at a middle level of complexity.

Insects process and learn information flexibly to adapt to their environment. The honeybee Apis mellifera constitutes a traditional model for studying learning and memory at behavioural, cellular and molecular levels. Earlier studies focused on elementary associative and non -associative forms of learning determined by either olfactory conditioning of the proboscis extension reflex or the learning of visual stimuli in an operant context. However, research has indicated that bees are capable of cognitive performances that were thought to occur only in some vertebrate species. For example, honeybees can interpolate visual information, exhibit associative recall, categorize visual information and learn contextual information. Here we show that honeybees can form 'sameness' and 'difference' concepts. They learn to solve 'delayed matching-to -sample' tasks, in which they are required to respond to a matching stimulus, and 'delayed non-matching-to-sample' tasks, in which they are required to respond to a different stimulus; they can also transfer the learned rules to new stimuli of the same or a different sensory modality. Thus, not only can bees learn specific objects and their physical parameters, but they can also master abstract inter-relationships, such as sameness and difference.

In an appetitive context, honeybees (Apis mellifera) learn to associate odors with a reward of sucrose solution. If an odor is presented immediately before the sucrose, an elemental association is formed that enables the odor to release the proboscis extension response (PER). Olfactory conditioning of PER was used to study whether, beyond elemental associations, honeybees are able to process configural associations. Bees were trained in a positive and anegative patterning discrimination problem. In the first problem, single odorants were nonreinforced whereas the compound was reinforced. In the second problem, single odorants were reinforced whereas the compound was nonreinforced. We studied whether bees can solve these problems and whether the ratio between the number of presentations of the reinforced stimuli and the number of presentations of the nonreinforced stimuli affects discrimination. Honeybees differentiated reinforced and nonreinforced stimuli in positive and negative patterning discriminations. They thus can process configural associations. The variation of the ratio of reinforced to nonreinforced stimuli modulated the amount of differentiation. The assignment of singular codes to complex odor blends could be implemented at the neural level: When bees are stimulated with odor mixtures, the activation patterns evoked at the primary olfactory neuropile, the antennal lobe, may be combinations of the single odorant responses that are not necessarily fully additive.

The influence of the queen and her pheromonal signal on comb construction was examined. We tested four treatments with newly hived packages of bees containing: 1) a mated queen, 2) a virgin queen, 3) no queen but with a dispenser containing synthetic queen mandibular pheromone (QMP), and 4) no queen and no pheromone. After 10 days, the comb produced by each colony was removed, comb measurements made, bees from the comb-building area collected, the size of the scales on the wax mirrors of the collected bees ranked on a scale of 0-4 and the queens removed and analyzed for QMP components. Queenless workers built substantially less comb and the comb they did build had significantly larger, drone-sized cells than for the other 3 treatments, indicating that both cell size and the quantity of comb built are mediated through the queen, particularly QMP. The observations of wax scale size suggested that QMP influenced comb building behaviour rather than wax scale production. These results support the idea that queenless honey bees can adopt a strategy of constructing drone-sized cells in order to increase reproductive fitness through male production following queen loss.

We studied the pollination of Orchis boryi at five different locations on the Greek mainland. Orchis boryi is food deceptive and obligatorily insect pollinated. Primary pollinators were Apis mellifera and Bombus spp, which foraged on rewarding plant species nearby and visited O. boryi in between. To analyse floral colour similarity among rewarding plants and O. boryi as perceived by bees, a model of bee colour vision was employed. For each food plant an index was calculated that described the probability of a bee foraging on it to subsequently choose an orchid flower. This choice probability correlated to colour distance according to the model of bee colour vision, indicating that bees chose the deceptive orchid more frequently if they foraged on more similarly coloured species. At different sites different plant species served as models. Bees foraging on food plants from which a high choice rate to the orchid was observed visited the orchid less often after approaching it than other bees, which is likely to reflect avoidance learning. In general, the pollination syndrome appears to be a generalized form of Batesian mimicry, in which similarity to rewarding plants determines reproductive success. As expected by negative density-dependent selection, individual fruit set and pollinia export rate correlated negatively with orchid density, but were unaffected by food plant density, orchid frequency, individual variation of labellum colour, labellum size, or mouth width of the flowers.

1. Genetic polymorphisms of flowering plants can influence pollinator foraging but it is not known whether heritable foraging polymorphisms of pollinators influence their pollination efficacies. Honey bees Apis mellifera L. visit cranberry flowers for nectar but rarely for pollen when alternative preferred flowers grow nearby. 2. Cranberry flowers visited once by pollen-foraging honey bees received four-fold more stigmatic pollen than flowers visited by mere nectar-foragers (excluding nectar thieves). Manual greenhouse pollinations with fixed numbers of pollen tetrads (0, 2, 4, 8, 16, 32) achieved maximal fruit set with just eight pollen tetrads. Pollen-foraging honey bees yielded a calculated 63% more berries than equal numbers of non-thieving nectar-foragers, even though both classes of forager made stigmatic contact. 3. Colonies headed by queens of a pollen-hoarding genotype fielded significantly more pollen -foraging trips than standard commercial genotypes, as did hives fitted with permanently engaged pollen traps or colonies containing more larvae. Pollen-hoarding colonies together brought back twice as many cranberry pollen loads as control colonies, which was marginally significant despite marked daily variation in the proportion of collected pollen that was cranberry. 4. Caloric supplementation of matched, paired colonies failed to enhance pollen foraging despite the meagre nectar yields of individual cranberry flowers. 5. Heritable behavioural polymorphisms of the honey bee, such as pollen-hoarding, can enhance fruit and seed set by a floral host (e.g. cranberry), but only if more preferred pollen hosts are absent or rare. Otherwise, honey bees' broad polylecty, flight range, and daily idiosyncrasies in floral fidelity will obscure specific pollen-foraging differences at a given floral host, even among paired colonies in a seemingly uniform agricultural setting.

Eight Apis mellifera syriaca colonies at the Jordan University of Science and Technology campus in Jordan were used in the experiments to detect defence behaviour of worker bees against Varroa jacobsoni. This defence mechanism was determined by the degree of damaged mites that dropped from naturally infested colonies on inserts placed under the brood nest from June to October 1998. The average percentage of all dropping mites that were injured was 22.8%. A total of 86.5% of amputated mites were pigmented and 13.5% were less pigmented. Amputation to the first pair of legs was more often seen. Most of the phoretic mites were concealed between sclerites laterally on the abdomen, with distinct preference between second and third tergites. The grooming activity of A. mellifera syriaca provides evidence of active mechanisms of resistance toward the parasitic Varroa-mite.

An experiment on appropriate time of colony division and strength of divides in Apis mellifera L. bees was carried out at CCS Haryana Agricultural University, Hisar during autumn and spring seasons. On the basis of queen mating success and subsequent colony build up, it was concluded that the appropriate time for colony division during spring season is February/March and during autumn season November/December under agro-ecological conditions of Hisar (Haryana).

Honeybees must track changing distributions of food resources in their environment. We evaluated the genetic basis for interindividual differences in this ability by selecting lines of honeybees that differed in their tendency to reverse a learned discrimination between two odours. We show that individual variation in reversal learning performance, which is an analogue of natural foraging problems such as risk sensitivity, has a heritable component. Selection on drones, which are haploid, was sufficient to obtain a significant selection response after a single generation. In addition, worker age and/or task specialization, in terms of performance of housekeeping versus outside duties, is a source of environmental control over expression of reversal performance. Finally, we identified a correlated response in latent inhibition, in which pre -exposure to a conditioned stimulus (CS) retards learning about that CS when it is subsequently paired with reinforcement. From an ecological standpoint, our results suggest that colonies that contain a variety of genetic lineages may be able to target foragers to learning tasks in which they are genetically predisposed to do well.

The contraction of the isolated heart of the bee in physiological solution can be monitored for hours, making this preparation suitable for the investigation of the cardiotoxic action of certain compounds. The results of this study have shown that exposure of the semi-isolated heart of the bee to 1, 0.1, and 0.01 muM deltamethrin causes a temporal increase in the frequency and the force of spontaneously generated contractions, which is followed by a decrease in both parameters. The decrease is dose dependent. The action of deltamethrin was not reversible. The fungicide prochloraz applied at the same concentration levels as deltamethrin has an immediate chronotropic and inotropic effect on the semi-isolated heart of the bee, but its effects are more intense than those caused by deltamethrin. Comparison of the dose-response curves clearly shows that prochloraz is more cardiotoxic than deltamethrin. When prochloraz and deltamethrin are combine there is an increase of over 100 times in the cardiotoxicity of deltamethrin and an increase of 10 times in the toxicity of prochloraz. Our suggestion is that this synergistic action could be caused by the action of the two compounds on the same target site, which in the heart of the bee may be gap junctional intercellular communication, a vital physiological mechanism for the functioning of the heart in both vertebrates and invertebrates.

Three-years of study on the parasitic mite Varroa jacobsoni Oudemans attacking the honey bee was performed in Egypt. The objectives of this study were to: (1) estimate the level of mites infestation by using four diagnostic methods, i.e. analysis of hive debris, chemical diagnosis using Apistan strips, inspection of the sealed worker brood as well as mites attached to adult bees, and (2) evaluate the varrocidal effect of some natural products such as spearmint (dry matter and water extract), wormseed (dry matter, water extract and oil), camphor, lemon juice, sugar solution, and Apilife/Var (Italian mixture), in comparison to Apistan and formic acid (65 AMPERSAND 83 %) as chemical products.

Four species of mites (Acari) are recorded for the first time from beehives of Apis mellifera carnica, from Belgium, i.e. 1) Neocypholaelaps apicola Delfinado-Baker AMPERSAND Baker (1983) (Mesostigmata: Ameroseiidae); this species was, so far, only known from its typical host (Apus cerana) and locality (Pakistan). 2) Parasitellus fucorum (De Geer, 1778) (Mesostigmata : Parasitidae); this species had already been recorded from Bombus sp. from Belgium. 3) Hypoaspis sp. (Mesostigmata : Laelapidae). 4) Glycyphagus domesticus (De Geer, 1778) (Astigmata : Glycyphagidae).

In the honeybee the cAMP-dependent signal transduction cascade has been implicated in processes underlying learning and memory. The cAMP-dependent protein kinase (PKA) is the major mediator of cAMP action. To characterize the PKA system in the honeybee brain we cloned a homologue of a PKA catalytic subunit from the honeybee. The deduced amino acid sequence shows 80-94% identity with catalytic subunits of PKA from Drosophila melanogaster, Aplysia californica and mammals. The corresponding gene is predominantly expressed in the mushroom bodies, a structure that is involved in learning and memory processes. However, expression can also be found in the antennal and optic lobes. The level of expression varies within all three neuropiles.

Forager honey bees have higher brain levels of octopamine than do bees tending larvae in the hive. To test the hypothesis that octopamine influences honey bee division of labor we treated bees orally with octopamine or its immediate precursor tyramine and determined whether these treatments increased the probability of initiating foraging. Octopamine treatment significantly elevated levels of octopamine in the brain and caused a significant dose-dependent increase in the number of new foragers. This effect was seen for precocious foragers in single -cohort colonies and foragers in larger colonies with more typical age demographies. Tyramine treatment did not increase the number of new foragers, suggesting that octopamine was exerting a specific effect. Octopamine treatment was effective only when given to bees old enough to forage, i.e., older than 4 days of age. Treatment when bees were 1-3 days of age did not cause a significant increase in the number of new foragers when the bees reached the minimal foraging age. These results demonstrate that octopamine influences division of labor in honey bee colonies. We speculate that octopamine is acting in this context as a neuromodulator.

An apparatus is described for the study of classical conditioning of proboscis extension in harnessed honey bees, Apis mellifera L., that permits automatic programming of events and recording of data. The apparatus is easy to use, accommodates a wide range of stimuli and can be used to study both associative and nonassociative learning. The technique was evaluated in a series of experiments in which the performance of bees was compared under automated and traditional methods of conditioning. The results indicated that the automated apparatus can successfully be used to study Pavlovian conditioning, discrimination learning, and habituation. A unique finding was that the odor of honeycomb can serve as an unconditioned stimulus to support Pavlovian conditioning.

The thorax surface temperature of dancing honeybees (Apis mellifera carnica) recruiting nestmates to natural sources of nectar and pollen around Graz (Austria) was measured by real-time infrared thermography without touching them or disturbing social interactions. Thorax temperature during dancing was quite variable (31.4-43degreeC). In the course of a foraging season it varied considerably and was always lower than in bees foraging from a highly profitable food source (2 molar sucrose 120 m from the hive). It averaged 38.0degreeC (SD=2.24, n=224 dances) in the nectar foragers and 37.4degreeC (SD=1.64, n=171) in the pollen foragers, resembling that of dancers foraging 0.5 molar sucrose from feeders with unlimited flow. Hive air temperature accounted only for about 3-8% of total variation. Foraging distance modulated dancing temperature in a way that, according to the decrease of the profitability of foraging with distance, maximum temperatures decreased and, in accordance with the increase of the dancing threshold with distance, minumum temperatures increased with distance, this way providing new support for the hypothesis that the dancing temperature is modulated by the profitability of foraging and the dancing and foraging motivation of the bees. Dancing temperature of both nectar and pollen dancers correlated with several parameters of the hive status, increasing with the amount of brood and decreasing with the amount of honey and pollen. These correlations are discussed with respect to literature reports on a colony's need for pollen and nectar, in particular the effect of brood and the amount of pollen on pollen foraging, and the effect of honey stores and demand for nectar on nectar foraging.

To assess potential impacts of transgenic pest-resistant plants, newly -emerged adult honey bees from ten colonies were tagged, placed in cages at 33 degreeC, and fed with 625 mug/g CrylBa Bacillus thuringiensis (Bt) toxin or 2.5 mg/g aprotinin proteinase inhibitor in pollen-food (equivalent to 0.25% or 1% of total soluble protein). Control bees were given similar food without additive. All foods were consumed at similar rates. After seven days, all bees were returned to their hives. Subsequent observations showed that CrylBa-fed bees did not differ significantly from control bees in the timing of their first flight, the period during which flights took place or in estimated longevity. However, aprotinin-fed bees began to fly and also died about three days sooner than CrylBa-fed or control bees. Their flight periods were similar to those of the other bees. The effects of transgenic aprotinin-plants on honey bees will thus depend on gene expression levels in pollen.

The pollination system of Tricyrtis dilatata Nakai was investigated in the natural population of Anmyon Island (in the middle of the peninsular), Korea and the data from the natural population were compared with those of transplanted population in the Forest Research Institute located in Seoul. The various insects of 18 species, 7 families, 4 orders (mainly Hymeonoptera and Diptera) visited on the flowers of T. dilatata, and captured during the visitation. The most dominant and effective pollinators are Bumblebee (Bombus opulentus Smith), Leaf-cutter bees (Megachile spp.) and solitary mining bee (Amegilla florea Smith) and hover -fly (e.g., Allograpta balteata (de Geer)). In Anmyon Island population, the visitation frequency had a peak at 11-12 AM. The flowers of T. dilatata last for two days and they are protandrous. It is also confirmed that the flower of T. dilatata is autogamous (self-compatible), if no pollinator visit the flower, but the autogamy seems to be usually avoided by the pronounced protandry. It is confirmed that the pouch-like spur of each flower is well developed during the blooming, but the entrance of spur is so narrow that inefficient visitors can presumably be filtered effectively. The floral structures (pollen, microstructure of tepal, anther) of T. dilatata were described and discussed in connection with the pollination system. The conservation strategies (e.g., neighboring plants, the breeding place of pollinators, vegetation structure, etc.) of T. dilatata in the Korean population (in situ) were also briefly proposed.

Ectoparasitic mite Varroa jacobsoni (Oud.) distribution on Apis mellifera (L.) workers was studied. The mites demonstrated a significant preference for the left side of the 3rd and 4th ventro lateral abdominal tergites of the bees. Increased parasitic prevalence was recorded towards the end of the winter. During these months, a higher number of bees carrying 2 or more mites were observed. The position adopted by the mites allows them to reach the central portion of the intestine and thus have access to higher concentrations of nutrients. The results obtained emphasize the importance of applying effective control measures towards the end of the winter season.

In a greenhouse metabolism study, sunflowers were seed-treated with radiolabelled imidacloprid in a 700 g kg-1 WS formulation (Gaucho(R) WS 70) at 0.7 mg AI per seed, and the nature of the resulting residues in nectar and pollen was determined. Only the parent compound and no metabolites were detected in nectar and pollen of these seed-treated sunflower plants (limit of detection LGT 0.001 mg kg-1). In standard LD50 laboratory tests, imidacloprid showed high oral toxicity to honeybees (Apis mellifera), with LD50 values between 3.7 and 40.9 ng per bee, corresponding to a lethal food concentration between 0.14 and 1.57 mg kg -1. The residue level of imidacloprid in nectar and pollen of seed-treated sunflower plants in the field was negligible. Under field-growing conditions no residues were detected (limit of detection: 0.0015 mg kg-1) in either nectar or pollen. There were also no detectable residues in nectar and pollen of sunflowers planted as a succeeding crop in soils which previously had been cropped with imidacloprid seed-treated plants. Chronic feeding experiments with sunflower honey fortified with 0.002, 0.005, 0.010 and 0.020 mg kg-1 imidacloprid were conducted to assess potential long-term adverse effects on honeybee colonies. Testing end -points in this 39-day feeding study were mortality, feeding activity, wax/comb production, breeding performance and colony vitality. Even at the highest test concentration, imidacloprid showed no adverse effects on the development of the exposed bee colonies. This no-adverse-effect concentration of 0.020 mg kg-1 compares with a field residue level of less than 0.0015 mg kg-1 (= limit of detection in the field residue studies) which clearly shows that a sunflower seed dressing with imidacloprid poses no risk to honeybees. This conclusion is confirmed by observations made in more than 10 field studies and several tunnel tests.

American foulbrood is a fatal disease of honeybee larvae. Larvae become infected by swallowing spores of P. larvae larvae that contaminate their food. Adult bees who transfer the spores and have close contact with larvae never become infected. Resistance to this bacterium was investigated in various larval stages and in adults of different ages. Substances inhibiting the growth of P. larvae larvae could be demonstrated in 4 day old larvae and, to a lesser extent, in 1 day old larvae. No such substances could be shown in 6 day old larvae. Extracts of midguts of adult bees generally showed a stronger ability to inhibit growth of the bacteria than did extracts of larvae. It was discovered that the midguts of 8 day old adult bees show a higher growth-inhibiting potential against P. larvae larvae than midguts of freshly emerged adult bees or foragers.

Four aminopeptidases were detected in Apis mellifera by starch gel electrophoresis. These enzymes were characterized on the basis of their substrate preference, effect of inhibitors, tissue and ontogenetic developmental distribution. Lap-A activity was present at all tissues and developmental stages. Lap-P was characterized by a more intense activity during the pupal stage. Lap-G activity was concentrated in the midgut and was detected in association with the presence of food inside the digestive tract. Lap-D was more proeminent in the reproductive tract of adult drones, where its activity appeared to be concentrated in the mucus. Four electrophoretic variants of Lap-D were observed, with an uncommonly high intralocus heterozygosity level. Segregational analyses demonstrated the absence of close linkage between Lap-D and Est-1a, Est-2, Est-5, Est-6, Mdh-1, Hk-1 and Pgm-1 loci of Apis mellifera.

The ectoparasitic mite Varroa jacobsoni poses a major threat to the survival of European honey-bee populations. Development of effective control methods is therefore much needed. Study of interspecific chemical communication between the parasite and host is a particularly promising avenue of research. Previous study has shown that the cuticular hydrocarbons of the parasite mite Varroa jacobsoni are qualitatively identical to those of its honey-bee host Apis mellifera (Nation J.L., Sanford M.T., Milne K., 1992. Cuticular hydrocarbons from Varroa jacobsoni. Experimental and Applied Acarology 16, 331-344). The purpose of the present study was to compare the cuticular hydrocarbon patterns of the two species at different stages of bee development. Cuticular components were identified by gas chromatography/mass spectrometry. The proportion of each component was calculated at three stages of bee development (larvae, pupa, emerging bee). The degree of chemical mimicry between the parasite and host was evaluated by multivariate analyses using the resulting proportions for each category of individuals. There were four main findings. The first was that the proportions of some components are different at the larval, pupal and imago stage of bee development. Second, Varroa profiles vary depending on the developmental stage of the host. Third, the cuticular profile of adult mites is more similar to that of the stage of the host than that of later and/or earlier stages except for parasites collected from emerging adult bees. Fourth, the degree of mimicry by Varroa is greater during larval and pupal stages than during the emerging adult bee stages. The role of chemical mimicry - although it is not perfect - in enabling parasites to infest bee colonies by the parasite is discussed.

Royal jelly (RJ) was separated by ultracentrifugation (245000 X g for 5 h at 6 degreeC) into three physically distinct fractions with different distribution of its components (proteins, sugars and fatty acids): yellowish fluid supernatant (61% w/w of RJ), yellowish-brown gelatinous sediment (32% w/w) and white nearly solid sediment (7%, w/w). Ultracentrifugation of the solvated gelatinous fraction was a suitable method for preparation of MRJP1, the most abundant protein of RJ in the form of gel. MRJP1 was present in RJ in different forms: a monomer (55 kDa), oligomeric subunit (ca. 420 kDa), and water-insoluble aggregates in sediment after its interaction with fatty acids. The oligomeric MRJP1 was well soluble in water and at concentrations of 30 to 50% (w/w) formed a stiff gel. It is suggested that MRJP1 is albumin-like protein. An interesting feature of the oligomeric form of MRJP1 is its ability for self-assembly in water solutions.

Grooming behavior is considered a varroosis tolerance factor of Africanized honey bees, but this behavior is difficult to evaluate directly within the honey bee colony. A laboratory bioassay was developed to measure the intensity and effectiveness of grooming responses by worker bees artificially infested with one Varroa mite. At a study site in tropical Brazil, the sequence of seven well-defined grooming reactions towards mites of different colonial origin was compared. In a total of 226 assays, Africanized bees responded significantly faster and more intensively than Carniolan workers. But there were no statistical differences in the removal of mites according to the bee types. Even extensive grooming behavior never resulted in damage or death of the mites. The possible use of the bioassay as a screening for the extent of the grooming behavior is discussed.

Recent studies of olfactory blocking have revealed that binary odorant mixtures are not always processed as though they give rise to mixture -unique configural properties. When animals are conditioned to one odorant (A) and then conditioned to a mixture of that odorant with a second (X), the ability to learn or express the association of X with reinforcement appears to be reduced relative to animals that were not preconditioned to A. A recent model of odor-based response patterns in the insect antennal lobe predicts that the strength of the blocking effect will be related to the perceptual similarity between the two odorants, i.e. greater similarity should increase the blocking effect. Here, we test that model in the honeybee Apis mellifera by first establishing a generalization matrix for three odorants and then testing for blocking between all possible combinations of them. We confirm earlier findings demonstrating the occurrence of the blocking effect in olfactory learning of compound stimuli. We show that the occurrence and the strength of the blocking effect depend on the odorants used in the experiment. In addition, we find very good agreement between our results and the model, and less agreement between our results and an alternative model recently proposed to explain the effect.

Photoreceptor noise sets an absolute limit for the accuracy of colour discrimination. We compared colour thresholds in the honeybee (Apis mellifera) with this limit. Bees were trained to discriminate an achromatic stimulus from monochromatic lights of various wavelengths as a function of their intensity. Signal-to-noise ratios were measured by intracellular recordings in the three spectral types of photoreceptor cells. To model thresholds we assumed that discrimination was mediated by opponent mechanisms whose performance was limited by receptor noise. Most of the behavioural thresholds were close to those predicted from receptor signal-to-noise ratios, suggesting that colour discrimination in honeybees is affected by photoreceptor noise. Some of the thresholds were lower than this theoretical limit, which indicates summation of photoreceptor cell signals.

The present study deals with the aspects of phenology, floral biology and reproductive system of Jacquemontia multiflora, a caatinga species at the Fazenda Catalunha, Santa Maria da Boa Vista - PE. The species is an annual liana, with cornucopia pattern of flowering. The peak of flowering occurs between the end of March beginning of April at the end of the wet season. Its cymose inflorescences have the main axes elongated, exposing the flowers well out the foliage leaves. The blue flowers are shallow campanulate, scentless and producing a very low quantity of nectar. Anthesis is diurnal, the flowers begin to open at around 5:30 h, are ephemeral, lasting for about nine hours. The most frequent visitors are bees (Apidae and Halictidae). Apis mellifera and Trigona spinipes were considered the main pollinators of this species. J. multifora is facultatively autogamous, producing fruits either after self (30%) and cross (60%) manual pollination.

Honey-bee (Apis mellifera) colonies exhibit extreme reproductive division of labour. Workers almost always have inactive ovaries and the queen monopolises egg laying. Although extremely rare, 'anarchistic' colonies exist in which workers produce male offspring despite the presence of the queen. By comparing the rates of ovary activation in anarchistic and wild -type bees fostered to host colonies of different genotype (i.e. anarchist and non-anarchist) and queen status (i.e. queenless and queenright), we investigated the factors involved in inhibiting ovary activation. Fostered anarchist workers always had a higher level of ovary development than fostered wild-type bees in both anarchist and non-anarchist host colonies. Fostered workers of both genotypes had more active ovaries in anarchistic than in wild-type hosts. Fostered workers of both strains also had more active ovaries in queenless than in queenright hosts. The results suggest that selection for worker reproduction in the anarchistic line has both reduced the effects of brood and queen pheromones on worker ovary inhibition and increased the likelihood that workers of the anarchistic line will develop ovaries compared to wild-type workers.

Although ferromagnetic material has been detected in Apis mellifera abdomens and identified as suitable for magnetic reception, physical and magnetic properties of these particles are still lacking. Electron paramagnetic resonance is used to study different magnetic materials in these abdomens. At least four iron structures are identified: isolated Fe3+ ions, amorphous FeOOH, isolated magnetite nanoparticles of about 3 X 102 nm3 and 103 nm3 volumes, depending on the hydration degree of the sample, and aggregates of these particles. A low-temperature transition (52-91 K) was observed and the temperature dependence of the magnetic anisotropy constant of those particles was determined. These results imply that biomineralized magnetites are distinct from inorganic particles and the parameters presented are relevant for the refinement of magnetoreception models in honeybees.

Abundance and diurnal rhythms of various insect visitors on 'A' and 'R' lines were studied in hybrid seed production field of sunflower (Helianthus annuus L.) for two years at Hisar, India. Insects belonging to 41 genera of 23 families from six orders visited the capitula of 'A' and 'R' lines. Honey bees (Apis melliferra, A. dorsata and A. florea) constituted 42.2% of the total insects visiting the capitula. Abundance of natural populations of Magachile cephalotes and Xylocopa fenestrata were relatively low. Honey bees tends to visit 'R' than 'A' lines more frequently. The bee activity was highest at 06h00 and 18h00 followed by 10h00. Possible factors for rhythms in bee populations and augmentation of natural weak pollinators to obtain higher seed set have been discussed.

Field observations, floral dissections, and pollen load analyses of insects captured on 20 species of Ixia (Iridaceae), representing examples of the four major floral types in the genus, indicate that this southern African genus of 52 species is cross pollinated by a wide variety of insects. The pollination ecology of Ixia species can be divided into several distinct systems exploiting insects of four insect orders (Coleoptera, Diptera, Hymenoptera, and Lepidoptera). Ixia atrandra, I. curta, I. lutea, I. maculata, I. metelerkampiae, and I. versicolor have salver-shaped, nectarless flowers, in bright colors contrasting with dark "beetle marks" and are pollinated exclusively by hopliine scarab beetles. Four Ixia species with narrowly tubular flowers, spreading tepals, and ample nectar are pollinated by long-proboscid flies (Moegistorhynchus longirostris and Philoliche species). Three additional species with tubular flowers, and modest nectar volumes, appear to be pollinated by the pieriid butterfly, Colias electo (Ixia orientalis), or by a combination of hopliine beetles and tabanid flies with short probosces (I. aurea, I. esterhuyseniae, I. tenuifolia). The remaining species are largely pollinated by anthophorine bees or Apis mellifera, but bee pollination comprises three discrete systems. Species pollinated by Anthophora and Pachymelus species (I. capillaris, I. latifolia, I. odorata, I. rapunculoides, I. thomasiae) have cup-shaped flowers that secrete nectar. Salver-shaped flowers of I. flexuosa secrete no nectar, but are pollinated by pollen-collecting Apis mellifera. Buzz pollination by Amegilla fallax in I. scillaris is associated with vertical floral presentation, nectarless flowers, unusual in having a short, closed perianth tube, short, stubby filaments, and anthers dehiscing incompletely from the base. Outgroup comparison suggests that the ancestral pollination system in Ixia is the one in which flowers are cup-shaped, produce nectar, and are pollinated by large anthophorine bees. Exaggeration of the perianth into an elongate tube containing ample nectar, or the closure of the perianth tube and absence of nectar, or the development of basal anther dehiscense must be regarded as specialized adaptations related to their derived pollination strategies.

Fire in Mediterranean-type ecosystems produces catastrophic changes in plant-pollinator systems; the recovery of which has been studied by comparing an unburnt mature forest habitat with that of an adjacent recently burnt area (eight years post-fire). The composition, visitation profiles, and effectiveness of the taxonomically diverse pollinator assemblages found on a core nectar providing species (Satureja thymbra: Lamiaceae) were examined in these two contrasting habitats. S. thymbra in the freshly burnt area had low nectar standing crop and relatively less diverse bee community than an unburnt area which had twice the nectar standing crop and a higher bee diversity and abundance. Both sites supported bee assemblages dominated by the non-native bumblebee Bombus terrestris. Spatio-temporal heterogeneity of nectar standing crops and microclimatic conditions were sufficient to explain the form and magnitude of the diurnal foraging profiles at each site in relation to species specific foraging and flight abilities. B. terrestris, Apis mellifera and native solitary bees were the three primary guilds visiting S. thymbra and varied in the efficiency with which they delivered conspecific pollen grains to receptive stigmas. A pollinator effectiveness index for these three guilds was calculated based on floral visitation rates and pollen delivery efficiency and reflected the actual levels of effectiveness of each guild within and across the two habitat types. There was no overall inter-community difference in pollination effectiveness as the bee assemblages in both habitats were sufficient to produce maximum fruit set in S. thymbra, though the relative contribution of each guild varied intra -communally. Pollen limitation was not found to occur in either habitat.

Honey samples of one apiary located in Contao village, north of Roraima State, Brazil were analyzed. The samples originated from crops of October and December, 1996 and January, February and March, 1997. A total of 20 pollen types were identified; they were distributed among 18 genera and 13 families. The families: Mimosaceae (4 species), Anacardiaceae (3 species), Sterculiaceae (2 species), Caesalpiniaceae (2 species) and Amaranthaceae (2 species) were the most represented. The other families were represented by a single species. The most frequent pollen types were: Mimosa polydactyla (October and December, 1996) and Curatella americana (January,February and March, 1997).Three significant correlations among the frequencies of pollen types were found; Curatella americana L. X Mimosa polydactyla G.B.K. (r = -0,99), Curatella americana L. X Astronium sp (r = 0,95) e Mimosa polydactyla H.B.K e Astronium sp (r = -0,91).

In insects, the transport of airborne, hydrophobic odorants and pheromones through the sensillum lymph is generally thought to be accomplished by odorant-binding proteins (OBPs). We report the structural and functional properties of a honeybee OBP called ASP2, heterologously expressed by the yeast Pichia pastoris. ASP2 disulfide bonds were assigned after classic trypsinolysis followed by ion-spray mass spectrometry combined with microsequencing. The pairing (Cys(I)-Cys(III), Cys(II)-Cys(V), Cys(IV) -Cys(VI)) was found to be identical to that of Bombyx mori OBP, suggesting that this pattern occurs commonly throughout the highly divergent insect OBPs. CD measurements revealed that ASP2 is mainly constituted of alpha helices, like other insect OBPs, but different from lipocalin-like vertebrate OBPs. Gel filtration analysis showed that ASP2 is homodimeric at neutral pH, but monomerizes upon acidification or addition of a chaotropic agent. A general volatile-odorant binding assay allowed us to examine the uptake of some odorants and pheromones by ASP2. Recombinant ASP2 bound all tested molecules, except beta-ionone, which could not interact with it at all. The affinity constants of ASP2 for these ligands, determined at neutral pH by isothermal titration calorimetry, are in the micromolar range, as observed for vertebrate OBP. These results suggest that odorants occupy three binding sites per dimer, probably one in the core of each monomer and another whose location and biological role are questionable. At acidic pH, no binding was observed, in correlation with monomerization and a local conformational change supported by CD experiments.

Foraging behavior and the mechanisms that regulate foraging activity are important components of social organization. Here we test the hypothesis that brood pheromone modulates the sucrose response threshold of bees. Recently the honeybee proboscis extension response to sucrose has been identified as a "window" into a bee's perception of sugar. The sucrose response threshold measured in the first week of adult life, prior to foraging age, predicts forage choice. Bees with low response thresholds are more likely to be pollen foragers and bees with high response thresholds are more likely to forage for nectar. There is an associated genetic component to sucrose response thresholds and forage choice such that bees selected to hoard high quantities of pollen have low response thresholds and bees selected to hoard low quantities of pollen have higher response thresholds. The number of larvae in colonies affects the number of bees foraging for pollen. Hexane-extractable compounds from the surface of larvae (brood pheromone) significantly increase the number of pollen foragers. We tested the hypothesis that brood pheromone decreases the sucrose response threshold of bees, to suggest a pheromone-modulated sensory-physiological mechanism for regulating foraging division of labor. Brood pheromone significantly decreased response thresholds as measured in the proboscis extension response assay, a response associated with pollen foraging. A synthetic blend of honeybee brood pheromone stimulated and released pollen foraging in foraging bioassays. Synthetic brood pheromone had dose-dependent effects on the modulation of sucrose response thresholds. We discuss how brood pheromone may act as a releaser of pollen foraging in older bees and a primer pheromone on the development of response thresholds and foraging ontogeny of young bees.

Recent Ca2+-imaging studies on the antennal lobe of the honeybee (Apis mellifera) have shown that olfactory stimuli evoke complex spatiotemporal changes of the intracellular Ca2+ concentration, in which stimulus -dependent subsets of glomeruli are highlighted. In this work we use nonlinear models for the quantitative identification of the spatial and temporal properties of the Ca2+-dependent fluorescence signal. This technique describes time series of the Ca2+ signal as a superposition of biophysically motivated model functions for photobleaching and Ca2+ dynamics and provides optimal estimates of their amplitudes (signal strengths) and time constants together with error measures. Using this method, we can reliably identify two different stimulus-dependent signal components. Their delays and rise times, deltac1 = (0.4 +- 0.3) s, tauc1 = (3.8 +- 1.2) s for the fast component and deltac2 = (2.4 +- 0.6) s, tauc2 = (10.3 +- 3.2) s for the slow component, are constant over space and across different odors and animals. In chronological experiments, the amplitude of the fast (slow) component often decreases (increases) with time. The pattern of the Ca2+ dynamics in space and time can be reliably described as a superposition of only two spatiotemporally separable patterns based on the fast and slow components. However, the distributions of both components over space turn out to differ from each other, and more work has to be done in order to specify their relationship with neuronal activity.

We demonstrate the effects of a new quantitative trait locus (QTL), designated pln3, that was mapped in a backcross population derived from strains of bees selected for the amount of pollen they store in combs. We independently confirmed pln3 by demonstrating its effects on individual foraging behavior, as we did previously for QTLs pln1 and pln2 (Hunt et al. 1995). QTL pln2 is very robust in its effects on foraging behavior. In this study, pln2 was again shown to affect individual foraging behavior of workers derived from a hybrid backcross of the selected strains. In addition, pln2 was shown to affect the amount of pollen stored in combs of colonies derived from a wide cross of European and Africanized honeybees. This is noteworthy because it demonstrates that we can map QTLs for behavior in interstrain crosses derived from selective breeding and study their effects in unselected, natural populations. The results we present also demonstrate the repeatability of finding QTLs with measurable effects, even after outcrossing selected strains, suggesting that there is a relatively small subset of QTLs with major effects segregating in the population from which we selected our founding breeding populations. The different QTLs, pln1, pln2, and pln3, appear to have different effects, revealing the complex genetic architecture of honeybee foraging behavior.

For the vast majority of higher plants, animal-mediated pollination is essential for reproduction by seed. Yet, plants and their pollinators currently face a variety of threats including habitat fragmentation, invasive species, and poisoning by pesticides. As land is increasingly converted to human uses, the diversity and abundance of plants and pollinators is likely to decline. Plants with small or low-density populations, including many rare species, can receive fewer pollinator visits, which could lead to fewer seeds, higher selfing rates, and more inbreeding depression. Recent research indicates that introduced honeybees (Apis mellifera L.) can competitively displace native pollinators, and because honeybees are often poor pollinators compared to native bees, the reproductive success of native plants might decline. Application of chemical pesticides can have adverse effects on pollinator populations and reduce natural pollination and subsequent seed set in wild plants. Insecticide-free buffer zones might be needed around some rare plant populations. Plant species that are most vulnerable to pollinator loss are those that depend on a single pollinator species. Many species reduce their risk of pollinator loss via compensatory mechanisms such as multiple pollinators, self-pollination, or by decreasing their dependence on seeds via vegetative reproduction or long life spans. These traits, however, are unlikely to compensate in the long term for a continuous decline in pollination services. Key to slowing the rate of species loss and keeping natural pollination systems intact is habitat preservation. For rare species that depend on pollinators, conservation managers may need to consider factors that influence the welfare of pollinators. Moreover, the size of preserves is important because pollinator nest sites, larval food plants, and foraging sites may be spatially separated and occupy different habitats. Given that pollination interactions often involve multiple species assemblages and large landscapes, a community or ecosystem-based management perspective is needed.

The control of the pupal melanization in the honey bee by ecdysteroids, and the modulation of these processes by a juvenile hormone analog were investigated by a combination of in vivo and in vitro experiments. Injection of 1-5 mug of 20-hydroxyecdysone (20E) into unpigmented pupae showed a dose- and stage-dependent effect. The higher the dose and the later the injection was performed, the more pronounced was the delay in cuticle pigmentation. This inhibition of cuticular melanization by artificially elevated ecdysteroid titers was corroborated by in vitro experiments, culturing integument from unpigmented, dark-eyed pupae for 1 -4 days in the presence of 20E (2 or 5 mug/ml culture medium). Topical application (1 mug) of pyriproxyfen to unpigmented, white-eyed pupae had the opposite effect, leading to precocious and enhanced melanization of the pupal cuticle. In vitro incubation of integuments in the presence of this juvenile hormone analog (1 mug/ml) confirmed these results, showing that pyriproxyfen is apparently capable of triggering melanization. The in vivo mode of action of pyriproxyfen was further investigated by quantifying hemolymph ecdysteroids by radioimmunoassays. Topical application leads to a delay of the pupal ecdysteroid peak by 4 days. The pyriproxyfen-induced low ecdysteroid titers during early pupal development could account for precocious pigmentation by removing an inhibition on prophenoloxidase activation normally imposed by the elevated ecdysteroid titer during this phase.

Risk-sensitivity was studied in free-flying honeybees trained individually to choose between two scented targets (A and B) with varying amounts and concentrations of sucrose solution as reward. In the first phase of experiment 1, the animals showed 'risk-aversion,' preferring A, which provided 5 mul of a 40% sucrose solution on every trial, to B, which provided 30 mul of the same solution once in every six trials (mean amount per trial 5 mul for each alternative). In the second phase, the preference reversed with reversal of the reward assignments. In experiment 2, the consistently rewarded A (5 mul of 40% sucrose solution per trial) was again preferred, although the inconsistently rewarded B now provided twice the amount of sucrose solution on average (30 mul on two of every six trials, mean amount per trial 10 mul). In experiment 3, with A providing 10 mul of a 15% sucrose solution on every trial and B providing 10 mul of a 60% sucrose solution on two of every four trials (mean concentration per trial 30%), the animals preferred B. In experiment 4, patterned after experiment 1, similar results were obtained under more natural conditions in which the animals were no longer constrained (as they were in the first three experiments) to go equally often to each alternative. The results of all four experiments were predicted quantitatively and with considerable accuracy by a simple associative theory of discriminative learning in honeybees.

An ectoparasitic mite Tropilaelaps clareae infesting Apis dorsata in Asia has quickly moved onto a new host Apis mellifera in the middle of the twentieth century and became a problem for beekeepers in Asia and South Africa. The mite needs to be on the brood almost constantly. Mite infestation is more severe during active brood rearing periods. On hatching, the nymph feeds on the haemolymph of capped larvae and pupae, and adult mites finally emerge out from the infested cells. Adult bees do not emerge or the affected brood develops into deformed adults. Inspection of hives severely infested by the mite reveals an irregular pattern of sealed and unsealed brood. Since adults of T. clareae can survive without bee brood as food for only 2 days, restricting of brood production combined with chemical treatment can control the mite pest. Bees and queens should be subject to inspection by veterinary service at the time of importation for the purpose of determining whether they are eligible to be imported to places free of T. clareae. Veterinarians and beekeepers should constantly monitor the hives for the presence of exotic mites to prevent a threat to the health and welfare of bees.

Pollen spectrum found in honey samples from six localities of Bahia State, Brazil, was analyzed with the objective to contribute for the knowledge of the plants used by Apis mellifera L., 1758 (Hymenoptera: Apidae). The identification of the pollen types was made by specialized literature and by field information. Two hundred pollen grains were studied in order to determine the percentage and the occurrence of each type. Forty three pollen types were identified, being considered as the predominant types Eucalyptus sp. (Myrtaceae), Mimosa verrucosa Benth. (Mimosaceae), M. scabrella Benth. (Mimosaceae) and Bauhinia sp. (Caesalpiniaceae). The accessory pollen types were Alternanthera ficoidea R.Br. (Amaranthaceae), Compositae type (Asteraceae) and Cecropia sp. (Moraceae). It is intense the participation of Mimosa sp. (Mimosaceae) and other wild species in the honey composition of the six localities considered. Eucalyptus sp. (Myrtaceae) is one of the dominant sources of bee food in some regions of Bahia State.

Flying insects achieve the highest known mass-specific rates of O2 consumption in the animal kingdom. Because the flight muscles account for RGT 90% of the organismal O2 uptake, accurate estimates of metabolic flux rates (J) in the muscles can be made. In steady state, these are equal to the net forward flux rates (v) at individual steps and can be compared with flux capacities (Vmax) measured in vitro. In flying honeybees, hexokinase and phosphofructokinase, both nonequilibrium reactions in glycolysis, operate at large fractions of their maximum capacities (i.e., they operate at high v/Vmax). Phosphoglucoisomerase is a reversible reaction that operates near equilibrium. Despite Vmax values more than 20 -fold greater than the net forward flux rates during flight, a close match is found between the Vmax required in vivo (estimated using the Haldane relationship) to maintain near equilibrium and this net forward flux rate and the Vmax measured in vitro under simulated physiological conditions. Rates of organismal O2 consumption and difference spectroscopy were used to estimate electron transfer rates per molecule of respiratory chain enzyme during flight. These are much higher than those estimated in mammalian muscles. Current evidence indicates that metabolic enzymes in honeybees do not display higher catalytic efficiencies than the homologous enzymes in mammals, and the high electron transfer rates do not appear to be the result of higher enzyme densities per unit cristae surface area. A number of possible mechanistic explanations for the higher rates of electron transfer are proposed.

It is generally accepted that the dronefly Eristalis tenax is a Batesian mimic of the honeybee Apis mellifera. Previous work has established that the foraging behaviour of droneflies is more similar to that of its model than to that of other more closely related flies, suggesting that behaviour may be important in the mimicry. Locomotor mimicry has been demonstrated in mimetic Heliconius butterflies but not in hoverflies. This study therefore investigated aspects of the flight behaviour of Eristalis tenax, Apis mellifera and two other flies, Syrphus ribesii and a Musca sp. Insects were filmed foraging on Helichrysum bracteum flowers, and flight sequences were analysed to determine flight velocities, flight trajectories and the percentage of time spent hovering. It was found that the flight behaviour of droneflies was more similar to that of honeybees than to that of the other flies. This suggests that the flight behaviour of Eristalis tenax may be mimetic.

Odours are received by olfactory receptors, which send their axons to the first sensory neuropils, the antennal lobes (in insects) or the olfactory bulb (in vertebrates). From here, processed olfactory information is relayed to higher-order brain centres. A striking similarity in olfactory systems across animal phyla is the presence of glomeruli in this first sensory neuropil. Various experiments have shown that odours elicit a mosaic of activated glomeruli, suggesting that odour quality is coded in an 'across-glomeruli activity code. In recent years, studies using optical recording techniques have greatly improved our understanding of the resulting 'across-glomeruli pattern', making it possible to simultaneously measure responses in several, often identifiable, glomeruli. For the honeybee Apis mellifera, a functional atlas of odour representation is being created: in this atlas, the glomeruli that are activated by different odorants are named. However, several limitations remain to be investigated. In this paper, we review what optical recording of odour -evoked glomerular activity patterns has revealed so far, and discuss the necessary next steps, with emphasis on the honeybee.

Sacbrood virus (SBV) infects larvae of the honeybee (Apis mellifera), resulting in failure to pupate and death. Until now, identification of viruses in honeybee infections has been based on traditional methods such as electron microscopy, immunodiffusion, and enzyme-linked immunosorbent assay. Culture cannot be used because no honeybee cell lines are available. These techniques are low in sensitivity and specificity. However, the complete nucleotide sequence of SBV has recently been determined, and with these data, we now report a reverse transcription-PCR (RT-PCR) test for the direct, rapid, and sensitive detection of these viruses. RT-PCR was used to target five different areas of the SBV genome using infected honeybees and larvae originating from geographically distinct regions. The RT-PCR assay proved to be a rapid, specific, and sensitive diagnostic tool for the direct detection of SBV nucleic acid in samples of infected honeybees and brood regardless of geographic origin. The amplification products were sequenced, and phylogenetic analysis suggested the existence of at least three distinct genotypes of SBV.

The most common method used to assess the level of mite infestation in a bee colony is to count all the mites that fall onto sticky boards placed on the bottom of a colony. Unfortunately, this is a laborious and boring task. Therefore, a stratified sampling technique was devised to accurately estimate the number of mites on sticky boards. The technique, when compared to a census count of all mites, resulted in a coefficient of determination of 0.97 or greater. The stratified sampling protocol in which we randomly selected 33% of the cells on a sticky board and did not choose new random numbers for each sticky board resulted in an accurate estimate of the number of Varroa jacobsoni. This technique gave a mean percent error of 0.4%+-9.5% for any one estimate of a sticky board.

Nosema apis inoculated and non-inoculated honeybee (Apis mellifera) queens were introduced into mating nuclei. The workers accepted all queens from both groups. During the 26 days of the experiment, 47.4% of the inoculated and 50% of the non-inoculated queens were lost. Queens from both groups started egg-laying after 15.8 days. Workers did not perceive the presence of N. apis in their queens and did not supersede inoculated queens significantly more often than healthy ones. Significantly more workers were infected in the mating nuclei with inoculated queens (61%) than in those with non-inoculated ones (5.3%).

This study examines changes in reproduction and mortality of Varroa destructor when queens from stocks of honey bees (Apis mellifera L.) that differ in susceptibility to the mites were exchanged between colonies. Queens were selected for suppression of mite reproduction (SMRD). In two experiments uniform colonies of bees were established; half the colonies were given queens selected for SMRD, and half were given unselected queens. Queens were exchanged after 7 (experiment 1) and 13 weeks (experiment 2). The percentage of mites that had no progeny was determined for each colony at 5 times (2 before and 3 after exchanging queens). Mites that had no progeny included live and dead mites. Results showed (1) that reproduction of mites is suppressed by adding a queen selected for SMRD, and (2) that a mite population recovers its reproduction when a SMRD queen is replaced by an unselected queen. Selection of the SMRD trait can be reduced to counting only live mites that laid no eggs and dead mites.

Two thousand specimens of Apis mellifera L. from three domesticated populations in Bulgaria were investigated by means of polyacrylamide gel electrophoresis (PAGE), starch gel electrophoresis (SGE) and isoelectric focusing in ultra-thin poyacrylamide gel. Specimens of different developmental stages and sexes were compared: unsealed and sealed larvae, white-eyed and dark-eyed pupae, and imago forms (7-day worker bees, 10-day drones, and one-day queen). All samples were total extracts of individuals, except the egg samples which were made up of 20 eggs. PAGE was performed according to Maurer. SGE was performed according to Smithies as modified by Dobrovolov. The soluble proteins were visualised with Commassie Brilliant Blue R250. A total of 24 fractions of water-soluble proteins were found in the spectra of analyzed organs in PAGE: 10 in eggs, 17 in unsealed larvae, 18 in sealed larvae, 14 in pupae, 18 in workers and drones and 19 in queens (Tab. I, Fig. 1). In SGE 20 fractions were found: 8 in unsealed larvae, 11 in sealed larvae, 10 in pupae, 9 in workers, 11 in drones and 12 in queens (Tab. II, Fig. 2). With isoelectric focusing 31 fractions were found in eggs, 50 in unsealed and sealed larvae, 48 in pupae, 52 in workers and 48 in drones (Fig. 3). After separation in starch gel we found 2 queen specific and 2 drone specific bands. With PAGE, more bands were obtained but only one sex specific band (M) could be found. The best separation with up to 52 fractions was obtained by isoelectric focusing. There was 1 band at the anode and 2 bands at the cathode which occurred only in drones. With both SGE and PAGE we found protein bands which occurred during the larval and pupal but not in the adult stages (SQ and SH - F, L, W and Y respectively) which may point to specific larval proteins.

Using polyacrylamide gel electrophoresis (PAGE), 368 organ extracts of drones were investigated. The soluble proteins spectra were analyzed in separate organs from the different specimens at various ontogenetic stages (unsealed larvae, sealed larvae, white-eyed pupae, dark-eyed pupae and imago forms). The organs tested (heart, gut, testicle, mucus glands and eyes) were isolated by dissection, rinsed with distilled water, squashed in 0.1 M tris-phosphate buffer at pH 6.7, and left for extraction for 24 h at 4 degreeC. Then the samples were centrifuged for 30 min at 900 g. For electrophoretic separation, a 7.5% polyacrylamide vertical gel (pH 8.9) was used, together with 3.3% concentrating gel at pH 6.7 and 0.05 M tris - 0.2 M glycine electrode buffer, at pH 8.3. The soluble proteins were visualised with Commassie Brilliant Blue R 250. A total of 31 fractions of water-soluble proteins were found in the spectra of analyzed organs - 22 in heart extract, 24 in extract of gut, 21 in extracts of testes, 20 - in extracts of mucus glands and 16 - in eye extracts (Tab. I). An organ and stage specificity in the appearance of soluble proteins during development of Apis mellifera drones could be shown. Organ specific bands were found in the reproductive organs: testis ((A and G) and mucus glands (A), as well as in the intestine (K, L and ZC) and the heart (ZA + ZE) (Figs. 1 and 2).

The role of the worker honey bee Apis mellifera L. changes depending on age after eclosion (age polyethism): young workers (nurse bees) take care of their brood by synthesizing and secreting brood food (royal jelly), while older workers (foragers) forage for nectar and process it into honey. Previously, we showed that the major proteins synthesized in the hypopharyngeal gland of the worker change from brood food proteins to alpha-glucosidase at the single secretory cell level in parallel with this age polyethism (Kubo et al., J. Biochem. 119, 291-295 (1996); Ohashi et al., Eur. J. Biochem. 249, 797-802 (1997)). Here, we examined whether the function of the hypopharyngeal gland has flexibility depending on the colony conditions, by creating a dequeened colony in which the older workers were compelled to feed the drone larvae. It was found that most of the older workers in the dequeened colony synthesized brood food proteins as did nurse bees. Furthermore, the percentage of workers that synthesized brood food proteins was maintained at 80-90% of the total workers for at least two months, as in a normal colony. These results indicate that the function of the hypopharyngeal gland cells of the worker has flexibility and can, if necessary, be maintained as that of the nurse bee, depending on the condition of the colony.

We tested compounds found in honey bee, Apis mellifera L., sting alarm pheromone for their roles in releasing behavioral responses, with a focus on the relative importance of chemotaxis and motion of the target in the localization response. Some compounds in the blend have specialized functions. Benzyl acetate released only flight behavior, whereas three compounds (1-butanol, 1-octanol, and hexyl acetate) caused only the recruitment response. Other compounds (1-hexanol, butyl acetate, iso -pentyl acetate, and 2-nonanol) acted in more than one behavioral context. Octyl acetate was the most effective compound in allowing bees to locate targets, but did not recruit or release flight behavior. Stationary octyl acetate sources were located by flying bees, indicating that this pheromone component elicits a chemotactic response. However, localization of a target is due primarily to the motion of the target; the alarm pheromone components release searching behavior for a moving object and are relatively unimportant in target localization.

Our primary objective was to identify techniques to transform the genome of the honey bee (Apis mellifera) with foreign DNA constructs. The strategy we adopted was to linearize foreign DNA and introduce it with sperm during the instrumental insemination of virgin queen honey bees. We analysed extracts from larvae within the same cohort and isolated the predicted fragment by means of PCR amplification of genomic DNA. Larvae that carried the construct also expressed the introduced DNA. We propagated several transgenic lines for up to three generations, which demonstrates its heritability. Once carried by a queen, the construct can be detected in that queen's larvae over several months. However, there was no evidence of integration of the construct, at least as determined by genomic Southern analysis. Nevertheless, this demonstrates the general viability of the technique for introduction of DNA, and it should be augmented by further use of transposable elements that enhance integration.

We describe four members of the tetraspanin/TM4SF superfamily of proteins that were identified in expressed sequence tag projects on the antennae of Manduca sexta moths and Apis mellifera honey bees. The three moth genes are expressed in the sensillar epithelium of male antennae, and some are expressed in female antennae, haemocytes, wing scale cell primordia and/or embryonic tissues. These proteins are probably involved in diverse cellular processes, much like their vertebrate homologues. A phylogenetic analysis of all known tetraspanins, including thirty-seven members of the superfamily revealed by the Drosophila melanogaster genome and twenty in the nematode Caenorhabditis elegans genome, reveals some phylum-specific gene amplification, in particular a contiguous array of eighteen genes in the D. melanogaster genome.

Most studies of discrimination in the context of queen rearing have been performed in spring or summer, but the influence of environmental conditions on nepotism in honeybees has not received attention. Our experiments were designed to test the hypothesis that restricted resources influence honeybee workers to express a bias towards rearing related larvae more strongly than under favorable conditions. Three experimental designs were employed. In the first experiment, larvae were grafted using standard commercial techniques for rearing queens. Nurse bees were presented with sister larvae and alien larvae placed each in a cup, side by side in alternating positions. In the second experiment, nurse bees were offered the choice between sister or alien larvae placed in the same cup. The third experiment was similar to the first except that the objective was to harvest and weigh the accepted larvae and the remaining royal jelly. This study demonstrates that our colonies did not display nepotism in the context of queen rearing, whatever the season.

The flow of incoming nectar in honeybee (Apis mellifera L.) colonies was simulated by feeding a sucrose solution labeled with a novel protein (rabbit IgG) marker and then analyzing bee and colony samples using an enzyme-linked immunosorbant assay (ELISA). The labeled sucrose solution was quickly transported to food storage and brood combs. Within 2h, equal percentages of worker bees from food storage combs, nurse bees and nectar samples tested positive for the marker. Percentages of nurse bees and larvae testing positive also were equal within the first 2 h of feeding it to a colony and these percentages increased over time. Our results suggest that workers with nectar loads deposit them into cells on either food storage or brood comb with equal frequency. The labeled sucrose solution transported to the brood comb is subsequently used by nurse bees to feed larvae. How the deposition of incoming nectar in brood comb might possibly integrate the activities of foragers and nurse bees is discussed.

This study was conducted to record the honey production of honey bee colonies (Apis mellifera L.) infested with the mite Varroa jacobsoni Oud., and that of colonies treated with fluvalinate. An apiary with 91 colonies was established. Each colony received a new, young, and mated queen. Queens were obtained from seven different queen breeding operations throughout Mexico. Colonies were infested with an equal number of mites, and were managed in a similar way until their honey crop was harvested. A group of 33 colonies was treated with the miticide fluvalinate (Apistan(R)), whereas the control group of 58 colonies did not receive any treatment against the mite. Honey yield and level of infestation of each of the colonies were measured at the end of the blossom season. Colonies of the treated group produced significantly more honey (65.5%), and were significantly less infested than the colonies of the untreated group (t = 3.32; gl = 89; p LGT 0.01 for honey production; t = 6.33; gl = 89; p LGT 0.01, for infestation levels). Results suggest that colonies infested with Varroa jacobsoni should be treated with miticides, meanwhile other control methods are developed. This is the first study which suggests that Varroa jacobsoni damages honey production in Mexico.

In 1956, honey bees of the African subspecies A. m. scutellata were imported to Brazil, and their descendents subsequently spread to South, Central, and North America. This invasion sparked significant academic controversy, particularly concerning the genetic composition of the expanding population. We review the biogeography and intraspecific phylogeny of Apis mellifera in the Old World as it pertains to African -derived bees in the Americas, the methods used to study gene flow between European-derived and African-derived populations in the New World, and the techniques used in identification of African-derived bees.

The foraging force and pollen collection of European and European X Africanized hybrid worker honey bees, Apis mellifera L., housed in a common nest environment were compared. Significant heterogeneity was found within both genotype populations for the proportion of the bees that foraged, as well as for the proportion of foragers that collected pollen. However, there was not a consistent bias for either genotype to collect pollen or to field a greater proportion of the total foraging population. These results suggest that when sharing a common environment, European X Africanized hybrids and European honey bees do not differ with respect to individual foraging decisions. Results also suggest that the pollinating efficiency of commercial colonies maintained in Africanized areas will probably not diminish as a consequence of introgression of African honey bee genes, if problems associated with their management can be controlled.

A polymerase chain reaction (PCR)-based restriction fragment-length polymorphism (RFLP) assay was developed that discriminates among the 4 mitotypes found in North, Central, and South American honey bee racial groups-eastern European (Apis mellifera ligustica Spinola, caucasica Gorbachev, and carnica Pollman), western European (A. m. mellifera Linnaeus), Egyptian (A. m. lamarckii Cockerell Lepeletier), and sub -Saharan African (A. m. scutellata). Before the development of this assay, 13% of southern Californian feral bees collected before the arrival of the Apis mellifera scutellata (Africanized) race were found to contain a non -European mitochondrial genotype that could not be distinguished from that of A. m. scutellata. DNA sequence analysis suggests the unusual mitotype to be that of A. m. lamarckii. An RFLP polymorphism was identified that distinguished this subspecies from all others present in North America. This polymorphism was not found in any of 96 bees collected primarily in Mexico and Central America. Thus, the Egyptian mitochondrial type is either absent or extremely rare in these regions. The PCR assay also distinguishes A. m. lamarckii from 2 other north African racial types, A. m. intermissa Buttel-Reepen and A. m. sahariensis Baldensperger.

The foraging activity of pollinator insects in relation to weather factors (ambient temperature, solar radiation, relative humidity, and wind speed) was studied in an apple orchard with special reference to two managed bee species, Osmia cornuta (Latreille) and Apis mellifera L. Over the range of observed weather values, A. mellifera activity was significantly dependent on temperature, solar radiation, and wind speed; O. cornuta activity was dependent on solar radiation and wind speed. These results were confirmed through video recordings at one O. cornuta nesting shelter and one A. mellifera hive. For both species, daily activity started at lower temperatures than it ceased, whereas solar radiation did not differ between these two events. In general, O. cornuta was active from 10 to 12degreeC and 200 w/m2, and A. mellifera from 12 to 14degreeC and 300 w/m2. O. cornuta was the only bee species seen visiting apple flowers under strong wind or light rain. Because of its greater tolerance to inclement weather, O. cornuta pollinated apple flowers for longer periods (both daily and seasonally) than other flower visitors.

The foraging behavior and pollinating efficacy of Osmia cornuta (Latreille) and Apis mellifera L. were studied in an orchard of 'Delicious' apple, Malus domestica Borkh, in northeastern Spain. Yields after one single visit were more than five times higher in flowers visited by O. cornuta than in those visited by A. mellifera nectar gatherers. This is attributed to the lower rate of stigma contact in A. mellifera visits, rather than to insufficient deposition of compatible pollen when the stigmas are contacted. A. mellifera pollen collectors had very high rates of stigma contact, but they were very scarce (3%) on 'Delicious' flowers despite the presence of abundant brood in their hives. One single visit per flower by O. cornuta produced commercial fruit set (27.4%) and fruit size ( RGT 70 mm diameter). Based on cell production, average number of trips required to provision a male and a female cell, and flower visiting rates, it is estimated that a mean of 22,252 apple flower visits per female O. cornuta were made during the 15-d flowering period. This result indicates that 530 nesting O. cornuta females per hectare are enough to provide adequate apple pollination.

The vertical distribution of insect orders, families, and species captured over 10 elevations from the ground to 15 m over 4 years in a potato agro -ecosystem differed considerably within and between taxa. Regression slopes representing these aerial profiles remained similar over the 4 years of the study for orders Thysanoptera, Neuroptera, and Psocoptera, changed considerably for Hemiptera, Homoptera and Ephemeroptera, and were statistically non-homogeneous for Coleoptera, Hymenoptera, Diptera, Lepidoptera, Trichoptera, and Plecoptera. The slopes of the aerial profiles for families remained similar over the years for Carabidae and Elateridae, changed for Staphylinidae, Meloidae, and Scarabeidae, but were statistically non-homogeneous for Coccinellidae, Miridae, and Aphididae. The slopes of the aerial profiles for insect species were similar across years for Coccinella septempunctata L., Melanotus similis (Kirby), and Anatis mali Say, changed for Pyrrhalta luteola (Mull.), Ctenicera pulchra LeConte, Ctenicera tarsalis Melsheimer, Coccinella trifasciata perplexa Muls., Lygus lineolaris (P. de B.), Ctenicera appropinquans Randall, Apis mellifera L., and Adalia bipunctata (L.), but were significantly non -homogeneous only for Hippodamia convergens G.-M. Although most profiles obtained for insect orders in this study were remarkably similar to those reported in the literature, the level of between-year variation at our study site suggests that there is considerable overlap between profiles at all taxon levels. Vertical aerial profiles cannot be considered sufficiently characteristic of the species, family, or order across years for use as indicators of change in biodiversity. The impact of these results on insect monitoring are discussed.

In honey bee (Apis mellifera) colonies, scouts search for productive forage sites and then recruit other workers to those locations using a waggle dance. A simple and tractable mathematical model of the honey bee scout -recruit system was developed to study the relationship between nectar availability, the efficiency of the honey bee's recruitment system, and the optimal proportion of scouts that maximizes net gain (benefit - cost), or, energetic efficiency (benefit/cost - 1). The models consider both the energetic costs and benefits of active scouts and recruits as well as the cost of an inactive forager reserve. They predict conditions when individual foraging is favored over the honey bee's recruitment system, when the colony should abandon foraging altogether, and the optimal proportion of scouts (when the scout-recruit system is favored). The models' predictions qualitatively match empirical data. Surprisingly, previous empirical data from the honey bee suggest that recruits' costs are greater than scouts'-recruits spend significantly longer searching for a forage patch than do scouts-thereby causing researchers to rethink how the scout-recruit system might be adaptive. Using average returns, the models demonstrate how the scout-recruit system is adaptive despite these apparent higher recruit costs relative to the scouts'. A sensitivity analysis demonstrates that the results are robust to a broad range of relative costs of active workers, inactive workers, and the energetic benefits of the forage. Consequently, the model is demonstrated to be relevant to many insect societies that employ a scout-recruit system.

Honeybee (Apis mellifera) colonies rob honey from each other during periods of nectar shortage. Persistent robbing can kill weak colonies. Primarily responsible for preventing robbing are guard bees. Previous research has shown that the probability of both nest mate and non-nest mate workers being accepted by guards at the nest entrance increases as nectar availability increases. The mechanism responsible for this change in guard acceptance can be explained by two competing hypotheses: Odor Convergence and Adaptive Threshold Shift. In this study we tested the Odor Convergence hypothesis. The acceptance by guards at the nest entrance of workers transferred between four colonies that had been fed either odorless sucrose syrup (two colonies) or diluted heather honey (Calluna vulgaris) (two colonies) was measured for 3 days before feeding and during 2 weeks of feeding. Despite the large sample sizes, the probability of guards accepting non-nest mates was not affected by the similarities or dissimilarities in food odor between guards' and non-nest mates' colonies. This finding contrasts with the accepted wisdom that food odors are important in nest mate recognition in honeybees and the data, therefore, strongly reject the Odor Convergence hypothesis.

Mutillid wasps influence humans only slightly because they rarely occur in large numbers. Many species, however, are conspicuous because of their bright aposematic coloration. In some geographical regions, members of this family are well known for the painful stings of the females. There are many different common names for some species of Mutillidae, and they sometimes feature in myths and in naturopathy. In applied entomology they play a role only in two cases: (a) In the first half of the 20th century, Mutilla europaea Linnaeus 1758 was reported to cause damage in colonies of honeybees. (b) Some species of Mutillidae have been reported to be parasitoids of tsetse flies (Glossina spp).

Twenty-one propolis samples produced by 12 different Meliponinae species were analyzed by GC-MS. Several chemical types of stingless bees' propolis could be grouped, according to the prevailing type of compounds like: "gallic acid", "diterpenic" and "triterpenic" types. The results confirm that neither the bee species nor the geographical location determine the chemical composition of Meliponinae propolis and the choice of its plant source, respectively. This could be explained by the fact that Meliponinae forage over short distances (maximum 500 m) and thus use as propolis source the first plant exudate they encounter during their flights. The antibacterial, antifungal and cytotoxic activities of the samples were also investigated. Most samples had weak or no activity against E. coli, weak action against Candida albicans. Some of them showed significant activity against St. aureus., presumably connected to the high concentration of diterpenic acids. Samples rich in diterpenic acids possessed also high cytotoxic activity (Artemia salina test).

Background: Double sensitization to honeybee (Apis mellifera) and wasp venom (Vespula spp.) as determined by skin test and measurement of specific IgE is common in hymenoptera sting allergy. Double-sensitized patients have either distinct antibodies for each venom or cross-reacting antibodies that recognize similar or identical epitopes in both venoms. Unfortunately, patients often fail to identify the stinging insect which makes it difficult to distinguish cross-reactors from non cross-reactors. However, for economic reasons as well as for the benefit of the patients, it would be useful to identify complete cross-reactors. Methods: In this study we investigated 24 double-sensitized patients who were candidates for venom immunotherapy. Homologous and heterologous FEIA inhibition was carried out with honeybee (Apis mellifera) and wasp venom (Vespula spp.) preparations from two different providers. The inhibitor concentrations were ranging from 0 to 100 mug protein/ml. Results: Sera of 4 patients were completely cross-reacting for one venom (3 honeybee, 1 wasp), 8 patients were partially cross-reacting and 10 patients were not cross -reacting. Two patients were excluded from the study due to insufficient homologous inhibition. Data from specific IgE measurements, skin test, and clinical history were not useful for the identification of cross-reacting patients. Conclusion: FEIA inhibition is easy to perform and useful for the identification of patients with complete cross-reactivity. In these patients immunotherapy might be restricted to one venom which is beneficial for the patient and cost-effective.

Although the honey bee, Apis mellifera, has been considered the best pollinator for crops needing insect pollination, the current pandemic of varroatosis among honeybees highlights the need to find additional or alternative species as managed crop pollinators. Moreover, there is evidence that A. mellifera may not always be the most efficient pollinator. Introduction of A. mellifera into crops may be unnecessary, and even detrimental to non-Apis bee populations, which should be considered as an alternative for crop production improvement. Evaluating the pollination efficiency of non-Apis bees is one of the first steps in planning successful strategies for their conservation. In this study, we evaluated the pollination efficiency of Peponapis limitaris and A. mellifera in plots of Cucurbita moschata: pollen removal and deposition; pollinator visit frequency; and the pollinator visit-nectar production relationship. The results show P. limitaris to be the most efficient pollinator as: (1) both males and females remove and deposit almost four times as much pollen as A. mellifera; (2) they make significantly more floral visits than A. mellifera; and (3) their visit frequency shows a strong relationship to C. moschata nectar production during anthesis. Recommendations arising from this study are: (1) the introduction of A. mellifera be avoided in C. moschata crops; and (2) basic research be done on the biology of P. limitaris that contribute to its conservation and greater exploitation.

Complex odor recognition in the honeybee was investigated using two behavioral assays: (1) the conditioning of the proboscis extension (CPE) with restrained individuals, and (2) the observation of foragers visiting an artificial feeder in a flight room. Nine compounds, previously identified as oilseed rape flower volatiles, were tested either individually or in mixtures. Different sets of experiments were done to determine: (1) the acquisition rate of the nine compounds in the CPE assay, and (2) the discrimination of the individual compounds after conditioning to a mixture, using the CPE assay and free-flying foragers. After conditioning to a complex mixture, honeybees established a hierarchy among the components, with some of them accounting for a major part of the behavioral activity of the mixture. Both behavioral assays led to the same classification of compounds, indicating good agreement between discriminating abilities of restrained individuals and of a population of foragers. The key compounds for recognition of these mixtures were those that were well learned when presented individually. However, the recognition of some compounds was affected by the other components of the mixture, with the activity of some compounds being either enhanced or reduced.

Honeybees, Apis mellifera, were trained to detect coloured disks with either a strong or a weak intensity difference against the background. Green, blue, ultraviolet-reflecting white and grey papers were reciprocally combined as targets or backgrounds, providing strong chromatic and/or achromatic cues. The behavioural performance of the honeybees was always symmetrical for both reciprocal target/background combinations of a colour pair, thus showing that target detection is independent of whether the colour is presented as a background or as a target in combination with the other colour. Bright targets against dim backgrounds and vice versa were detected more reliably than dim target/background combinations. This result favours the general assumption that the detectability of a coloured stimulus increases with increasing intensity.

The flagellum of Apis mellifera (Hymenoptera, Apidae) consists of two mitochondrial derivatives, an axoneme and two accessory bodies. The mitochondrial derivatives are of unequal size and lie parallel to the axoneme. In the larger derivative four regions can be distinguished while in the smaller, only three. The region occurring only in the larger derivative consists of paracystalline material. The smaller mitochondrial derivative terminates anterior to the larger one. An extremely long centriolar adjunct is observed between the nucleus and the smaller mitochondrial derivative. This adjunct is compact, very electron dense and gradually tapers from base toward apex, finishing at the anterior extremity of the axonemal microtubules. In this flagellar region, there is only one accessory body present between the larger mitochondrial derivative and the axoneme. Anteriorly, the tips of the axonemal microtubules are inserted in a well developed mass of granular appearance. This material surrounds the nuclear base, separating it from the anterior end of the larger mitochondrial derivative. We believe that the structure identified here as a centriolar adjunct is homologous to that observed in Formicidae, Ichneumonoidea and Symphyta. Therefore, very probably, it is common to most Hymenoptera.

We investigated the relationships between the honey bee, Apis mellifera, and the parasitic mite Varroa jacobsoni in Mexico. In an 18-month survey of European honey bees (EHB) and Africanized honey bees (AHB), we showed that EHB were highly compatible with V. jacobsoni, while AHB were not as compatible. Furthermore, mite infertility ("parasite infectivity" factor), suspected to be the main factor of low AHB/V. jacobsoni compatibility in Brazil, was not observed in Mexico. The "intrinsic rate of natural increase" of mites did not differ significantly between host subspecies, indicating that the cause of low compatibility appears only at high parasite densities. The "carrying capacity" was twice as high in EHB as in AHB, indicating that the cause of low compatibility is possibly linked to honey bees' behavior. We hypothesize that the reason why V. jacobsoni is highly fertile on Mexican AHB (whereas it has low fertility on Brazilian AHB) may be that different strains of V. jacobsoni exist in the two countries.

Honeybees of the race Apis mellifera syriaca, which is autochthonous in Jordan, began brood rearing in the Jordan Valley at the early stages of nectar flow and pollen yield in late December and reached the entire season's maximum peak at the time of the main honey flow of citrus trees in March. In the Irbid region, brood rearing reached its peak at the beginning of the main honey flow of wild plants in June and ceased completely in November. Worker populations showed a double cycle during all years of the investigation. The highest worker population was found in April, with the second peak in June. Seasonal fluctuations in brood rearing activity and population of worker bees were fairly constant both in time and relative magnitude throughout all three years of the study.

In honeybees, the cuticular hydrocarbon profiles are partly genetically based and differ between subfamilies, which suggests that they might be used by the workers as labels for subfamily recognition. This ability could potentially form the basis for nepotistic conflicts between subfamilies that would be detrimental to the inclusive fitness of the colony. Here we have compared the subfamily hydrocarbon profiles of 5-day -old workers maintained in isolation with those kept in their parental colony. We demonstrate that the cuticular hydrocarbon profiles tend to be less distant between most subfamilies within the hive compared with those held in isolation. The main consequence of this partial homogenization of the majority of subfamily signatures may result in a reduction of the number of recognizable subfamilies in the colony. Nevertheless, a few subfamilies retain very distinct cuticular hydrocarbon profiles.

Renal failure by bee venom may be related to a malfunction of renal transporters. However, the effects of bee venom on apical membrane transporters of renal proximal tubular cells are not yet known. The aim of this study was to examine the effects of dried bee venom of Apis mellifera and its melittin on apical transporter activity of primary cultured rabbit kidney proximal tubule cells. Bee venom (1 mug/ml) decreased the cell viability and increased lactate dehydrogenase activity over 30-min treatments. Its effect was blocked by mepacrine or AACOCF3 (10-6 M; phospholipase A2 inhibitors). However, there was no effect on cell viability at a concentration of 0.01 mug/ml of bee venom. Thus, we investigated the effect of bee venom (1 mug/ml) on the activity of renal transporters at 30 min. Bee venom inhibited alpha-methyl-D -glucopyranoside, Pi, and Na+ uptakes, but increased Ca2+ uptake. These effects of bee venom were blocked by mepacrine or AACOCF3 (10-6 M), and bee venom-induced stimulation of Ca2+ uptake was also blocked by methoxyverapamil and nifedipine (L-type calcium channel blockers). In addition, bee venom increased (3H)-arachidonic acid release by 216% of that of control. In all experiments, bee venom melittin (0.5 mug/ml) had an identical effect to that of bee venom itself. In conclusion, bee venom inhibited, in part, alpha-MG, Pi, and Na+ uptakes through its melittin which increased Ca2+ uptake and arachidonic acid release in primary cultured rabbit renal proximal tubule cells.

We studied the influence of variance in reward volume on choice behaviour of honeybees, Apis mellifera carnica, by training bees to collect sucrose solution from four newly developed artificial feeders. The feeders were electromechanical devices, each controlled by a microprocessor, which monitored the experiments, controlled reward delivery and stored the data. The parameters that varied between the feeders were the amount and variance of reward. The four feeders were arranged in two pairs, with the two feeders in each pair set to the same reward parameters. Constant feeders offered a fixed amount of sucrose solution at each bee visit; variable feeders offered a normally distributed reward with a standard deviation equal to the mean. We tested three reward combinations under two variance conditions. The bees matched their choice frequencies to the mean amount of reward. This applied both to the constant and the variable feeders. Thus the bees were able to discriminate feeders by the amount of reward and were able to estimate the mean reward for the variable flowers. The proportion of immediate returns to the same feeder increased with the amount of sucrose solution imbibed at each visit, indicating that bees were able to perceive the amount of reward at each visit. However, there was no influence of variance on the choice behaviour of the bees, ruling out the possibility that bees are risk sensitive under these conditions. We discuss risk indifference in choice behaviour of bees in the context of several models of risk sensitivity.

The polyandrous mating behaviour of the honey bee queen increases the genotypical variability amongst her worker offspring. Microsatellite DNA analyses revealed a total of 16 subfamilies in one colony of honey bees. The subfamilies were represented in significantly different proportions in two subgroups of bees, water collecting bees and scenting bees, indicating a genetic component in task choice.

Pollination is an often overlooked but large cost factor in crop production. In spite of the high diversity of flowers, which requires an adequate diversity of pollinators, almost all animal pollination is simplistically ascribed to the manageable but often less efficient pollinator, the European honeybee, Apis mellifera L. In the case of poor pollination by honeybees, a number of costly techniques is applied to enforce fruit set-often with poor results. Finally, growers may resort to hand pollination, which greatly raises production costs. Knowledge of the appropriate pollinator is already available in many cases, however. This is demonstrated in this paper with examples spanning the whole range of pollination syndromes. To make this knowledge accessible, an expert-based Internet-accessible database is suggested.

Currently two hypotheses exist as to how insects process visual images, as photograph-like 'retinotopic-templates', or as a set of features extracted by the visual system. Several results obtained in honeybees cannot be reconciled with a retinotopic-template matching. (i) Bees discriminated between two patterns that should not be distinguished according to the template hypothesis. (ii) Bees preferred patterns that showed no overlap with the assumed template to patterns that had such an overlap. (iii) Bees showed a generalization of properties of the rewarded pattern to other patterns. Thus, in our paradigm, the bees must have used additional mechanisms and cues for the processing and classification of patterns.

The goal of this study was to develop a sensitive in vitro bioassay for quantification of the total esterase inhibiting potency of low concentrations of organophosphate and carbamate insecticides in relatively small rainwater samples. Purified acetylcholinesterase (AChE) from electric eel (Electrophorus electricus) and carboxylesterases from a homogenate of honeybee heads (Apis mellifera) were used as esterases, each having different affinities for the substrates S-acetylthiocholine-iodide (ATC) and N-methylindoxyl-acetate (MIA). MIA hydrolysis by honeybee homogenate was more sensitive to inhibition by organophosphate insecticides than ATC hydrolysis by purified AChE, although the latter parameter is often used for in vitro monitoring of esterase inhibitors. The higher sensitivity of carboxylesterases is attributed to the instant formation of a reversible Michaelis-Menten complex with the inhibitor, which competes with MIA for the active sites of the free enzymes. This dose-dependent instant inhibition can be quantified with kinetics for competitive inhibition at dichlorvos concentrations LGT 16 nM. At similar concentrations, purified AChE was not instantly inhibited, whereas both AChE and carboxylesterases were irreversibly and progressively inhibited at higher dichlorvos concentrations (IC5010min gtoreq 0.1 muM). Honeybee homogenate mediated MIA hydrolysis was applied as the most sensitive enzyme-substrate combination for experiments with fractionated extracts of 4 rainwater samples collected in a natural conservation area. Most esterase inhibiting potency was found in the polar methanol fraction, with recalculated concentrations equivalent to 12-125 ng dichlorvos per liter rainwater.

The authors estimated genetic polymorphism of the breed of Apis mellifera (middle-russian, caucasian grey mounainous, priokskaya) and Apis cerana (South-East Asia) by the RAPD-technology. It was detected breed- and species-specific markers which promote to identification of different breed, their selection and phylogenetic populational investigations of bee honey.

Colony size, honey yields and colony levels of infestation with Varroa jacobsoni of 30 queenright honeybee (Apis mellifera) colonies with naturally mated queens were evaluated over a two-year period. Workers taken from each colony were genotyped at four DNA-microsatellite loci to determine the level of polyandry. All queens mated with more than 10 drones (mean number of observed patrilines = 17.7 +- 5.23). We found significant correlations between colony size and honey yield and between colony sizes of two subsequent years. Analyses of variance revealed a strong impact of the breeding lines on the tested phenotypic traits. The impact of polyandry on colony honey yields was weak (p LGT 0.05, not significant when applying a Bonferroni adjustment) and 8% of the phenotype was determined by the effect of polyandry. The contribution of polyandry to colony size (0.25%) or levels of infestation with Varroa jacobsoni (0.09%) was even weaker in both test years. Likewise, we could not find any averaging effect of polyandry on the honey yield, size nor parasite load of honeybee colonies. Our data set does not resolve the question, whether polyandry and genetic diversity causes more productive colonial phenotypes. If colony level selection is an evolutionary force for polyandry, the effects are hard to detect in man-kept colonies headed by naturally mated queens.

The crude aqueous extract from the leaves of Casearia sylvestris, a plant found in Brazilian open pastures, was assayed for its ability to inhibit phospholipase A2 (PLA2) activity and some biological activities of bee and several snake venoms, and of a number of isolated PLA2s. The extract induced partial inhibition of the PLA2 activity of venoms containing class I, II and III PLA2s. When tested against the purified toxins, it showed the highest efficacy against class II PLA2s from viperid venoms, being relatively ineffective against the class I PLA2 pseudexin. In addition, C. sylvestris extract significantly inhibited the myotoxic activity of four Bothrops crude venoms and nine purified myotoxic PLA2s, including Lys-49 and Asp-49 variants. The extract was able to inhibit the anticoagulant activity of several isolated PLA2s, with the exception of pseudexin. Moreover, it partially reduced the edema-inducing activity of B. moojeni and B. jararacussu venoms, as well as of myotoxins MjTX-II and BthTX-I. The extract also prolonged the survival time of mice injected with lethal doses of several snake venoms and neutralized the lethal effect induced by several purified PLA2 myotoxins. It is concluded that C. sylvestris constitutes a rich source of PLA2 inhibitors.

ABSTRACT - The present study evaluated the occurrence of pollen types and the respective frequencies in honeys of Apis mellifera L. collected in an area with secondary forest at the School Farm of the Faculty of Agrarian Sciences of Para, in the municipality of Igarape-Acu, Para, Brazil. During the period of August 1995 to November 1996 honey samples coming from 5 beehives and calculated the percentage of pollen types. During the pollen analysis of the honeys 41 pollen types distributed in 23 families, 29 genera, 31 species and 10 undentified types were established. The most representative families in relation to the number of species were: Leguminosae-Mimosoideae (5) and Arecaceae (4). The species presenting dominant pollen types were Mimosa pudica L. (88%); Borreria verticillata G.F. Mey (74,8%) and Tapirira guianensis Aubl. (74,0%). The most important plant species of the secondary vegetation for honey production was Tapirira guianensis.

Studies were conducted on abundance and foraging behaviour of insect pollinators of raya crop and role of Apis mellifera in its pollination at Ludhiana during 1989-90. Apis dorsata Fab., A. mellifera L., A. florea Fab. and Andrena sp. consitituted 51.43, 23.77, 20 and 4.80 per cent of total bees caught on this crop. Apis dorsata was more active between 10-16 h while A. mellifera and A. florea were active between 11-16 h. On an average, A. mellifera, A. dorsata, and A. florea visited 14.06, 11.36 and 5.81 flowers/minute. One, two and five bee visits/flower by A. mellifera resulted in 65.5, 82.5 and 88.4 per cent pod setting. Intensive pollination of raya by A. mellifera increased the number of seeds/pod by 12.22 per cent, seed germination by 7.15 per cent and oil content by 8.31 per cent over natural pollination. When the visit of A. mellifera was excluded from the flowers, it resulted in decrease of these parameters by 13.57, 0.23 and 2.39 per cent respectively.

Different modes of cell death have been revealed in the regressing hypopharyngeal glands of worker honey bees. The hypopharyngeal gland, which is well developed in young nursing bees to produce protein for larval food, was seen to regress naturally in foraging adult worker bees. A range of techniques including histology, cytochemistry, in situ TUNEL, Annexin V and Comet assays indicated that cells within the gland demonstrate progressive symptoms of apoptosis, necrosis and a vacuolar form of programmed cell death. The latter mode of cell death did not display chromatin margination, but was accompanied by an enhanced level of autophagic and hydrolytic activity in which a cytosolic source of acid phosphatase became manifest in the extra-cisternal spaces. Normal and annexin-positive cells were found to occur in the younger nursing bees, whilst necrosis and an aberrant vacuolar type of apoptosis predominated in the older foraging bees. The relevance of these results to the classification of programmed cell death is discussed.

Hox genes are known to control the identity of serially repeated structures in arthropods and vertebrates. We analyzed the expression pattern of the Hox genes Deformed (Dfd), Sex combs reduced (Scr), Antennapedia (Antp), and Ultrabithorax/abdominal-A (Ubx/abd-A) from the honey bee Apis mellifera. We also cloned a cDNA with the complete coding region of the Antennapedia gene from Apis. Comparison with Antp proteins from other insect species revealed several regions of homology. The expression patterns of the isolated Hox genes from Apis showed that the original expression patterns of Dfd, Scr, and Antp appear between late blastoderm and early germ band stage in a temporal and spatial sequence. Each of them shows up as a belt, spanning approximately two segment anlagen, Dfd in the anterior gnathal region, Scr in the posterior gnathal and anterior thoracic region, and Antp in the thoracic region. Following expansion of the Antp domain in the abdomen as a gradient towards the posterior, Ubx/abd-A expression appears laterally in the abdomen. During gastrulation and in the germ band stage the domains of strong expression do not overlap any more, but touch each other. After gastrulation the borders of the expression domains partly correlate with parasegment and partly with segment boundaries. Laterally, gaps between the domain of each gene may show no expression of any of the genes examined.

This study was made on the foraging pattern of three honeybee species viz., Apis dorsata F., Apis mellifera L. and Apis florea F. on eight cultivars of oilseed crops viz., brown sarson (Brassica campestris L. var. brown sarson cv. BSH-1), yellow sarson (Brassica campestris L. var. yellow sarson cv. YSPB-1), toria (Brassica campestris L. var. toria TH-68), raya (B. juncea Czem and Coss cvs. RH-8812, RH-819 and RH-30), taramira (Eruca sativa Lam. cv. T-27) and sunflower (Helianthus annuus L.), during their entire blooming period. The results showed that honeybee visitation frequency was low at the time of initiation of flowering, then increased gradually and reached a peak during the peak flowering time. This peak continued for over two weeks and then declined suddenly with the decline in flowering on these crops. This pattern of honeybee visitation provided a useful information for selecting the time of deployment of honeybee colonies on these crops for their pollination. In this study also the three honeybee species were found to show clear preferences for the various crops and seemed to partition the food resources.

The diurnal foraging pattern of three honeybee species viz., giant honeybee (Apis dorsata F.), European honeybee (Apis mellifera L.) and little honeybee (Apis florea F.) was studied on eight cultivars of oilseed crops viz., brown sarson (Brassica campestris L. var. brown sarson cv. BSH-1), yellow sarson (B. campestris L. yellow sarson cv. YSPB-1), toria (B. campestris L. var. toria cv. Th-68), raya (B. juncea Czern AMPERSAND Coss cvs. RH -8812, RH-819 and RH-30), taramira (Eruca sativa Lam. cv. T-27) and sunflower (Helianthus annuus L.). The honeybee visitation frequency was low in the morning, then reached a peak between 1100-1300 h and again declined in the evening. The differences between the activity patterns of three honeybee species were also recorded. The significance of these results has been discussed.

This study was designed to determine the effect of D-002, a natural product isolated and purified from beeswax (Apis mellifera), on gastric mucus composition on ethanol-induced ulcer in rats. The morphology of the lesions was analysed histologically, and morphometric analysis of gastric -gland content in total glycoprotein and sulphated macromolecules were done. Oral pretreatment with D-002 at 5 and 25 mg kg-1 1 before oral administration of ethanol at 60%, produced a significant increase in the amount of gastric mucus and total protein. The histomorphometric evaluation of the gastric damage at the same doses showed a significant increase in neutral glycoproteins and sulfated macromolecules. It is concluded that enhancement of the quantity and quality of the mucus could partly explain the gastroprotective effect of D-002.

The venom of the honeybee Apis mellifera induces cardiovascular dysfunction. As its effects on coronary arteries have not yet been described, we studied the effects of the whole honeybee venom (non -volatile part) in the isolated porcine left anterior descending coronary artery (LAD) and the influence of L-type Ca2+ channel blocker, lacidipine, upon the venom effects in LAD. The venom produced concentration dependent contractions (7-70 mug/ml) of the porcine LAD; maximal effect of the venom was approximately the same as the effect of 30 mM KCl. Lacidipine concentration dependently (0.1-10 muM) and significantly (P ltoreq 0.05) decreased the venom-induced vasoconstriction. The results indicate the involvement of L-type Ca2+ channels in coronary contraction, induced by bee venom.

In fact of season alternation, a bee colony presents the whole year round a succession of development states, corresponding to the annual biological cycme. We are relatively well informed at present of the behavioral variation and differences between geographic races. In the world, it's an accepted fact for example that colony losses occur in winter but in Tunisia, Apis mellifera intermissa has to endure severe summer which reduce the number of colonies. Summer colony deaths were very important specially on august and september. So, we lose every year: + 5,1% of bee colonies in january (25,5% of the total colony losses per year) + 2,8% of bee colonies in may (14,6% of the total colony losses per year) + 3,4% and 7,9% of bee colonies in august and september (14,7% and 34,3% of the total colony losses per year). To reduce the summer heavy losses (49%), we peconise to beekeepers to provide an artificial bee feed to bee colonies in summer after the honey production (in august). Summer feed help colonies to endure severe summer. It's equally very important to not forget the winter feed which is distribute to honeybees colony at november in order to help them to survive in winter.

In the insect sperm flagellum, an extra set of nine additional microtubules, named accessory tubules, is present surrounding the axoneme. Using a sarcosyl/urea extraction, we were able to fractionate the microtubular cytoskeleton of the sperm flagellum of the insect Apis mellifera resulting in the dissociation of the axonemal microtubule protein components and the accessory tubules. This has allowed us to compare the tubulin isoform content of axonemal microtubules and accessory tubules by immunoelectron microscopy and immunoblotting using a panel of monoclonal antibodies directed against different tubulin post -translational modifications (PTMs). All the PTMs occurring in axonemal tubulin are also present in accessory tubules, which indicates the close relativeness of accessory tubules to axonemal rather than to cytoplasmic microtubules. However, our results demonstrate the presence of significant differences in the tubulin isoform content of axonemal microtubules and accessory tubules. First, the tubulin tyrosination extent of accessory tubules is far lower than that of axonemal microtubules, thus confirming at the molecular level their morphogenetic origin as outgrowths from the B -subtubule of each microtubular doublet. Second, although polyglycylation seems to occurr at the same extent in both microtubular systems, alpha -tubulin exhibits a larger amount of monoglycylated sites in axonemal microtubules than in accessory tubules. Third, a greater amount of beta -tubulin molecules is glutamylated in axonemal microtubules than in accessory tubules. Moreover, highly acidic isoforms, likely molecules with longer polyglutamate side chains, are present only in axonemal microtubules. Taken together, our data are indicative of a higher level of tubulin heterogeneity in axonemal microtubules than in accessory tubules. They also show a segregation of post-translationally modified isoforms between accessory tubules and axonemal microtubules and suggest the implication of PTMs in the functional specialization of the two microtubular systems.

Propolis, a resinous hive product collected by Apis mellifera bees, has been used for thousands of years in folk medicine. Ethanolic extracts of propolis (EEP) have been shown to inhibit the activity of a mixture of crude glucosyltransferase (Gtf) enzymes in solution. These enzymes synthesize glucans from sucrose, which are important for the formation of pathogenic dental plaque. In the present study, the effects of propolis from two different regions of Brazil on the activity of separate, purified Gtf enzymes in solution and on the surface of saliva-coated hydroxyapatite (sHA) beads were evaluated. The EEP from Minas Gerais (MG; Southeastern Brazil) and Rio Grande do Sul (RS; Southern Brazil) were tested for their ability to inhibit the enzymes GtfB (synthesis of insoluble glucan), GtfC (insoluble/soluble glucan) and GtfD (soluble glucan). The effects of propolis on Gtf from Streptococcus sanguis (soluble glucan synthesis) was also explored. The EEP from both regions effectively inhibited the activity of all Gtfs in solution (75-95%) and on the surface of sHA beads (45-95%) at concentrations between 0.75 and 3.0 mg of propolis/ml. However, the two samples of propolis showed different levels of inhibition on each of the enzymes tested. In general, EEP RS demonstrated a significantly higher inhibitory activity on GtfB and C activities (both solution and surface assays) than EEP MG at concentrations between 0.047 and 0.187 mg/ml (p LGT 0.05). EEP MG, on the other hand, exhibited a greater inhibitory effect on the activities of surface GtfD (at 0.375, 0.75 and 1.5 mg/ml) and S. sanguis Gtf (at 1.5 and 3.0 mg/ml; p LGT 0.05). These data indicate that EEP is a potent inhibitor of Gtf enzymes in solution and adsorbed on an experimental pellicle; however, its effect on Gtf activity is variable depending on the geographical origin of the propolis samples. There is a need to identify the active compounds of propolis.

Colonies of A. m. capensis, A. m. scutellata and their natural hybrids were dequeened and debrooded. The ratio of worker/drone cell construction and the sex of laying worker offspring were determined for 26 colonies. All A. m. capensis laying workers were thelytokous and all A. m. scutellata arrhenotokous. 42.1% of the hybrid colonies produced only female offspring while none produced only male offspring. This shows a significant advantage for thelytokous laying workers to become reproductively dominant in hybrid colonies. A. m. capensis colonies built only worker cells and A. m. scutellata only drone cells. Hybrid colonies produced either both cell types or only worker cells according to the mode of laying worker reproduction. In all colonies where laying workers produced male offspring drone cell building was found. Our data strongly indicates that the mode of worker reproduction holds important consequences for cell construction and reproductive dominance.

Honeybee colonies were evaluated for hygienic behaviour using a pin-killed brood assay. Presence and absence of visual symptoms of brood diseases were recorded. Colonies that removed more than 80% of dead brood after 24 hours were selected for queen and drone production and new colonies were evaluated for hygienic behaviour. This procedure was repeated yearly from 1992 through 1997. The degree of total hygienic behaviour (brood removed) and partial hygienic behaviour (brood uncapped but not totally removed) were determined. Colonies were classified as hygienic and non-hygienic and these data were related to the incidence of brood diseases. Total hygienic behaviour increased in the population after four years of selection on queens without mating control from 66.25% in 1992 to 84.56% in 1997. Hygienic colonies had a lower frequency of brood diseases when compared to non-hygienic colonies. It is suggested that this trait can be used as a selection criterion in queen breeders' apiaries.

The honeybee populations of Africa classified as Apis mellifera scutellata Lepeletier were analysed morphometrically using multivariate statistical techniques. The collection consisted of nearly 15,000 worker honeybees from 825 individual colonies at 193 localities in east Africa, extending from South Africa to Ethiopia. Factor analysis established one primary cluster, designated as A. m. scutellata. Morphocluster formation and inclusivity (correct classification) are highly sensitive to sampling distance intervals. Within the A. m. scutellata region are larger bees associated with high altitudes of mountain systems which are traditionally classified as A. m. monticola Smith, but it is evident that these bees do not form a uniform group. Variance characteristics of the morphometric measurements show domains of significantly different local populations. These high variance populations mostly occur at transitional edges of major climatic and vegetational zones, and sometimes with more localised discontinuities in temperature. It is also now evident that those A. m. scutellata introduced nearly fifty years ago into the Neotropics were a particularly homogenous sample, which exhibited all the traits expected in a founder effect or bottleneck population.

Antibiotic extender patties, consisting of sugar, vegetable shortening, and oxytetracycline (OTC, usually as the hydrochloride), are used for treatment/prevention of foulbrood in honey bees. An analytical method was developed to determine the concentration in the patties and to allow a study of deterioration over time. Trituration of a sample with EDTA -treated C18 silica gel, removal of the shortening with isooctane, and elution of the OTC with methanol/acetonitrile gave a solution that could be analyzed by HPLC. Different concentrations and total amounts of OTC have been recommended by different authors. Not all newly-procured samples contained the same level of OTC, and the concentration decreased about 4% per year with storage at room temperature.

Seven Apis mellifera carnica queens were instrumentally inseminated with the semen of their own sons. Diploid drone offspring of these queens were raised using two established techniques including elaborate laboratory manipulations, and a new approach. The new approach, based on routine beekeeping, uses small mating nuclei, which rear diploid drones to the adult stage late in the season. No labour and cost intensive feeding, nor grafting and incubation steps are needed. The ploidy level of the drone offspring was evaluated using seven DNA microsatellites. All drones reared by the elaborate techniques and more than 90% of the drones reared in a small mating nucleus were definitely diploid. This technique allows for easy and simple diploid drone rearing even in research groups with no sophisticated equipment.

The mortality of honey bee larvae and pupae reared in vitro caused by various combinations of oral inoculation with Paenibacillus larvae larvae spores, acute paralysis virus (APV), and infestation with Varroa jacobsoni was studied. The effect of the mite itself and the mite acting as a vector of APV on the mortality of larvae and pupae was investigated. Mortality caused by P. l. larvae ranged from 25 to 55% depending on spore dose. Oral inoculation with APV caused 9% mortality, which was not additive to the mortality caused by P. l. larvae. P. l. larvae did not induce the activation of APV infection. The mortality caused by V. jacobsoni itself was 25%, and by mites transmitting APV, 55%. Neither the mites themselves or the mites transmitting APV had an additive effect on mortality caused by P. l. larvae. The study suggests that APV transmitted by mites is the most significant cause of mortality of the treatment combinations tested. The results do not suggest that the mite itself or the mites transmitting APV act as a stress factor provoking clinical symptoms of American foulbrood (AFB) in individual larvae in the in vitro rearing system.

The objective of the present work was to study the pollination in basil (Ocimum basilicum), in order to verify its attractiveness for honey bees (Apis mellifera), the most frequent insects, as well as its behaviors and effects on the production of seeds. The basil flower lasted, on average, 30 hours, from the bud phase until the flower withered. The number of flowers opened by inflorescence was, on average, 5,65 +- 1,42 flowers, and the inflorescence presented a mean of 160 +- 11,73 flowers-buds. The basil was visited mainly by africanized honey bee (98,0%), followed by the native bee Augochloropsis electra-Halictidae (2,0%) and sporadic visits of Diptera and Lepidoptera. All insects collected only nectar in the culture and delayed of 1 to 3 seconds in each flower. The frequency of the honey bee increased in elapsing of the day to 14:00, decreasing soon after accompanying the curve of the temperature sets registered in the days of the experiment and also the increase in nectar concentration of the flowers. The basil can be considered an important nectar source to africanized honey bees.

Honey bees, Apis mellifera, have been used for several years to pollinate caged plant species maintained at the USDA-ARS North Central Regional Plant Introduction Station (NCRPIS), Ames, Iowa. Because maintaining large numbers of honey bees is expensive and time consuming, we began looking in 1995 for other pollinator species that can be easily managed and less expensive to maintain than A. mellifera. One species we tested was the hornfaced bee, Osmia cornifrons, a solitary bee imported from Japan in the late 1970s. We also tested a mixture of native bumblebees, Bombus bimaculatus and B. impatiens, which are native to the U.S. Midwest. These bee species were compared in field cages to determine which would produce the greatest number of seeds/plant on the wild annual sunflower, Helianthus petiolaris. After 2 years testing, honey bees consistently produced more seeds/plant than did the other bees tested.

Apis mellifera mellifera L. and its hybrid with a Taiwanese race have the smallest brood area as compared with Apis mellifera ligustica Spin. and Taiwanese races, while A. m. m. has about 1.5 times the honey storage of the latter two races during winter in Taiwan. A. m. l. colonies showed significant brood rearing behavior during winter. During the longan (Euphoria longana) nectar flow season, A. m. m. had moderate honey production which did not significantly differ from that of the other tested races. However, its royal jelly production was significantly lower, even for those colonies fed green algae as a supplement mixed in syrup or in pollen paste, than that of A. m. l. and the screened Taiwanese superior royal jelly races. The screened Taiwanese superior royal jelly race shows great potential for both royal jelly and honey production.

Five proteins were expressed in larval honey bee fat bod incubated in vitro in response to heat shock, as shown by SDS-PAGE and fluorography. The large heat shock proteins (82, 70 kDa) were inducible throughout the 5th instar whereas the small ones (29, 26, 16 kDa) were inducible only in certain phases of this instar. The synthesis of these HSPs was accompanied by generalized inhibition of overall protein synthesis and secretion in the culture medium. Fluorograms showed that the 76 and 74 kDa proteins were strongly inhibited by heat treatment. Western blots using a mouse monoclonal antibody against HSP72 and HSC73 permitted the inference that the 70 kDa larval protein accumulated in the honey bee fat body in response to heat shock corresponds to the HSP72 isoform. The Western blots also showed a 70 kDa faint band in fat bodies incubated at the control temperature (34 degreeC). This protein, also detected in incubation media independently of the temperature used, was interpreted as being the constitutively synthesized and secreted HSC73 isoform.

Two genetic markers (the mtDNA COI-COII intergenic region and the microsatellite A7) with high levels of variability in South African and European honey bees were analyzed in wild swarms of Africanized honey bees (Apis mellifera) from Costa Rica. Allelic or haplotypic frequencies revealed high levels of genetic variability at these loci in this population. Most of the alleles were African alleles, although some European-derived alleles were also present. Differences in the frequencies of African alleles between African and Africanized samples were minor, which could be explained by founder effects occurring during the introduction of African honey bee populations into South America.

Melittin, the main component of bee venom of Apis mellifera, contains a proline at position 14, which is highly conserved in related peptides of various bee venoms. To investigate the structural and functional role of Pro14 a melittin analogue was studied where proline is substituted by an alanine residue (P14A). The investigations were focussed on: (i) the secondary structure in aqueous solution and membranes; (ii) the self -association in solution; (iii) the binding to POPC membranes; and (iv) the P14A-induced leakage and pore formation in membrane vesicles. Circular dichroism and gel filtration experiments showed that P14A exists at concentrations LGT 12 muM in monomeric form with an alpha-helicity of 28 +- 7%. A further increase in peptide concentration leads to the formation of large aggregates consisting of 9 +- 1 monomers. While binding studies with POPC vesicles revealed for P14A a stronger binding affinity towards membranes than for melittin, the peptide-induced leakage of fluorescent markers from vesicles was less efficient for P14A than for melittin. Furthermore, an unexpected efflux behaviour at high values of bound P14A was observed which indicated that the pore formation kinetics for P14A is more complex than it was reported for melittin. The different features of P14A in aggregation, binding and efflux compared to melittin are mainly ascribable directly to structural changes caused by the proline fwdarw alanine substitution. Furthermore, the results indicate an improved screening of the positively charged residues of P14A by counterions which contributes additionally to the observed differences in peptide activities. It is suggested that the presence of proline in melittin is not only of structural importance but also influences indirectly the electrostatic properties of the native peptide.

The role of glutamate in the central nervous system of invertebrates is poorly understood. In the present study we examined the effects of a glutamate transporter inhibitor, L-trans-2,4-pyrrolidine dicarboxylate (L -trans-2,4-PDC), on memory formation in the honeybee following a three -trial classical conditioning of the proboscis extension reflex (PER). Pre -training injections of the drug have no effect on acquisition and short -term (1 h) memory, but impair long-term (24 h), associative olfactory memory in a dose-dependent manner. This effect is transient and the amnesiac individuals can be re-trained successfully 48 h after injections. Our results suggest that glutamatergic neurons in the honeybee brain, in particular those found in the mushroom bodies (MBs), may be part of the circuitry involved in processing of long-term olfactory memory. Such a role for this neurotransmitter is consistent with our previous results showing that glutamate and glutamate transporter(s) are localised in regions of the honeybee brain implicated in higher order processing.

1. Waggle dances of honey-bees (Apis mellifera L.) were decoded to determine where and how far the bees foraged during the blooming of heather (Calluna vulgaris L.) in August 1996 using a hive located in Sheffield, UK, east of the heather moors. The median distance foraged was 6.1 km, and the mean 5.5 km. Only 10% of the bees foraged within 0.5 km of the hive whereas 50% went more than 6 km, 25% more than 7.5 km and 10% more than 9.5 km from the hive. 2. These results are in sharp contrast with previous studies in which foraging distances were much closer to the hive. In May 1997 the mean foraging distance was 1 km, showing that long -range dancing is not the rule in Sheffield. 3. The observed foraging distances described in this study may not be exceptional in a patchy environment where differences in patch size and patch quality are large. When travel distances to patches are large, distant patches can probably be utilized only by individuals that live in groups and recruit foragers to the patches found. Only then are the benefits of scouting for distant patches high enough to enable the exploitation of these patches.

In honeybees, as in other highly eusocial species, tasks are performed by individual workers, but selection for worker task phenotypes occurs at the colony level. We investigated the effect of colony-level selection for pollen storage levels on the foraging behavior of individual honeybee foragers to determine (1) the relationship between genotype and phenotypic expression of foraging traits at the individual level and (2) how genetically based variation in worker task phenotype is integrated into colony task organization. We placed workers from lines selected at the colony level for high or low pollen stores together with hybrid workers into a common hive environment with controlled access to resources. Workers from the selected lines showed reciprocal variation in pollen and nectar collection. High-pollen-line foragers collected pollen preferentially, and low-pollen-line workers collected nectar, indicating that the two tasks covary genetically. Hybrid workers were not intermediate in phenotype, but instead showed directional dominance for nectar collection. We monitored the responses of workers from the selected strains to changes in internal (colony) and external (resource) stimulus levels for pollen foraging to measure the interaction between genotypic variation in foraging behavior and stimulus environment. Under low -stimulus conditions, the foraging group was over-represented by high -pollen-line workers. However, the evenness in distribution of the focal genetic groups increased as foraging stimuli increased. These data are consistent with a model where task choice is a consequence of genetically based response thresholds, and where genotypic diversity allows colony flexibility by providing a range of stimulus thresholds.

Background: The purpose of this experiment was to test the feasibility of creating an animal model of ethanol consumption using social insects. Honey bees were selected as the model social insect because much is known about their natural history, physiology, genetics, and behavior. They are also inexpensive to procure and maintain. Of special interest is their use of communication and social organization. Methods: Using both between- and within-experiment designs, studies were conducted with harnessed foragers to determine whether honey bees would consume ethanol mixed with sucrose (and, in some cases, water). Shuttle-box and running-wheel studies were conducted to examine the effect of ethanol on locomotion. The effect of ethanol on stinging behavior in harnessed foragers was investigated. The effect of ethanol on Pavlovian conditioning of proboscis extension was also investigated. Finally, in a self-administration study, foraging honey bees were trained to fly to an artificial flower containing ethanol. Results: (1) Harnessed honey bees readily consume 1%, 5%, 10%, and 20% ethanol solutions; (2) 95% ethanol will also be consumed as long as the antennae do not make contact with the solution; (3) with the exception of 95% ethanol, consumption as measured by contact time or amount consumed does not differ in animals that consume 1%, 5%, 10%, and 20% ethanol solutions; (4) exposure to a lesser (or greater) concentration of ethanol does not influence consumption of a greater (or lesser) concentration; (5) consumption of 10% and 20% ethanol solutions decreases locomotion when tested in both a shuttle-box and running-wheel situation; (6) consumption of 1%, 5%, 10%, and 20% ethanol does not influence stinging behavior in harnessed foragers; (7) ethanol solutions greater than 5% significantly impair Pavlovian conditioning of proboscis extension; and (8) free-flying honey bee foragers will readily drink from an artificial flower containing 5% ethanol. Conclusions: The experiments on consumption, locomotion, and learning suggest that exposure to ethanol influences behavior of honey bees similar to that observed in experiments with analogous vertebrates. The honey bee model presents unique research opportunities regarding the influence of ethanol in the areas of language, social interaction, development, and learning. Although the behavioral results are interesting, similarity between the physiologic effects of ethanol on honey bees and vertebrates has not yet been determined.

Juvenile hormone (JH) is considered the prime endogenous signal for the induction of queen development in honey bees (Apis mellifera L.). At the beginning of the last (5th) larval stadium, worker corpora allata synthesize less JH than queen corpora allata as a consequence of a limited production of JH precursors and a caste- and stage-specific block of the terminal step in JH biosynthesis. As previously shown, the Manduca sexta allatotropin stimulates JH biosynthesis in honey bee corpora allata in a dose-dependent and reversible manner, but can not overcome the stage -specific block in the terminal step of JH biosynthesis that is typical for worker early 5th instars. In experiments with M. sexta allatotropin and with the JH precursor farnesoic acid, we found characteristic stage -specific differences in their effects on JH biosynthesis. From the end of the spinning stage on, corpora allata could be stimulated by farnesoic acid to a much higher extent than in earlier developmental stages, suggesting a sudden increase in epoxidase activity. Manduca sexta allatotropin, however, stimulated corpora allata activity until the end of the spinning stage, at which time the corpora allata become suddenly insensitive. These data suggest that in worker larvae, important changes in the regulation of the terminal enzymatic steps in JH biosynthesis occur at the transition from the spinning stage to the prepupal stage. However, the analysis of in vitro activities of the involved enzymes, O -methyltransferase and methyl farnesoate epoxidase, remained inconclusive.

The effects of a new variety of propolis, from Northeastern Brazil (BA), on growth of mutans streptococci, cell adherence, and water-insoluble glucan (WIG) synthesis were evaluated. Propolis from Southeastern (MG) and Southern (RS) Brazil were also tested as an extension of our previous work. Ethanolic extracts of propolis (EEP) were prepared and analyzed by reversed-phase HPLC. For the antibacterial activity assays, minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of EEPs against Streptococcus mutans, S. sobrinus, and S. cricetus were determined. Cell adherence of S. mutans and S. sobrinus to a glass surface was measured spectrophotometrically at 550 nm. WIG synthesized from sucrose by glucosyltransferase (Gtf) was extracted and quantified by the phenol-sulfuric method. The HPLC profile of the new variety of propolis was entirely different from Southeastern and Southern propolis. Neither flavonoid aglycones nor p-coumaric acid were detected in EEP BA. All EEPs demonstrated biological activities against mutans streptococci; EEP BA showed the highest potency in all in vitro parameters evaluated in this study. The ranges of MIC values were 50 (EEP BA)-400 mug/ml (MG), for S. mutans; and 25 (BA)-400 mug/ml (MG), for S. sobrinus and S. cricetus. The bactericidal concentration of EEPs was four to eighttimes the MIC values. The adherence of S. mutans and S. sobrinus cells and WIG synthesis were markedly inhibited by EEPs, demonstrating significant inhibition at all concentrations compared with the control (80% ethanol) (p LGT 0.05). EEP BA showed 80% inhibition of cell adherence and WIG synthesis at concentrations as low as 12.5 and 7.8 mug/ml, respectively. The results show that the new variety of propolis was exceptionally effective in all in vitro parameters tested against mutans streptococci; biological effects of propolis are likely not to be due solely to flavonoids and (hydroxy)cinnamic acid derivatives.

Crude combwax of six various honey bee species have been analyzed by high -temperature gas chromatography (HTGC)-chemical ionization mass spectrometry after a two-step silylation procedure. An optimized chromatographic procedure, described previously, enables the separation of high-molecular mass lipid compounds resulting in a characteristic fingerprint of the combwaxes of different honeybee species. The coupling of HTGC to mass spectrometry requires appropriate instrumentation in order to achieve sufficient sensitivity at high elution temperatures and avoid loss of chromatographic resolution. Chemical ionization was carried out using methane as reagent gas in order to determine the molecular mass of the individual compounds by means of abundant quasi molecular ions. To confirm the presence of unsaturated wax esters, ammonia was used as reagent gas. More than 80 lipid constituents were separated and characterized by their mass spectra. Representative chemical ionization mass spectra of individual compounds are presented. Both, HTGC-flame ionization detection data and the results of the HTGC-mass spectrometric investigations enabled a rapid profiling of the individual classes of compounds in crude combwaxes.

During house hunting, honeybee, Apis mellifera, workers perform the vibration signal, which may function in a modulatory manner to influence several aspects of nestsite selection and colony movement. We examined the role of the vibration signal in the house-hunting process of seven honeybee swarms. The signal was performed by a small proportion of the older bees, and 20% of the vibrating bees also performed waggle dances for nestsites. Compared to non-vibrating controls, vibrating bees exhibited increased rates of locomotion, were more likely to move into the interiors of the swarms, and were more likely to fly from the clusters and perform waggle dances. Recipients responded to the signal with increased locomotion and were more likely than non-vibrated controls to fly from the swarms. Because vibration signals were intermixed with waggle dances by some vibrators, and because they stimulated flight in recipients, the signals may have enhanced nestsite scouting and recruitment early in the house-hunting process. All swarms exhibited increased vibration activity within 0.5-1 h of departure. During these final periods, numerous vibrating bees wove repeatedly in and out of the clusters while signaling and motion on the swarms increased until it culminated in mass flight. The peaks of vibration activity observed at the end of the house-hunting process may therefore have activated the entire swarm for liftoff once a new nestsite had been selected. Thus, the vibration signal may help to integrate the behavior of numerous groups of workers during nestsite selection and colony relocation.

Honey bees (Apis mellifera adansonii) in a Gabonese forest were marked at feeding stations having odor beacons (vanilla extract), offering 4 oz. of 20-50% scented sugar solution. Experiments were conducted for 28 days while 7380 total bees were marked at stations along a 2 km forest trail. Stations each 300 m were used to score honey bee movement to new sites. During 706 station observations, 57% included bees that had shifted feeding sites by up to 1.6 km, with negative logarithmic distribution away from the marking site. Site shifts within a single day showed a similar range, minimum times of 14-18 min for 300-600 m, and a linear relationship between distance and time elapsed since marking (P = 0.001, r2 = 0.41). These data suggest honey bees may provide gene flow to plant populations within an area of 1.8 km2 and between individuals separated by RGT 1.5 km. Further analysis suggests bees sometimes trapline 300-600 m, perhaps without first returning to the nest, but rarely do so for longer distances.

Evidence of tool use for foraging for honey by chimpanzees in Bwindi -Impenetrable National Park, Uganda, is reported. These are the first records of tool use by chimpanzees in this region of the Albertine Rift. Tools of two types were found at sites of bee activity. Chimpanzees apparently use small stick tools to forage for the honey of a stingless bee (Meliponula bocandei (Trigonidae)) that nests in tree cavities and also in subterranean holes. They use significantly larger, thicker tools to assist in foraging for honey of African honeybees (Apis mellifera).

Lethal Toxin Neutralizing Factor (LTNF), isolated from opossum with having molecular weight 63 kDa, is a potent antidote for animal, plant, and bacterial toxins. This communication deals with the identification of a small fragment of LTNF eliciting the anti-lethal activity of animal, plant, and bacterial toxins when tested in mice. Purified LTNF was treated with trypsin to cause fragmentation at the arginine and lysine sites. The fragments were separated by high-performance liquid chromatography (HPLC) and were tested against anti-LTNF for binding affinity by enzyme-linked immunosorbent test (ELISA). The fragment showing the most binding to anti -LTNF was sequenced. Synthetic peptides consisting of 15 and 10 amino acids from the N-terminal were constructed and designated as LT-15, with amino acid sequence Leu-Lys-Ala-Met-Asp-Pro-Thr-Pro-Pro-Leu-Trp-Ile-Lys -Thr-Glu, and LT-10, with sequence Leu-Lys-Ala-Met-Asp-Pro-Thr-Pro-Pro -Leu. Death due to intramuscular (IM) injection of predetermined lethal doses of toxins derived from animal, plant, and bacteria was prevented treating the mice with synthetic peptides LT-15 and LT-10. The lethality was inhibited when the treatment was given before or after the toxin injection. Synthetic LTNF can be made in abundance and should become a universal therapy against intoxication caused by animal, plant, and bacteria.

Varroa jacobsoni was first described as a natural ectoparasitic mite of the Eastern honeybee (Apis cerana) throughout Asia. It later switched host to the Western honeybee (A. mellifera) and has now become a serious pest of that bee worldwide. The studies reported here on genotypic, phenotypic and reproductive variation among V. jacobsoni infesting A. cerana throughout Asia demonstrate that V. jacobsoni is a complex of at least two different species. In a new classification V. jacobsoni is here redefined as encompassing nine haplotypes (mites with distinct mtDNA CO-I gene sequences) that infest A. cerana in the Malaysia-Indonesia region. Included is a Java haplotype, specimens of which were used to first describe V. jacobsoni at the beginning of this century. A new name, V. destructor n. sp., is given to six haplotypes that infest A. cerana on mainland Asia. Adult females of V. destructor are significantly larger and less spherical in shape than females of V. jacobsoni and they are also reproductively isolated from females of V. jacobsoni. The taxonomic positions of a further three unique haplotypes that infest A. cerana in the Philippines is uncertain and requires further study. Other studies reported here also show that only two of the 18 different haplotypes concealed within the complex of mites infesting A. cerana have become pests of A. mellifera worldwide. Both belong to V. destructor, and they are not V. jacobsoni. The most common is a Korea haplotype, so-called because it was also found parasitizing A. cerana in South Korea. It was identified on A. mellifera in Europe, the Middle East, Africa, Asia, and the Americas. Less common is a Japan/Thailand haplotype, so-called because it was also found parasitizing A. cerana in Japan and Thailand. It was identified on A. mellifera in Japan, Thailand and the Americas. Our results imply that the findings of past research on V. jacobsoni are applicable mostly to V. destructor. Our results will also influence quarantine protocols for bee mites, and may present new strategies for mite control.

Pairs of black patterns on a white background, one rewarded the other not, were presented vertically each in one arm of a Y-maze. During training the locations of the black areas were changed every 5 min to prevent the bees using them as cues, but cues from edges were kept consistent. Bees detect orientation even in a gradient that subtends 36degree from black to White (normal to the edge). Orientation cues in short lengths of edge are detected and summed on each side of the fixation point, irrespective of the lay-out of the pattern. Edges at right angles reduce the total orientation cue. The polarity of edges in a sawtooth grating is weakly discriminated, but not the orientation of a fault line where two gratings meet. Edge quality can be discriminated, but is not recognised in unfamiliar orientations. When spot location is excluded as a cue, the orientation of a row of spots or squares which individually provide no net orientation cue is not discriminated. In conclusion, when locations of black areas are shuffled, the bees remember the sum of local orientation cues but not the global pattern, and there is no re-assembly of a pattern based on differently oriented edges. A neuronal model consistent with these results is presented.

This paper presents the results of a long-term study on the genetic status of feral Yucatecan honey bees combining analyses of morphological, allozyme and mitochondrial DNA (mtDNA) characters. The results showed that feral Yucatecan colonies had varying degrees of association between European/African morphology, allozymes and haplotypes. Frequencies of European markers varied between years, but markers (polymorphisms) of European origin were present in the Yucatecan feral population in frequencies that indicate a process of European/African hybridization. These data suggest that population size, environmental conditions and characteristics of the established feral population in Yucatan have provided quantitative and qualitative opportunities for European gene introgression in the feral population, and thus better explain the present genetic composition of feral Africanized honeybees in southeast Mexico.

Six enzyme systems were studied to determine the genetic variability in honeybee populations in Turkey. Ten morphometric characters were also measured to determine the extent of morphometric variation. Out of six enzyme systems, four were found to be polymorphic with 16 allozymes. The average heterozygosity was calculated as 0.072+-0.007. Morphometric and electrophoretic variables were equally effective in discriminating honeybee populations. European and Anatolian honeybees were separated on the first axis, and Anatolian honeybees were further separated along a second canonical axis. The observation of rare alleles in isoenzymes, detection of high genetic diversity and the presence of four known subspecies support the argument that Anatolia has been a genetic center for honeybee populations in the Near East.

Newly-emerged honey bees were placed in cages and fed sucrose syrup and one of the following single-pollen diets: Malus domestica Borkh., Brassica campestris L., Phacelia tanacetifolia L., Melilotus officinalis (L.) Pall., Helianthus annuus L., Pinus banksiana (Lamb.), artificial supplement (Bee-Pro(R)) or nothing. Hypopharyngeal gland protein was determined at intervals of 0, 3, 8 and 14 days and ovary development was visually scored on day 14. The development of hypopharyngeal glands and ovaries varied with diet and, collectively, proved to be sensitive measures of protein utilization and pollen quality. For workers fed 1-year -old Phacelia pollen, protein was utilized in a differential fashion, promoting the development of ovaries over that of hypopharyngeal glands. Development of glands and ovaries was strongly correlated with the amount of protein workers consumed from pollen diets, and to a lesser extent, the crude protein content of diets. Storing pollen for 1 year by freezing did not affect gland or ovary development.

Techniques to effectively store honey bee semen must meet some minimally acceptable level of spermatozoa survival. To determine this level, honey bee queens were inseminated using various mixes of fresh and freeze-killed semen, and were allowed to lay eggs in small colonies for three weeks. The queens receiving all freeze-killed spermatozoa (0% fresh) had no spermatozoa in their spermathecae, and produced only drone pupae (unfertilized eggs). The proportions of live and dead spermatozoa (determined by dual fluorescent staining) in the spermathecae of queens receiving 25 to 100% fresh semen were not significantly different at 27 days post-insemination. Queens receiving 50% fresh semen or more produced only worker pupae (all eggs were fertilized). Therefore, a program to improve storage of semen should only have to reach survival levels of 50% of the spermatozoa to have functional semen.

The European honey bee (Apis mellifera) has the unusual status of being an inherently wild species from which a natural foodstuff (honey) is derived by manipulating its behaviour to deposit this in man-made wooden frames. Bees also produce propolis and Royal Jelly which can be harvested but their most important effect is one not immediately obvious as an economic product: that of pollination. Bee diseases are predominantly infectious and parasitic conditions accentuated by the close confinement in which they congregate, either in man-made hives or in colonies in a natural cavity. Treatment or at least control of some of these conditions can be attempted. In some cases natural bee behavioural traits limit the effect of the disease while in others, such as the notifiable disease American foulbrood, destruction of the colony is the only method of control. The mite Varroa jacobsoni can be controlled by the synthetic pyrethroids flumethrin and tau-fluvalinate. The introduction of these products has heightened veterinary interest in this important invertebrate species.

Honey samples from Apis dorsata, A. cerana and A. mellifera were collected by cutting a piece of honey comb directly from the colonies on the same day and from the same floristic region of Chitwan district, central Nepal. Physico-chemical analysis of the honey samples was performed. The values obtained for moisture content, electrical conductivity (EC), invertase, and proline content were significantly different between all the honey groups. The analytical values for Apis dorsata (n = 28), A. cerana (n = 26), and A. mellifera (n = 27) respectively were: 21.5, 20.1 and 17.1 moisture content (g/100 g honey); 0.96, 0.65 and 0.31 EC (mS/cm), 373.4, 218.2 and 110.9 invertase (Siegenthaler U/kg), and 875.8, 323.0 and 610.2 proline (mg/kg). There were no significant differences between the honey types in pH, glucose oxidase, and the amount of glucose. However, the amount of fructose was significantly higher in A. dorsata and A. cerana than in A. mellifera honeys. Similarly, the amount of oligosaccharide L2 was significantly higher and sucrose was significantly lower in A. dorsata honeys than in A. cerana and A. mellifera honeys.

In spite of Erythrina species exhibit morphologic attributes for adaptation to pollination by nectarivorous birds mentioned in the literature, E. speciosa is pollinated by lots of bees (Apinae and Meliponinae) which show a great urban occurrence. Systems of E. speciosa floral reproduction, fenology, diversity, frequency and constancy of insects visiting at different hours and flowering periods were studied. E. speciosa is autocompatible, but xenogamy is the predominant system of reproduction. A large diversity of insects visiting the inflorescences was observed, with predominance of bees. The bee species showed a higher frequency: Apis mellifera Linnaeus, 1758 (45,0 %), Trigona spinipes (Fabricius, 1793) (28,6%), Trigona hyalinata (Lepeletier, 1836) (12,2 %) and the ant Zacryptocerus pusillus Klug, 1824 (2,8 %). Constant but not frequent were the bees (Apidae) Plebeia droryana (Friese, 1900), Friesella schrottkyi (Friese, 1900), Nannotrigona testaceicornis (Lepeletier, 1836), Tetragonisca angustula (Latreille, 1811), the wasps (Vespidae) Polybia paulista Ihering, 1896, Protopolybia exigua (de Saussure, 1854), Agelaia pallipes (Olivier, 1791), the ant (Formicidae) Pseudomyrmex sp. and the beetle (Chrysomelidae) Diabrotica speciosa (Germar, 1824). E. speciosa flowers were visited by hummingbirds (Trochilidae): Eupetomena macroura (Gmelin, 1788), Clorostilbon aureoventris (d'Orbigny AMPERSAND Lafresnaye, 1838) and Amazilia sp. The birds Passer domesticus (Linnaeus, 1758) (Ploceidae) and Coereba flaveola (Linnaeus, 1758) (Emberizidae), also are present. The frequency and insect distribution were influenced by ambiental factors. Temperature, light, time, barometric pressure, relative humidity and wind velocity were significantly correlated with insect numbers. There is a visit sequence, by floral resource disponibility during the day, conditioned by transport ability, insect numbers and colony necessity, which begins by A. mellifera followed by meliponid bees. These bees make the pollination when they collect the pollen. There is a great animal variety which are sustained by flowers. It is suggested that E. speciosa is one important food source for urban fauna in winter, and so it should be utilized more frequently in streets, parks and gardens arborization.

The effects of high or low pollen storage on Apis mellifera L. brood removal behavior and Varroa jacobsoni reproduction were examined. High pollen storage colonies removed 49% of the infested larvae compared to 33% removal by the low pollen storage colonies. No difference was found in the proportion of fertile mites between those reared in high or low pollen storage colonies, although mite fertility appeared to decrease from mid to late summer in British Columbia, Canada. These findings indicate that the presence of pollen stores increases the rate of cell removal, and warrants further investigation into colony management as a potential means of V. jacobsoni infestation control.

This paper analyzes the summer and winter total protein content of 7, 14, 21, 28, 35, and 40-day old Apis mellifera L. worker venom glands before (control) and 24 and 96 hours after applying electrical shocks for venom extraction (experimental). During venom extraction, 7-day old workers responded more slowly and weakly to electrical shocks. This response intensifies with age, so that the workers approaching 20 days old respond faster and more aggressively to the shocks. Statistical analysis, using the non-parametric Wilcoxon and Kruskall-Wallis tests and complemented by the Jonckheere test, showed that the protein content varied from one age to another in the experimental group, which was well distinguishable from the values in the control Group in summer and winter. Summer values at all ages were always higher than those detected in winter in both groups. This variation seems to indicate the occurrence of more than one winter glandular development cycle. Histological studies showed secretion in the lumen of the control Group secretory tubes and reservoirs. The experimental group only showed vestigial secretion in the collapsed reservoirs at all ages, except at 7 days. These workers, which reacted less efficiently to electrical shocks, showed secretion in the lumen, reservoir, and tubes, even after the application of electrical shocks. During the 96 hours following the electrical shocks, a slight protein replacement was seen at some ages. This, although higher in summer than in winter, was much lower than the level detected in the control group at all ages. The significantly lower values were frequent in the older workers 96 hours after extraction and could reflect reabsorption or degradation of proteins from glandular secretion due to aging. Our results show that venom extraction is more productive in summer using older workers. However, their capacity of replacing protein eliminated during stinging of the substrate, in response to shocks is shown to be low, as demonstrated for other analyzed bees.

Nestmate recognition is essential for maintaining colony integrity in social insects. To discriminate between nestmates and non-nestmates, social insects use self-produced and environmentally-acquired recognition cues. In honey bees, both types of recognition cues have been implicated. We investigated the effect that floral oils (anethole, citronellal, limonene and linalool) have on the probability of nestmates and non -nestmates being accepted by guard bees at nest entrances. Floral oils did not affect the probability of workers, either nestmates or non-nestmates, being accepted by guards. However, the presence of floral oils did increase the time taken for a guard to reject an introduced bee. These data show that guards are sensitive to floral oils, but use other recognition cues when assessing colony affiliation.

Honey bees (Apis mellifera carnica, Apidae, Hymenoptera) visited a pond in order to collect water. During their stays at the pond the body surface temperature of water foragers was measured using contactless thermography. Irrespective of the ambient temperature (TA) which ranged from 13.6 to 27.2degreeC, the water carriers reached thoracic temperatures of 36 -38.8degreeC (mean values of the measuring periods). The maximum thoracic value of an individual bee was 44.5degreeC. At higher TA (20.9 -27.2degreeC) head and abdomen were only about 3degreeC and 2degreeC on the average higher than the surroundings, respectively. In the lower range of TA (13.6-16.6degreeC), however, the bees warmed their heads up to 29.2degreeC (13degreeC above TA) and the abdomen up to 23.3degreeC (7.1degreeC above TA; mean values of the measuring periods). The head and abdomen were even provided independently of one another with heat from the thorax. At a higher TA only little heat came from the heated thorax into the abdomen, at a cooler TA (13.6-16.6degreeC) more heat reached the abdomen. In all probability, at a higher TA only a small amount of haemolymph was pumped from the thorax into the abdomen; the most warm blood probably circulated in the head-thorax area. The average duration of stays at the pond decreased linearly from 110 to 42 s with rising TA. Head and thorax showed great fluctuations of temperature. For example, the head was heated by 4.6degreeC within 25 s, the thorax by 6.1degreeC within 30 s. Foragers drinking sucrose solution are known to increase their thoracic temperature with rising concentration of the sucrose solution. The water foragers had thoracic temperatures similar to that of bees feeding on 0.5 molar sucrose solution. It is hypothesized that the foraging motivation of both groups was similar and therefore they regulated their thoraces at the same temperature level.

The three-dimensional structure of the 56 residue polypeptide Apis mellifera chymotrypsin/cathepsin G inhibitor 1 (AMCI-1) isolated from honey bee hemolymph was calculated based on 730 experimental NMR restraints. It consists of two approximately perpendicular beta-sheets, several turns, and a long exposed loop that includes the protease binding site. The lack of extensive secondary structure features or hydrophobic core is compensated by the presence of five disulfide bridges that stabilize both the protein scaffold and the binding loop segment. A detailed analysis of the protease binding loop conformation reveals that it is similar to those found in other canonical serine protease inhibitors. The AMCI-1 structure exhibits a common fold with a novel family of inhibitors from the intestinal parasitic worm Ascaris suum. The pH-induced conformational changes in the binding loop region observed in the Ascaris inhibitor ATI are absent in AMCI-1. Similar binding site sequences and structures strongly suggest that the lack of the conformational change can be attributed to a Glu fwdarw Gln substitution at the P1' position in AMCI-1, compared to ATI. Analysis of amide proton temperature coefficients shows very good correlation with the presence of hydrogen bond donors in the calculated AMCI-1 structure.

Some properties of a Africanized honeybee venom proteases were determined by enzymatic assays in solution, electrophoresis in SDS-PAGE, and gel filtration. Bee venom extracts were obtained by reservoir disruption, selective dialysis (cut off 12 kDa) to eliminate small components, such as the protease inhibitor present in the venom, and then fractionation of the dialyzed extract by gel filtration on a Sephadex G-100 column. The optimal conditions for the caseinolytic assays were pH 9.5, 2-hour digestion at 37degree C, and 1% casein concentration. The proteolytic activity was also determined by electrophoresis in SDS-PAGE with co-polymerized gelatin with three major bands of 66.0, 41.6, and 25.1 kDa. A principal serine-protease -like mechanism was revealed in the enriched fraction of proteolytic activity.

Antennal movements of the honey bee can be conditioned operantly under laboratory conditions. Using this behavioural paradigm we have developed a preparation in which the activity of a single antennal muscle has been operantly conditioned. This muscle, the fast flagellum flexor muscle, is innervated by an identified motoneuron whose action potentials correlate 1:1 with the muscle potentials. The activity of the fast flagellum flexor muscle was recorded extracellularly from the scapus of the antenna. The animal was rewarded with a drop of sucrose solution whenever the muscle activity exceeded a defined reward threshold. The reward threshold was one standard deviation above the mean spontaneous frequency prior to conditioning. After ten conditioning trials, the frequency of the muscle potentials had increased significantly compared to the spontaneous frequency. The conditioned changes of frequency were observed for 30 min after conditioning. No significant changes of the frequency were found in the yoke control group. The firing pattern of the muscle potentials did not change significantly after conditioning or feeding. Fixing the antennal joints reduces or abolishes associative operant conditioning. The conditioned changes of the frequency of muscle potentials in the freely moving antenna are directly comparable to the behavioural changes during operant conditioning.

Forager bees arriving at the hive after visiting a nectar source, unload the collected liquid food to recipient hivemates through mouth-to-mouth contact (trophallaxis). We analysed whether the main characteristics that define nectar in energetic terms, that is, rate of production (flow of solution), sucrose concentration and rate of sucrose production (sucrose flow) influence trophallactic behaviour. Individual bees trained to feed at a regulated-flow feeder offering sucrose solution were captured once the foraging visit was complete and placed in an acrylic arena with a recipient bee that had not been fed. The rate at which liquid was transferred during the subsequent trophallactic contact (transfer rate) was analysed as a function of the different solution flows and sucrose concentrations offered at the feeder. A relationship was found between transfer rate during trophallaxis and the flow of solution previously presented at the feeder. This relationship was independent of sucrose concentration when above a certain threshold value (ca. 22% weight on weight). We also analysed whether the rate of sucrose deliverance of the food source (sucrose flow) influenced the rate at which the solution was transferred. No clear relationship was found between the rate of sucrose deliverance during trophallactic events (sucrose transfer rate) and the sucrose flow presented at the feeder. The possibility that trophallaxis could be a communication channel through which quantitative information on food source profitability is transmitted among hivemates is discussed.

The araca-boi (Eugenia stipitata Mc Vaugh ssp. sororia Mc Vaugh, Myrtaceae) is a small fruit species native to western Amazonia with international potential as a juice and flavor. Although seldom planted in Brazilian Amazonia because of its acidity, the species is being cultivated in other countries. A knowledge of phenology can help plan plantation management and fruit commercialization. The phenology of ten plants growing in a degraded oxisol was observed during five years. The araca-boi generally flowered and fruited three times during the year, with at least one strong flowering peak in the dry season (July-September) and a strong fruiting peak in the rainy season (January-March). Flower initiation is a complex event that appears to take two to three months, although the period from flower bud appearance to anthesis is short (apprx15 days) and the period from anthesis to fruit maturation takes between 50 and 60 days. The multiple regressions used to determine the effect of climatic variables on flowering and fruiting had low determination coefficients, although the models were significant, probably because the araca-boi flowers several times during the year and the most important stimulous for flowering is still unknown. Fruit set varied from less than 5% to about 15%. Mean fruit weight in January 1988 was 135 g, with 77% of pulp. During the 5 years, the 10 plants yielded 1000 fruits/year, with a median number of 890 fruits/year. Most of the insect visitors were bees, especially Apis mellifera, Eulaema mocsaryi and Ptilotrigona lurida.

The aim of this preliminary experiment was to evaluate the effect of distance from the apiary on pod yield in canola. Beehives were used at a density of 1.28 hives/ha. The results showed that the number of pods/plant decreased as distance from the apiary increased, when plant height and branch number were used as explanatory variables. Multiple linear regression indicated a predicted pod loss of 15.3 pods/plant over a distance of 1000 m from an apiary. This was equivalent to a 16% loss based on an average of 59 plants/m2 and average pod production of 5666 pods/m2 from his experiment. For a 2 t/ha crop this would be equivalent to about 320 kg/ha. The results are only indicative because of the variation in the crop studied and lack of replication, but may, in fact, be a conservative estimate.

The genetic variability of honeybee populations Apis mellifera ligustica, in continental Italy, and of A. m. sicula, in Sicily, was investigated using nuclear (microsatellite) and mitochondrial markers. Six populations (236 individual bees) and 17 populations (664 colonies) were, respectively, analysed using eight microsatellite loci and DraI restriction fragment length polymorphism (RFLP) of the cytochrome oxidase I (COI)-cytochrome oxidase II (COII) region. Microsatellite loci globally confirmed the southeastern European heritage of both subspecies (evolutionary branch C). However, A. m. ligustica mitochondrial DNA (mtDNA) appeared to be a composite of the two European (M and C) lineages over most of the Italian peninsula, and only mitotypes from the African (A) lineage were found in A. m. sicula samples. This demonstrates a hybrid origin for both subspecies. For A. m. ligustica, the most widely exported subspecies, this hybrid origin has long been obscured by the fact that in the main area of queen production (from which most of the previous ligustica bee samples originated) the M mitochondrial lineage is absent, whereas it is present almost everywhere else in Italy. This presents a new view of the evolutionary history of European honeybees. For instance, the Iberian peninsula was considered as the unique refuge for the M branch during the quaternary ice periods. Our results show that the Apennine peninsula played a similar role. The differential distribution of nuclear and mitochondrial markers observed in Italy seems to be a general feature of introgressed honeybee populations. Presumably, it stems from the social nature of the species in which both genome compartments are differentially affected by the two (individual and colonial) reproduction levels.

A model of simple algorithmic "agents" acting in a discrete temperature field is used to investigate the movement of individuals in thermoregulating honey bee (Apis mellifera) clusters. Thermoregulation in over-wintering clusters is thought to be the result of individual bees attempting to regulate their own body temperatures. At ambient temperatures above 0degreeC, a clustering bee will move relative to its neighbours so as to put its local temperature within, some ideal range. The proposed model incorporates this behaviour into an algorithm for bee agents moving on a two-dimensional lattice. Heat transport on the lattice is modelled by a discrete diffusion process. Computer simulation of this model demonstrates qualitative behaviour which agrees with that of real honey bee clusters. In particular, we observe the formation of both disc- and ring-like cluster shapes. The simulation also suggests that at lower ambient temperatures, clusters do not always have a stable shape but can oscillate between insulating rings of different sizes and densities.

The influence of colony pollen storage and pupal infestation by the parasitic mite Varroa jacobsoni on worker longevity, foraging age, and behavior were investigated in the honey bee, Apis mellifera L. Workers reared in colonies with low pollen stores began foraging at younger ages and may have had shorter lifespans than workers reared in colonies with high pollen availability. Similarly, workers began foraging at younger ages and had shorter lifespans when they had been infested by V. jacobsoni as pupae. The decrease in foraging age and possibly lifespan caused by the pupal infestation was offset by the colony's pollen environment during brood rearing. Therefore, temporal task schedules are affected by both colony investment and parasitism by V. jacobsoni during brood rearing.

The onset of foraging, proportion of pollen collectors, and weight of pollen loads were compared in individual honey bees (Apis mellifera) infested by zero, one (Acarapis woodi, the honey bee tracheal mite, or Varroa jacobsoni, varroa), or both species of parasitic mites. Phoretic varroa host choice also was compared between bees with and without tracheal mites, and tracheal mite infestation of hosts was compared between bees parasitized or not by varroa during development. The proportion of pollen collectors was not significantly different between treatments, but bees parasitized by both mites had significantly smaller pollen loads than uninfested bees. Mean onset of foraging was earliest for bees parasitized by varroa during development, 15.9 days. Bees with tracheal mites began foraging latest, at 20.5 days, and foraging ages were intermediate in bees with no mites and both, 17.6 and 18.0 days respectively. Phoretic varroa were found equally on bees with and without tracheal mite infestations, but bees parasitized by varroa during development were almost twice as likely to have tracheal mite infestations as bees with no varroa parasitism, 63.9% and 35.5%, respectively. These results indicate that these two parasites can have a biological interaction at the level of individual bees that is detrimental to their host colonies.

The visual discrimination of horizontal gratings by the honeybee (Apis mellifera) was studied in a Y-choice apparatus with fixed patterns presented vertically at a set range. Translocation in this context is the exchange of the positions of two different colored or black areas. This paper investigates what cues the bees have learned in this task. The patterns, made from combinations of calibrated colored papers, are designed to explore the parts played by the blue and green receptors when the boundary between the two colors provides contrast to only one receptor type. Horizontal translocation is not discriminated without contrast to the green receptors, but up/down translocation can be discriminated whatever the contrast at the boundary. The trained bees were tested on the same patterns made with different papers that included extreme changes in contrast. The results show that discrimination of up/down translocation involves green receptors and also blue receptors. When bees discriminate a translocation that shows contrast to only one type of receptor, they do not use the apparent brightness or the direction of the contrast to that receptor type acting alone. Instead, they discriminate the locations of colored areas irrespective of intensity differences or directions of contrasts. They use some measure of the photon flux at both receptor types and remember the difference between the colors and their locations.

Previous research showed that age-related division of labor in honey bees is associated with changes in activity rhythms; young adult bees perform hive tasks with no daily rhythms, whereas older bees forage with strong daily rhythms. We report that this division of labor is also associated with differences in both circadian rhythms and mRNA levels of period, a gene well known for its role in circadian rhythms. The level of period mRNA in the brain oscillated in bees of all ages, but was significantly higher at all times in foragers. Elevated period mRNA levels cannot be attributed exclusively to aging, because bees induced to forage precociously because of a change in social environment had levels similar to normal age foragers. These results extend the regulation of a "clock gene" to a social context and suggest that there are connections at the molecular level between division of labor and chronobiology in social insects.

The introduction of the African bees (Apis mellifera scutelata) in Brazil and their expansion in the American Continent created the opportunity to study the process of species adaptation in a new environment. In that process, within intra-specific variability, normalising selection can favour individuals that present a better adaptative morphology and they will constitute the most frequent type found in the population. To test that hypothesis morphometric analyses in samples of colonies of africanized bees and in samples of the populations were performed. The development of the colonies was also evaluated in terms of the amount of their brood, honey and pollen. Analysis of the data indicates that more developed colonies are formed by individuals closer to the population average with concerning morphological traits.

The effectiveness of using honey bees and bumble bees to vector a commercial formulation of Trichoderma harzianum 1295-22 for the control of Botrytis cinerea on strawberries was evaluated from 1994 to 1997 in 2 strawberry fields at the New York State Agricultural Experiment Station in Geneva, New York and in 10 grower fields in eight counties of New York. Commercial bumble bee colonies were used to deliver the biocontrol agent in 1994 and 1995 and five-frame nuclear honey bee hives were used in 1995 -1997. Each honey bee exiting the hive carried about 1 X 105 colony -forming units of T. harzianum, with the majority found on the bees' legs (58%). Flowers collected from the bee-delivered treatment generally had half the density of T. harzianum as those from the sprayed treatment. However, during the 4 years of this study, T. harzianum delivered by bumble bees or honey bees provided better Botrytis control than that applied as a spray. In addition, the bee-delivered T. harzianum provided the same or a better level of control of Botrytis as commercial fungicides applied at bloom. Strawberries collected from the bee-visited treatments averaged 22% more seeds and weighed between 26 and 40% more than berries in nonvisited treatments. The number of seeds per berry and berry weight were reduced by 7-12% in plots treated with fungicides and visited by bees, indicating that the use of some commercial fungicides at bloom may impact pollination and yield. Bee delivery of T. harzianum 1295-22 is a viable option for strawberry growers interested in controlling Botrytis with minimal fungicide use.

Eleven samples of honey from the region of Loukkos (provinces of Asilah, Larache and Ksar el Kebir) are analysed. The samples were directly provided by professional honeys producers. A total of 60 taxa have been identified. Results show that nectar is the main source for honey in this territory and that two samples belong to class V of Maurizio, four to class III, one to class II and four to class I. Three of the honey samples are monofloral; one of them is formed mainly by Ammi visnaga and the other two by orange (Citrus siensis).

Pollinator activity, flowering phenology, plant size, and seed set of an endangered annual plant, Pogogyne abramsii, were compared in natural and created vernal pools on Del Mar Mesa, San Diego County, California, USA. The purpose was to test the hypothesis that an artificial habitat would have fewer or less effective pollinator visits than natural vernal pools and that, as a result, the plants would have lower fecundity. The effect of differences in flowering phenology and plant size among pool types on pollinator visitation and seed set was also evaluated. The most frequent insect visitors to P. abramsii flowers were the Eurasian honey bee, Apis mellifera, two anthophorid bees, Exomalopsis nitens and E. torticornis, and three species of bee flies, of which Bombylius facialis was by far the most abundant. All species of insect visitors displayed density-dependent foraging on P. abramsii, with greater numbers of visits per unit area where flower density was greater. Nevertheless, visits per flower were negatively correlated with flower density. Flowering phenology of P. abramsii was delayed in most created compared to natural vernal pools, which affected the frequency by species of insect visitors to created compared with natural vernal pools. Peak flower densities were significantly lower in created than in natural vernal pools. The created pools had more visits per flower. Plants were smaller in created pools compared to natural pools, and seed production was positively correlated to plant size. Seed set in P. abramsii was greater than one per plant in both created and natural pools but was significantly lower in created vernal pools. Most of this difference could be attributed to the larger size of plants in the natural pools. We conclude that pollinator limitation should not preclude the sparser populations of smaller plants in the created pools from having a positive growth rate. Subsequent establishment and persistence of populations in a majority of created basins on this site confirms this assertion.

Imidacloprid (1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2 -ylideneamine) belongs to a new chemical family of chloronicotinyl compounds whose mode of action on the insect nervous system differs from that of traditional neurotoxic products. Imidacloprid, a strong systemic compound, is effective against several sucking and mining pests. The acute toxicity of contact and oral applications on two Apis mellifera subspecies, Apis mellifera mellifera and Apis mellifera caucasica, was investigated. In all toxicological studies, each dose included three cages of 20 individuals and each study was replicated three times. The dose -mortality relation revealed some unusual characteristics. At low imidacloprid concentrations, a biphasic mortality appeared, particularly with the contact exposure route. At moderate doses, mortality profiles at 24 and 48 h were different only after oral application. Response kinetics showed that mortality was delayed at the higher doses of imidacloprid. After oral intoxication, the LD50 values of imidacloprid at 24 and 48 h were about 5 ng/bee for both A. m. mellifera and A. m. caucasica. After contact application, the LD50 values at 24 and 48 h were approximately 24 ng/bee for A. m. mellifera and 14 ng/bee for A. m. caucasica. Imidacloprid ranks among the more potent contact insecticides in this important pollinator species.

Photoreceptor cells of the honeybee drone fire, in the presence of the polycationic aminoglycoside neomycin, repetitive slow spike-like potentials superimposed on the receptor potential plateau phase. We have used conventional intracellular recordings and microfluorometric intracellular Ca2+ measurements to characterize these spike potentials. We have shown that the spike frequency increases in a light-intensity -dependent manner. The spikes are fired only when light stimuli depolarize the cell from a resting potential of -50 to -60 mV to at least -40 to -45 mV; they are tetrodotoxin insensitive and blocked by the Ca2+ channel blockers Ni2+, Cd2+, omega-agatoxin TK, verapamil and methoxyverapamil. Depolarization of the photoreceptors with high extracellular K+ in the presence of neomycin in darkness does not generate spikes. Small intracellular Ca2+ oscillations superimposed on the plateau phase of the light-induced increase in intracellular free Ca2+ concentration have a similar temporal pattern as the spike-like potentials. We conclude that the spike-like potentials require stimulation by light and are generated by voltage-dependent Ca2+ channels localized on the soma of the photoreceptors, distal to the basal lamina.

Experiments to study the ability of adults (workers and drones) of the eastern honey bee, Apis cerana indica Fabr., and the western honey bee, Apis rnellifera L., to uncap brood cells were undertaken in Bangalore, India. Using halved gelatin capsules, individual adults were confined opposite the intact cap that sealed vacant, isolated brood cells. From inside the cell, workers and drones of both species penetrated the drone -cell cap of A. mellifera with regularity. When placed outside the cell, workers of both species were successful in perforating the same cap. Similarly, A. c. indica workers easily perforated the cap of A. c. indica worker cells from inside. However, significant caste-specific differences in success at perforating the cap of A. c. indica drone cells were observed; whereas drones did so regularly, A. c. indica workers usually perished when so challenged. When held facing the cap while inside or outside the drone cell, none or only 10% of workers, respectively, managed to chew a hole in it. Even when two workers faced the same drone-cell cap, one from each side, only 20% of caps were perforated. These results are consistent with the hypothesis that the tough apex of the drone cocoon of A. cerana is typically impervious to uncapping from outside, and hence has provided an opportunity for the uninterrupted reproduction of invading parasitic mites (Varroa spp.). The mandibles of drones of both species possess a diminutive apical tooth along the distal margins that is absent in workers. The lack of mandibular teeth in workers may explaln the disparity in ability to penetrate the tough cocoon of A. c. indica drones. The mandibles of both castes suffer wear.

We investigated the ability of honeybees, Apis mellifera, to use olfactory information gained in a given experimental context, in other contexts. First, restrained bees were subjected to a Pavlovian associative learning procedure, based on the conditioning of the proboscis extension response (PER), where a floral odour was paired with a sugar reward. We observed the orientation behaviour of conditioned and naive bees in a four-armed olfactometer with four contiguous fields either scented with the conditioning odour or unscented. Information transfer was clearly shown, conditioned bees orienting towards the conditioning odour, whilst naive bees shunned it. Second, the effect of passive olfactory exposures during the bees' development was assessed in two behavioural contexts: either orientation in the olfactometer or a PER conditioning procedure. Two exposure periods were applied: (1) the pupal stage (9 days before emergence); (2) the early adult stage (8 days after emergence). No effect of preimaginal exposure was recorded, but exposure during the early adult stage induced a higher choice frequency of the odour field in the olfactometer, and lower learning performance in the PER conditioning assay. These observations show that olfactory information gained during development can modify bees' later behaviour in different contexts: this is another instance of olfactory information transfer in bees. These results also suggest that nonassociative learning phenomena, taking place at a critical period during development, might be involved in the maturation of the bees' olfactory system, and in the organization of odour -mediated behaviours.

The pollination ecology of Swartzia apetala Raddi var. apetala was studied in the restinga of Marica, State of Rio de Janeiro, Brazil. S. apetala var. apetala is a shrub with asynchronic annual blooming, between the months of November and April (hot-rainy season). Each plant can exhibit more than one blooming episode in this period. Their flowers are hermaphrodites, apetalous, heterantherous, odoriferous, and the pollen represents the only reward offered to visitors. It is pollinized by species of Centris and Xylocopa, solitary and polyletic bees, which collect the pollen by means of vibratory movements. Other bees such as Apis mellifera, Pseudaugochloropsis graminea and Trigona spinipes are only pollen-thieves. In this variety of Swartzia vibrating is an efficient method to collect pollen from the anthers despite non-poricidal dehiscence.. The flowering phenology and the behavior of visitors influence the rate of outcrossing.

Globe artichoke is currently multiplied mainly by vegetative means, but the planting of seeds could lead to easier cropping practices and improved yields. This is especially true with hybrid seeds which could be produced using the two genetic male-sterility systems available. For two years, we studied the effectiveness of honey bees as pollinators to produce hybrid seeds of globe artichoke under insect-proof enclosures. We used two adjacent 10 X 6 m tunels covered with 1-mm mesh screen and planted with 2 male-fertile (MF) and 7 male-sterile (MS) lines. Each tunnel was provided with a colony of 3,500 bees at the onset of MF flowering. Flowering of MS and MF lines was well synchronized, and the number of flower heads per plant was similar for all lines. Yet, there were over 10-fold differences in both years in the density of foragers that visited the various lines with extremes of 0.04 to 1.18 honey bees per head. Some foragers collected pollen, but these were rarely seen on MS heads. The ranking of MS lines in terms of forager density was similar over both seasons, which suggests that the differences in attractiveness among these lines were of genetic origin and probably resulted from differences in nectar availability or composition. Yield of achenes per plant also varied significantly among lines. The proportion of heads that were empty ranged from 23% to 100% among MS lines, and for each season was negatively correlated with the average forager density on each line. The number of achenes per head in the flower heads which were not empty did not vary significantly among MS lines, which suggests that the pollination effectiveness of honey bee visits was similar among these different lines. This achene content was greater in MF heads, which is consistent with a greater pollination effectiveness of honey bees in this inflorescence due to the presence of pollen and some self-fertility in MF lines. The overall forager density was similar between the two seasons as was the proportion of empty MS heads, but the achene content of non-empty MS heads was significantly greater in the second year than in the first one. This suggests that the pollination effectiveness of individual visits was greater in the second year. Pollen availability was similar in both seasons, but there were 5 times fewer foragers collecting pollen in the second year compared to the first one. The pool of pollen is limited when producing hybrid seed, especially in confined environments, and our results suggest that in these situations the level of pollen collection may negatively affect the pollination activity of honey bee colonies.

This experiment was carried out to study the internal temperature regulation of a colony of Africanized honey bees (AFR), compared with hybrid Caucasian (CAU), Italian (ITA), and Carniolan (CAR) bees, during the period of one year and different size hives located in a sub-tropical region. The instant internal temperature, 33.7 +- 1.5degreeC for the AFR, 33.5 +- 1.4degreeC for the CAU, 33.7 +- 1.5degreeC for the ITA and 33.8 +- 1.4degreeC for the CAR, did not show any significant difference (P RGT 0.05). The maximum temperature (36.1 +- 2.3degreeC) was statistically different (P LGT 0.05) from the minimum (27.6 +- 5.3degreeC). There was no difference (P RGT 0.05) in the mean internal temperature, between the nucleus (31.7 +- 6.3degreeC) and the brood nest (32.1 +- 5.3degreeC) measured between two and four o'clock in the afternoon.

Latent inhibition (LI) in honeybees (Apis mellifera) was studied by using a proboscis extension response conditioning procedure. Individual queens, drones, and workers differed in the degree to which they revealed LI. The authors hypothesized that individual differences would have a substantial genetic basis. Two sets of progeny were established by crossing virgin queens and individual drones, both of which had been selected for differential expression of inhibition. LI was stronger in the progeny from the queens and drones that had shown greater inhibition. The expression of LI was also dependent on environmental factors that are most likely associated with age, foraging experience outside of the colony, or both. Furthermore, there was a correlated response in the speed at which progeny reversed a learned discrimination of 2 odors. These genetic analyses may reveal underlying mechanisms that these 2 learning paradigms have in common.

Free-flying honeybees (Apis mellifera) were trained in a series of experiments designed to look for evidence of risk sensitivity in foraging for sucrose solution. The suitability of the choice method used was established in 3 preliminary experiments with differences in concentration, amount, and probability of reward. Of 5 subsequent experiments in which 2 alternatives provided the same mean concentration of sucrose solution with different variance, 3 showed risk indifference, and 2 showed risk aversion (preference for consistent reward). Of 2 final experiments in which the alternatives provided the same mean amount of sucrose solution with different variance, both showed risk aversion. Performance could be simulated quantitatively with a simple choice model developed by P. A. Couvillon and M. E. Bitterman (1991) to account for the results of a wide range of previous experiments on discriminative learning in honeybees.

The variability in the mitochondrial DNA of honeybees (Apis mellifera iberica) has been studied sampling thirty-six fixed hives from eight localities of Murcia (Southeastern Spain). The intergenic region between tRNAleu and cytochrome-oxidase II genes has been amplified by PCR and digested with the restriction enzyme Dra I. The amplified fragments have also been sequenced. A high percentage (97.22%) of the samples belongs to the African lineage of subspecies and races that predominates in Southeastern Spain. Digestion with Dra I shows that there are the haplotypes A2 (86.11%) and A1 (11.11%) of lineage A, whereas there is only one sample belonging to the lineage C of bees coming from Eastern Europe (which includes Apis mellifera ligustica). The hives are markedly homogeneous and do not show introgression from close hives in which importation of Italian queens is known; the variability was supposed to be higher because of annual changes of locality belonging to different Spanish regions. A lower adaptation of foreign queens to local conditions and a low rate of queen importation are discussed as possible explanations to these results.

For a artificial wing driven by a mechanism of indirect wing movement known as "constant wing oscillation and efficiency", basic mechanical studies were performed. Two approaches, 1) mathematical and mechanical modeling and 2) FEM analysis, were employed. Two elastic constants, used as the wing and integument oscillation, were obtained.

The neotropical wasp Agelaia pallipes pallipes is aggressive and endemic in southeast of Brazil, where very often it causes stinging accidents in rural areas. By using gel filtration on Sephadex G-100, followed by high performance reversed phase chromatography in a C-18 column under acetonitrile/water gradient, the agelotoxin was purified: a toxin presenting phospholipase A2 (PLA2) activity, which occurs under equilibrium of three different aggregation states: monomer (mol. wt 14 kDa), trimer (mol. wt 42 kDa) and pentamer (mol. wt 74 kDa). The enzyme presents high sugar contents attached to the protein chain (22% (w/w)) and a transition of the values of pH optimum for the substrate hydrolysis from 7.5 to 9.0, under aggregation from monomer to pentamer. All the aggregation states present Michaelian steady-state kinetic behavior and the monomer polymerization caused a decreasing of phospholipasic activity due a non-competitive inhibition promoted by the formation of a quaternary structure. The PLA2 catalytic activity of agelotoxin changes according to its state of aggregation (from 833 to 12533 mumol mg-1 min-1) and both the monomeric and oligomeric forms present lowest activities than the PLA2 from Apis mellifera venom and hornetin from Vespa basalis. Agelotoxin is also a very potent direct hemolysin; the monomer of agelotoxin presented hemolytic actions until 200 times higher than the PbTx from P. paulista, 740 times higher than the PLA2 from A. mellifera, 570 times higher than that of neutral PLA2 from N. nigricolis and about 1250 times than that of cardiotoxin from Naja naja atra venom.

Thirty-nine samples of Apis mellifera monticola and A. m. scutellata from three different regions of Kenya were analyzed for mitochondrial DNA (mtDNA) variation using 6-base and 4-base restriction enzymes. Restriction with HpaII and AluI resulted in distinct patterns that together produced three different haplotypes. While haplotypes 2 and 3 were restricted to samples from the mountain forest, haplotype 1 was found in A. m. scutellata and in all samples from the Ngong Hills. No introgression of A. m. scutellata mtDNA was detected in bees collected in mountain environments, but a few samples from the savanna had A. m. monticola morphology, or mtDNA, or both. These results support the hypothesis that A. m. monticola is a distinct subspecies and not an ecotype of A. m. scutellata. The polymorphic restriction sites were mapped. Ten samples of A. m. litorea from the coast of Kenya were analyzed using polymerase chain reaction (PCR) amplification and subsequent restriction analysis. All samples of A. m. litorea shared the A. m. scutellata haplotype.

The ideas examined and the results presented in the last unfinished manuscript of Friedrich Ruttner have been further developed. Within the 6 populations of the Near East distinguishable by morphometry, the bees of Massandaran in Iran occupy an important position due to their large size. Even sea-level bees exceed the size of the bees of the elevated region of Central Iran, which seems to contradict Bergmann's rule. An extended study had revealed that this population, clearly belonging to the subspecies Apis mellifera meda, shows a very distinct size increase from the Caspian Sea to the northern slope of the Elbrus Mountains, rising to 2 200 m in elevation. A similar but less pronounced ecocline with a marked increase in size can be found reaching up from the Mediterranean coast to the elevated Central Iranian region. The general pattern within A. m. meda in the region along 36degree N latitude thus generally confirms Bergmann's rule, thus providing a fine example of an ecoclinal structure. However, size differences between the extremes, i.e., the Mediterranean and the coast of the Caspian Sea remain marked, which indicates an additional genetic component linked to a different history of the populations. This might prove to be an interesting aspect, as the area covered by A. meda is suspected to have played a major role in the evolution of A. mellifera.

We used the proboscis extension reflex of honeybees to test their ability to discriminate between comb waxes of different ages (wax scales, 1-week -old wax, 2- to 3-year-old wax, 8- to 10-year-old wax). Such waxes differ in their chemical composition, and an ability to discriminate between them may aid the orientation of the bees in the nest. To train the bees, we used whole extracts of waxes and four different fractions of the whole extract based on different elutions of solid-phase extractions (extract I, fraction A eluted with hexane and fraction B with diethylether; extract II, fraction B further subdivided into fraction C by elution with isopropylchloride and fraction D by elution with diethylether). In a differential training regime (six learning and six test trials) with whole extracts or with the different fractions, we paired one type of wax with a reward and another with no reward. The bees learned to discriminate between all tested pairs of whole extracts. The two subfractions (fractions A and B) gave different results: the bees could discriminate between waxes of different ages when fraction B was used but not when fraction A was used. A further subdivision of fraction B into fractions C and D showed that only fraction D contained the elements that enabled bees to discriminate between old and new wax. Fraction D makes up only 5-8 % of the total wax mass and contains hydroxy alkyl esters (5-6 % of the total wax mass), primary alcohols (0.3-0.5 % of the total wax mass) and acids (0.06-1.0 % of the total wax mass). Fractions A and C (together forming 62 -64 % of the total wax mass), which consist of unbranched and branched aliphatic hydrocarbons and alkyl esters, could not be discriminated by the bees. The remaining wax mass (25-29 %) was eluted with a mixture of chloroform, methanol and water (13:5:1) as fraction E.

In the 1960s, research on reproductive isolation in honeybees started with the pioneering work on Apis cerana and A. mellifera of F. Ruttner. Since then, the number of recognised Apis species increased from four to nine, and data on reproductive isolation played a key role in this development. In this paper, we discuss the behavioural mating barriers (mating season, mating place, sexual signals, daily mating periods), copulatory barriers (size, genitalia, mating sign) and physiological barriers (sperm transfer, sperm storage) and postzygotic barriers (fertilisation, development, hybrids). Allopatric A. mellifera and allopatric populations of the other species had a uniform mating period during the afternoon hours. Sympatric honeybee species were separated mainly by different daily mating periods. The mating period differed between populations of the same species from different regions. The sequence of the mating periods, however, described from Sri Lanka, Thailand and Sabah (Borneo) followed the same pattern and showed a taxonomic and size correlation: the dwarf bees (A. andreniformis and/or Apis florea) occupied the first position shortly after noon. The next mating period was occupied by cavity-dwelling bees and at sunset, A. dorsata drones flew out for mating. In addition, in the honeybee species that have been studied, various non behavioural mating barriers have been demonstrated.

Initial searches found little evidence of genotypic or phenotypic variance in the parasitic bee mite Varroa jacobsoni, despite numerous reports of significant variation in the mite's reproductive behaviour on its adopted host Apis mellifera. However, in a recent search that employed DNA sequencing techniques and large numbers of V. jacobsoni collected from the mites' native host A. cerana throughout Asia, a remarkable amount of genetic variation was observed. Subsequent analysis of this variation, coupled with follow-up morphological and ecology-based studies, showed that V. jacobsoni was a species complex. Other work carried out as part of that study also showed that only two out of 18 genetically different mites within the complex have switched host to A. mellifera and become a pest of this bee worldwide. These two mites are not V. jacobsoni as has been assumed, but they belong to a group of mites that naturally infest specific populations of A. cerana on mainland Asia. These mites will soon be renamed as a new species. This and other reports of variation in V. jacobsoni are reviewed and discussed.

Individually labeled freshly emerged honeybee workers (Apis mellifera) from three unrelated source colonies were introduced into five host colonies. The location of the workers during their first eight days of life was monitored. Workers from the same source colony tended to be found more often in the same area of the comb than workers from a different source colony. Although kin recognition among workers cannot be ruled out as a possible mechanism for this pattern, the results can be more readily explained by phenomena related to self-organized pattern formation, individual behavioral threshold variability and genetically determined worker task specialization.

The honeybees occurring along transects from low to high altitude were analysed for seven separate mountain systems in Africa using three suites of characters: morphometric characters, flight dimensional measurements and the mitochondrial DNA (mtDNA) restriction length fragments derived from the non-coding region of COI-COII by DraI restriction. Morphocluster definition was consistent with mtDNA cluster membership but not with flight dimensional data. When all three character suites are combined, six different kinds of unrelated mountain bees are obtained. The only commonality among the mountain bees is that they are larger than those of lower altitudes. Because of fundamental differences in the restriction length fragments and other clusters obtained, it is concluded that mountain bees should probably be regarded as ecotypically differentiated populations of the subspecies surrounding each particular mountain.

Population differentiation of African honeybees has been analysed in a spatial context encompassing the continent's wide geographical range and environmental heterogeneity, based on 10 morphological characters measured from 268 local populations. While autocorrelation indicates a continuous large-scale decrease in similarity in general, clustering of single character correlograms suggests four distinct groups of profiles. This pattern, further supported by mapping factor scores, canonical trend surface analysis axes scores, suggests a variety of microevolutionary mechanisms acting at distinct scales in time and space in different groups of characters. Association with large-scale differences in vegetation, climate and traditional subspecific classification has been analysed by analysis of variance (ANOVA). The most important aspect is that the results support the hypothesis that traditional subspecies, at least as defined by these characters, seem to represent integrated evolutionary units well adapted to their local conditions.

In order to predict Varroa jacobsoni Oud. population size, natural mite mortality and parasitic prevalence were compared. Positive correlation between death rate and mite population size was observed (r= 0.986). This close relationship is expresed by y = 10.123 X + 16.294 (p= 0.01; R2 = 0.9723). On the other hand, parasitic prevalence does not show a significative relationship with mite population size. Since the parasites have an aggregated condition, the honeybee colonies usually show a discontinuous distribution of mites depending on the examined zone. This uneven distribution would be causing a high level of error in sampling. Periodic monitoring of mite mortality, expressed as the number of mites collected from hive debris, could be a useful parameter to examine V. jacobsoni population growth. This is an easy method, harmless to the colonies and a suitable technique for the beekepeers.

The Varroa mite infestation level of honey bee, Apis mellifera, worker larvae reared in individual raised cells was 6-fold higher than in the adjacent six cells surrounding them; this differential infestation rate is similar to published values of higher mite infestations of drone cells compared to worker cells. Infestation levels in control cells were the same as in the surrounding cells. In contrast to infestation of these individually raised cells, Varroa mites invaded worker larvae in raised cells along the perimeter of a patch of raised cells (10 by 21 rows) 2.5 times more often than surrounding unraised cells, and similarly ca. 2.5 times more often than in the remaining raised cells (interior) of this patch. In similarly prepared frames of drone comb, Varroa mites invaded individually raised drone cells 3.3-fold more often than the adjacent surrounding cells and control cells. On the other hand, Varroa mites infested drone larvae in the interior of the raised-patch area as often as drones in raised cells along the perimeter of the raised-patch, and this rate was ca. 2.5-fold higher than for drone larvae in unraised cells surrounding the raised-patch and drone larvae in control cells. The higher levels of infestation of raised cells did not come at the expense of the surrounding cells, i.e., the infestation levels of the adjacent surrounding cells were the same as in control cells. For worker larvae, the increased number of mites invading individual raised cells and edge cells of the raised patch were proportional to the number of surrounding nonraised cells. The relationship between raised cell-edges, observations of mite walking behavior on comb surfaces, and larval-to-cell-rim distances are discussed in relation to their possible roles in eliciting mite invasion of honey bee larval cells and contrasted to the putative role of kairomones in larval-host location.

Droneflies (Syrphidae: Eristalis spp.) resemble honeybees (Apis mellifera) in appearance and have often been considered to be Batesian mimics. This study used a focal watch technique in order to compare the foraging behaviour of droneflies (Eristalis tenax, Eristalis pertinax, Eristalis arbustorum and Eristalis nemorum) whilst they were feeding on patches of flowers with the behaviour of honeybees and other hymenopterans and dipterans. It was found that, on a range of plant species, the time droneflies spent on individual flowers and the time spent flying between them was more similar to that of honeybees than to the times of other hymenopterans and dipterans. These results suggest that dronefly behaviour has evolved to become more similar to that of honeybees and they support the hypothesis that droneflies are Batesian mimics.

The mitochondrial DNA (mtDNA) from 75 honeybee colonies from the Lebanon was characterized by DraI restriction fragment length polymorphism (RFLP) of the COI-COII intergenic region. The seven observed haplotypes were different enough from all haplotypes already known in Apis mellifera to justify their assignment to a fourth mtDNA lineage. The nucleotide sequence of a 380 base pair (bp) fragment of the NADH2 gene was determined for two haplotypes, which showed a high similarity with two published sequences from A. m. lamarkii and A. m. meda. A microsatellite analysis of a large Lebanese population sample (50 colonies, 8 loci) suggests that Near East populations are also differentiated at the nuclear level from the three previously characterized evolutionary branches of the species A. mellifera.

To understand the effect of abnormal brood odors on the initiation or control of hygienic behavior in honey bees, we employed the associative learning paradigm, proboscis extension reflex conditioning. Bees from two genetic lines(hygienic and non-hygienic) were able to discriminate between high concentrations of two floral odors equally well. Differential discrimination abilities were observed between the two lines when healthy and diseased brood odors were used, with the bees from the hygienic line discriminating between the pair of brood odors better than the non -hygienic bees. These results suggest that hygienic behavior in individual bees is associated with the bees' responses to olfactory stimuli emanating from diseased brood.

We have investigated the effects of long-term ingestion of two serine proteinase inhibitors (PIs), the Kunitz Soybean trypsin inhibitor (SBTI) and Bowman-Birk inhibitor (BBI) on survival, learning abilities involved in the foraging behaviour, and digestive physiology of the honeybee (Apis mellifera L., Hymenoptera). A threshold-dose was established, above which adverse effects of long-term ingestion of the PIs tested are to be expected. The experiments reported herein could be extended to other PIs or gene products used to confer insect resistance, and be part of a general procedure used to assess the innocuousness of transgenic melliferous plants to honeybees.

Sensory preconditioning means that reinforcement of stimulus A after unreinforced exposure to a compound AB also leads to responses to stimulus B. Here, we describe and analyze sensory preconditioning in an insect, the honeybee Apis mellifera. Using two-element odorant compounds in classical conditioning of the proboscis extension reflex, we found (i) that sensory preconditioning is not due to stimulus generalization, (ii) that paired, but not unpaired, presentation of elements supports sensory preconditioning, (iii) that simultaneous, but not sequential, exposure to the elements of the compound supports sensory preconditioning and (iv) that a single presentation of the compound yields maximal sensory preconditioning. The results are discussed with respect to configural and chain-like associative explanations for sensory preconditioning. We suggest an experience-dependent step of compound processing, establishing configural units, as an additional explanation for sensory preconditioning.

The projections to the mushroom bodies (mbs) have been clearly described in the brain of adult honeybees (Apis mellifera). Olfactory projection neurons arborize in the lip of the calyceal neuropil, whereas visual projection neurons project to the collar. To study the maturation of this pattern of innervation, as well as the development of uniglomerular projection neurons within the antennal lobes (als), we conducted the following three studies focused on the first four stages of pupal development: mass staining of olfactory projection neurons, single cell labeling of olfactory projection neurons, and simultaneous labeling of olfactory projection neurons and visual projection neurons. Examination of whole-mount preparations with the confocal laser scanning microscope revealed that the olfactory projection neurons achieved their adult arborization pattern within their main output region, the lip of the mb calyces, earlier during development (pupal stage 1) than their dendritic processes within their main input region, the al (pupal stage 2). Simultaneous labeling experiments showed further that the fiber terminals of olfactory projection neurons and visual projection neurons did not overlap but instead occupied their respective projection areas within the mb calyces as early as pupal stage 1. We conclude that selective innervation of different subregions of the calycal neuropil precedes the segregation of glomerular units within the antennal lobe neuropil, and that the Kenyon cells themselves provide a template for the innervation of olfactory and visual projection neurons.

The USDA-ARS North Central Regional Plant Introduction Station (NCRPIS) in Ames, IA (USA), uses honey bees (Apis mellifera L.) for the pollination of germplasm accessions grown under cages for seed Increase. From 700 to 1000 cages are required each growing season. Each cage is provided a nucleus hive of honey bees containing about 6000 worker bees plus a queen. These hives are too small to overwinter outdoors in Iowa. To provide enough bees for April plantings, we purchase bees from shipping companies located in the southern USA. Package bee purchases are expensive and risk importing unwanted diseases or pests. To reduce costs and overwinter our nucleus colonies locally, we remodeled an existing building to provide an environmentally controlled chamber. Earlier studies demonstrated that four or more frames of physiologically young honey bees are optimal for indoor wintering. Our method has been successful and provides an economical way of wintering small honey bee nucleus colonies for use the following year.

The pollinating entomofauna of faba bean, compared in two locations (Rennes in Brittany and Cordoba in Andalucia), is poorly diversified but very different. In France, it is composed of Bombus terrestris L. (or B. lucorum L.) and of honeybees (Apis mellifera L.) which are not very numerous (number of insects/1000 flowers) and sporadic because of climatic conditions. In Spain, it is mainly composed of one species of Eucera (Eucera numida Lep.) which behaves as a positive pollinator and which is present at high density and frequency. Moreover, in France, the insects often behave as robbers. So, the number of positively visited flowers is 32 times higher in Spain than in France and the insects move more frequently from plant to plant. That could induce a higher outcrossing rate at this location and lead to use a suitable breeding strategy of faba bean for each location.

Plasticity of Dufour's gland secretion in the honey bee is correlated with the individual's plasticity. Queens and queenless (QL) egg-laying workers possess a bouquet of esters and hydrocarbons, whereas queenright (QR) workers produce exclusively hydrocarbons. The effects of social environment (QR vs. QL conditions) and possible physiological constraints on the gland were studied by following the biosynthesis of these classes of compounds in vivo and in vitro. Biosynthesis in vivo followed the prediction based on glandular chemistry. Queens and QL egg-laying workers, but not QR workers or QL foragers, showed incorporation of sodium acetate into both hydrocarbons and esters. In contrast, the in vitro studies revealed that, in addition to queens and QL egg-laying workers, QR nurses retained their ability to produce the queen characteristic esters. Although there was some ester production in foragers, it occurred to a lesser extent. It is possible that the glands in the older foragers undergo irreversible changes. The in vitro incubation also revealed a temporal activation of ester biosynthesis in QR workers. In these glands alcohols, corresponding to the alcohol moiety of the esters, predominated in short-term incubations but decreased as the amount of newly synthesized esters increased. In contrast, queens and QL egg-laying workers showed predominant incorporation into esters from the onset of incubation. Thus, expression within the workers' Dufour's gland is regulated. In the presence of a queen, ester production is inhibited. Once the queen is removed the physiologically unconstrained gland starts to biosynthesize the queen-specific esters after a certain lag needed for the build-up of precursors and the enzymatic machinery.

Individually restrained worker bees were trained to recognize complex odors in a conditioned proboscis extension assay. Three groups of bees were considered, based on the responses recorded during the experimental procedure: selective learners, nonselective learners, and nonlearners. For conditioning, three concentrations of two synthetic mixtures were used. The distribution of bees between groups was not significantly affected by the nature or by the concentration of the conditioning mixture. After conditioning, bees were tested with the individual compounds, and the responses were analyzed with respect to the three groups. Selective learners showed discriminative responses to a few key compounds, while nonselective learners responded to all the compounds, and nonlearners to none. These results showed that complex odor recognition is based on the recognition of key components and relies on the ability of bees to learn.

Hygienic behaviour performed by middle-aged worker bees is an important intranidal task in colonies of the honey bee Apis mellifera (L.). It comprises detecting diseased brood in the larval and pupal stages and removing all such infected brood, thereby decreasing the incidence of infection. Hygienic behaviour consists of two task-components: uncapping cells and removing the cell contents. The aim of this study was to observe bees performing hygienic behaviour to determine their age at performance of the behaviour and to describe their behavioural repertoire. The bees performing hygienic behaviour were middle-aged bees, younger than foragers. In the colonies where the behaviours of individual bees were observed, all bees performing the hygienic behaviour were seen to exhibit both the components, though at different frequencies. One behavioural class performed the task of uncapping cells at higher frequencies than the task of removing cell contents, while another class performed both tasks to the same extent. While these two classes had higher frequencies of the tasks comprising the hygienic behaviour but lower frequencies of other common behaviours in their repertoire, a third class of bees included those that performed all behaviours in their repertoire at similar frequencies. There was no difference in the ages of the bees in these three behavioural classes. These results suggest that there is no evidence of task partitioning among bees performing the hygienic behaviour. The segregation observed could, however, be based on their response thresholds to the stimulus and/or on their ability to discriminate the various cues emanating from the dead brood.

Physiological studies have provided evidence for the existence of ryanodine receptor (RyR) Ca2+ channels in compound eyes of insects. The present study identifies and localizes RyR in insect photoreceptors by use of an affinity-purified antibody against lobster muscle RyR. Western blotting and indirect immunofluorescence staining confirm cross-reactivity of the antibody with insect muscle RyR. In both honeybee and fly eyes, the antibody identifies a single protein that comigrates with muscle RyR on sodium dodecylsulfate (SDS) polyacrylamide gels demonstrating that RyR is present in this tissue. By confocal immunofluorescence microscopy on honeybee eyes, RyR is detected within the photoreceptors and shows a nonhomogeneous distribution over the endoplasmic reticulum (ER). Double labeling studies have demonstrated further that RyR is localized at distinct ER elements close to the light-sensitive microvilli and juxtaposed to adherens junctions. RyR has also been observed within the remaining soma of honeybee photoreceptors, being concentrated on ER cisternae close to mitochondria and the nonreceptive plasma membrane. For comparative purposes, the distribution of RyR has also been assayed in compound eyes of flies. In both Calliphora and Drosophila photoreceptors, the anti-RyR antibody provides punctate labeling throughout the cell body. The submicrovillar ER cisternae associated with the base of the microvilli, however, are only lightly labeled for RyR. These results suggest that RyR is involved with Ca2+ regulation in the nonreceptive cell area of both fly and honeybee photoreceptors, but that it may contribute to Ca2+ regulation close to the phototransduction compartment only in the latter cell.

This is a systematic study of the discrimination of black radially symmetrical patterns presented on a white vertical background and subtending 45degree or 50degree at the point of choice in a Y-maze apparatus. Before discrimination can occur, the ability to fixate is promoted by any radial pattern irrespective of the number of symmetry axes. A ring of spots can also stabilize the eye before the positions of the spots are discriminated. Cues for discrimination are of two main types. First, with fixed patterns of sectors or spots, the cue is the location of an area of black relative to the fixation point, and the particular number of axes is less important than the size of the individual areas. Secondly, evidence is presented for a family of filters with large fields and coarse tuning that detect patterns of radially symmetrical edges. These filters become more evident when the patterns are made of thin black radial bars or when they are rotated at random during the training. An angular shift of one radial pattern relative to the other, or a difference between numbers of bars, is best discriminated when one of the patterns but not the other has angles of 30degree, 60degree, or 120degree between radial edges, and least when the angles are 90degree. Baffles in the apparatus make the bees pause and fixate so that discrimination is improved. When targets are rotated during the learning process, radial cues for discriminations must be presented as edges, not as spots or areas. Besides detecting and fixating flowers, this system could be useful to estimate the perfection of their symmetry.

Population genetics theory suggests that two species which are reproductively isolated only by postzygotic barriers cannot co-exist in sympatry since the rarer population will become extinct. Mimulus nudatus and Mimulus guttatus are two closely related species that are isolated by a postzygotic barrier operating at the seed provisioning stage. On several sites on the serpentine soils of Lake and Napa counties, California, M. nudatus and M. guttatus live in sympatry and flowering times of the species overlap, so the species are sometimes flowering next to each other. We investigated whether there was any reduction in fertility of M. nudatus and M. guttatus caused by interspecific crosses when growing in sympatry. The pollinators of M. nudatus and M. guttatus were identified. Small sweat bees, Dialictus sp., preferentially visited the smaller flowered M. nudatus species and honey bees, Apis mellifera, preferred the larger flowered M. guttatus. In spite of most pollinator visits being intra-specific, individuals of both bee species made transitions between the Mimulus species. This will result in greater pollen transfer from M. guttatus to M. nudatus than vice versa because firstly, M. guttatus produces more pollen and secondly, the sweat bees were too small to touch the stigma of a M. guttatus flower. This asymmetry in gene flow was detected by a greater reduction in viable seed produced by M. nudatus plants when surrounded by M. guttatus plants than vice versa. Only when M. nudatus was the maternal parent could any hybrids be detected in field produced seed. To enable M. nudatus and M. guttatus to co-exist in sympatry, the two species may thus need to be sufficiently ecologically different. Such ecological differentiation was attributed to the greater drought tolerance of M. nudatus. In addition, greenhouse experiments suggested that M. nudatus may have evolved greater tolerance to calcium deficient soils.

Africanized honey bees are more tolerant of infestations with the mite Varroa jacobsoni than are honey bees of European origin. The capacity of these bees to detect and react to brood infested with this mite could be one of the factors determining this tolerance. We tested colonies of Africanized bees headed by queens from swarms collected in Ribeirao Preto, Sao Paulo State. The Italian colonies had queens imported directly from the USA, or from the Brazilian Island of Fernando de Noronha, where varroa -infested Italian colonies have been maintained, untreated, since 1984. Recently sealed worker brood cells were artificially infested by opening the cell capping, inserting live adult female mites and resealing the cells. Control cells were treated in the same way, but without introducing mites. The ability of the Africanized honey bees to recognize and remove this artificially infested brood was compared with that of first generation Italian/Africanized hybrid bees, and with the two groups of "pure" Italian bees, in three separate experiments. Africanized colonies removed a mean of 51% of the infested brood, while Italian/Africanized hybrid colonies removed 25%. Africanized colonies also removed a significantly greater proportion of infested brood than did Italian colonies, headed by queens from the USA (59 vs. 31%, respectively). Similarly, when Africanized colonies were compared with colonies of Italian bees from Fernando de Noronha, the former were found to be significantly more efficient at removing infested brood (61 vs. 35%, respectively), even though the population of Italian bees on this island has been exposed to and survived varroa infestations (without treatment) for more than 12 years. Only the Africanized honey bees removed a significant proportion of varroa-infested brood, when the data was corrected for brood removal from control cells.

The influence of a virgin queen on the longevity of Africanized honeybee workers (Apis mellifera L.) confined into wooden laboratory boxes was evaluated. The bees were caged by groups from 10 to 50 individuals and received candy and water daily renovated, being maintained in a room under controlled environmental conditions. A significant variation of longevity among honeybee workers from different colonies was observed. A group size effect on bee longevity was observed in the presence as well in the absence of queen. The higher survival values were recorded for the groups with 30 to 50 bee workers. More often than not, the life span of workers caged with a queen was greater in relation to that recorded for their sisters maintained without queen, but this biological effect was not detected in the group with 30 bees. Nevertheless, the presence of queen did not affect the longevity of the workers from all colonies. The group size effect on workers longevity also depended on the bee origin, and was less noticeable in small groups (10 - 20 bees), which survived less in relation to the other groups. The groups from 30 to 50 workers were more suitable to maintain virgin queens in laboratory conditions.

Apis mellifera queen rearing is an activity of great importance for the beekeepers, since this technique provide conditions for the development of selection programs to get the improvement of colonies for honey production and other traits of economic interest, or simply the maintenance of each population by periodical substitution of old queens. The breeder queens are selected for their ability to pass recognizable good characteristics to their progeny. The queens produced from the larvae of one or more of these selected breeders are observed through to their performance in heading colonies. This review deals with aspects of the main techniques of queen production, the factors that affect directly the rearing methods and the mean revenue registered by many authors under variable experimental conditions. Particularities on the natural fecundation of Apis mellifera queens considering the influence of environmental factors on successful matings are also discussed.

The impact of drifting workers and drones on evaluating performance data of honeybee (Apis mellifera carnica) colonies was studied using DNA microsatellites. Colony size, honey yield and colony level of infestation with Varroa jacobsoni were evaluated from 30 queenright colonies. Individuals (n = 1359 workers from 38 colonies, n = 449 drones from 14 colonies) were genotyped using four DNA microsatellite loci. Maternity testing was used to identify drifted individuals. The drifting of workers ranged from 0 to 14% with an average of 5 +- 0.7%. The amount of drifting drones was significantly higher ranging from 3 to 89% (average of 50 +- 6.8%). No significant correlations were observed between the amount of drifting and colony sizes. Likewise, the correlations between drifting workers and drones with the phenotypic variance for colony honey yields and levels of infestation with V. jacobsoni were weak and in no case significant. Thus, the low levels of drifting workers (due to performance apiary layout) and the high levels of drifting drones did not interfere with performance testing in this study.

The 374 bp amplicon of 20 Kashmir bee virus (KBV) isolates from 14 bee and 6 mite samples from California was sequenced. The sequence data and those of homologous KBV amplicons of one bee each from Australia, Canada, Maine, and Maryland were analyzed. Pairwise comparisons of nucleotide sequences show the mean distance between Californian isolates varying from 0% to 3.2%. The mean distance between Californian isolates and the two U.S. or the Canadian isolates are equal or less than 3.2%. The Australian isolate is different from all North American isolates with mean distances of 11.5 to 12.3%. This 374 bp sequence contains a single open reading frame, the 124 amino acid sequence matched closely with the sequences of many virus polyproteins.

Tergal gland morphology was investigated for Apis mellifera capensis and A. m. scutellata virgin queens and workers. Workers exhibit two types of tergal glands. Type-A glands consist of single cells, are located along the anterior edge of the tergites II-V, characterised by numerous mitochondria and rough endoplasmic reticulum, and closely associated with fat cells and oenocytes. Type-B tergal glands are bicellular and found predominantly in capensis queens and workers and in scutellata queens. These type-B glands occur along the posterior edge of tergites II-V and are characterised by secretory cells with numerous mitochondria, end apparatuses, and secretory vesicles. There were no differences in gland location or structure in the honeybee queens of both races. However capensis workers possess more glands of both types and larger type-A gland cells than scutellata workers. This result further emphasises the distinctiveness of Cape honeybees.

Resting potentials in Apis mellifera and Drosophila melanogaster flight muscles decrease with falling temperatures. When resting potentials fall to between -37 and -45 mV they activate a final burst of spontaneous muscle action potentials (MAPs). This final burst of MAPs marks the beginning of chill-coma for each species. The temperature at which the final burst occurs for D. melanogaster (7.0+-0.9degreeC) is significantly lower than that of A. mellifera workers (10.6+-1.2degreeC), queens (10.2+ -0.8degreeC), and drones (12.8+-0.8degreeC). Prior to chill-coma, MAP amplitudes decrease and durations increase with falling temperatures in both A. mellifera and D. melanogaster. The rate of these changes and the temperatures at which they occur appear to be related to the rate of decline in each species' resting potential. These results suggest that insect chill-coma varies with a species' ability to maintain its resting potential at low temperatures.

This study describes the ultrastructural differences between the compound eyes of chli/chli and Ch/chli honeybee queens. Heterozygous "limao" bees had an almost normal ultrastructural organization of the ommatidia, but there were some alterations, including small vacuoles in the crystalline cones and a loss of pigment by primary pigmentary cells. In homozygous bees many ommatidia had very deformed crystalline cones and there were some bipartite rhabdoma. There was a reduction in the amount of pigment in the primary and secondary pigmentary cells and receptor cells (retinulae) of mutant eyes. However, the eyes of both heterozygous and homozygous queens had the same type of pigment granules. Certain membrane-limited structures containing pigment granules and electron-dense material appeared to be of lysosomal nature. Since these structures occurred in the retinular cells of mutant eyes, they were considered to be multivesicular bodies responsible for the reduction in rhabdom volume in the presence of light, as a type of adaptation to brightness. The reduction of pigment in the pigmentary and retinular cells and the morphological changes seen in the rhabdom of the ommatidia may originate visual deficiencies, which could explain the behavioral modifications reported for Apis mellifera queens with mutant eye color.

This paper presents the protein profiles of hypopharyngeal glands of aged Apis mellifera workers (40 days old), experimentally induced during the later phase of their adult life to return to the task of brood care due to the absence of younger bees (experimental condition). This pattern was similar to that of 12-day old workers reared under normal and experimental conditions, suggesting glandular reactivation. A different and specific electrophoretical pattern was observed in 40-day old workers from a normal colony.

New information published since 1995 about propolis constituents is reviewed. The available information on the biological action of new found components is presented. Recent publications are reviewed on propolis of native South American stingless bees. The plant sources of bee glue are discussed, taking into consideration data based on reliable chemical evidence including comparisons between propolis samples and plant material. Some aspects of the chemical standardization of propolis are discussed.

The acceptance threshold model predicts that in a fluctuating environment a recognition system should be adaptive rather than fixed. In particular, discriminating individuals, such as guards at a nest entrance, should be less permissive to conspecifics when both the frequency of non-nest-mate contact and the cost of accepting non-nest mates is high. We tested these predictions by studying honey bee guarding during a period in which nectar conditions changed from dearth to abundance. Initially, during nectar dearth, individual guards accepted 80% of introduced nest mates and 25% of non-nest mates. As nectar conditions improved, both the intensity of robbing and guarding and the cost of non-nest-mate acceptance declined. In response, individual guards became more permissive to nest mates and non -nest mates until eventually an "accept-all" threshold occurred-all nest mates and non-nest mates were accepted. These data are consistent with a shifting acceptance threshold and provide the first field data to support the model. A simple linear relationship occurred between the number of guards and the number of fights, 9:1, observed at the hive entrance, suggesting that guarding may be regulated by intruder intensity or otherwise regulated in an adaptive manner.

Amino acids are common constituents of floral nectars and can be critical components in the diets of insect pollinators. Yet the means through which insects detect amino acids can be complex and arise from pre- and post -ingestive mechanisms. Furthermore, the response to an amino acid can change depending on an insect's nutritional status. Here we use a sensitive feeding assay and Proboscis Extension Response (PER) conditioning in the honey bee to assay the effect of glycine, which is a common constituent of nectars and pollens. Subjects preferred to feed on a sucrose stimulus that contained glycine, and the highest relative preference was recorded for the highest concentration of glycine. However, the highest response rate occurred at lower than maximal concentrations and differed depending on the physiological status of the subjects. These results are consistent with a model in which subjects attempt to maintain a physiological target amount of glycine/amino acid relative to other nutrients. All concentrations of glycine enhanced the rate and magnitude of a conditioned response to an odor in the PER assay, which demonstrates that animals can learn to modify their responses to an odor conditioned stimulus based on the presence of amino acid. This capability would enhance a honey bee's ability to evaluate the quality of floral nectars, which are associated with, among other things, odor cues given off by flowers. In future studies these techniques will allow us to evaluate the physiological roles that amino acids play in honey bee diet and choice behavior.

Pollen sources used by a colony of Apis mellifera and four colonies of some species of Trigonini were compared during the months of October and November of 1996 in the Campus of Escola Superior de Agricultura Luiz de Queiroz, Piracicaba, State of Sao Paulo, Brazil (22degree43'S; 47degree25'W; altitude: 580 m). The identification of the vegetable species visited by bees was through the pollen found in the masses located in the workers' pollen basket of the studied species. Fifty-three types of pollen were identified, and the largest similarity percentage in the use of the pollen sources was between Nannotrigona testaceicornis and Tetragonisca angustula and the smallest between A. mellifera and T. angustula. The sequence of the species with larger width of the niche food was A. mellifera followed by Plebeia droryana, Partamona helleri, T. angustula and N. testaceicornis, while for the uniformity of use of the pollen sources it was P. helleri, P. droryana, A. mellifera, N. testaceicornis and T. angustula.

In anarchistic honey-bee colonies, many workers' sons are reared despite the presence of the queen. Worker-laid eggs are normally eaten by other workers in queen-right colonies. Workers are thought to discriminate between queen-laid and worker-laid eggs by the presence or absence of a queen-produced egg-marking pheromone. This study compared the survival of three classes of eggs (worker-laid eggs from anarchistic colonies, worker -laid eggs from non-anarchistic queenless colonies, and queen-laid eggs) in both queenright normal colonies and queenright anarchistic colonies, in order to test the hypothesis that anarchistic workers evade policing by laying more acceptable eggs. As expected, few worker-laid eggs from non -anarchistic colonies survived more than 2 h. In contrast, worker-laid eggs from anarchistic colonies had much greater acceptability, which in some trials equalled the acceptability of queen-laid eggs. Anarchistic colonies were generally less discriminatory than normal queenright colonies towards worker-laid eggs, whether these originated from anarchistic colonies or normal queenless colonies. This indicates that the egg-removal aspect of the anarchistic syndrome involves both worker laying of eggs with greater acceptability and reduced discriminatory behaviour of policing workers.

The variations of neural metabolism induced by surgical and chemical treatments were studied in the honeybee brain by the means of cytochrome oxidase (CO) histochemistry. CO staining is considerably reduced in the alpha-lobe by antennal input deprivation. Chemical stimulation (50 mM K+) was linked to an increase of CO staining in antennal lobes (AL) and to a decrease in the basal ring of calyces (Cal). Application of the nicotinic ligand imidacloprid (10-4 M) resulted in increased CO labelling within 30 min in all the structures analysed. Treatment with a lower concentration (10-8 M) resulted in reduced staining in Cal and central body (CB). We conclude that CO histochemistry can be used to identify the target structures of cholinergic ligands in the honeybee brain.

The impact of a parasitic infestation may be influenced by nutritional state, in both individuals and colonies. This study examined the interaction between pollen storage and the effects of an infestation by the mite, Varroa jacobsoni Oudemans, in colonies of the honey bee, Apis mellifera L. We manipulated the pollen storage and mite infestation levels of colonies, and measured pollen foraging and brood rearing. Increased pollen stores decreased both the number of pollen foragers and pollen load size, while initially at least foragers from colonies with moderate infestations carried smaller pollen loads than those from lightly infested colonies. Over the course of the experiment, all colonies significantly increased pollen-foraging rates and pollen consumption, which was presumably a seasonal effect. Lightly infested colonies exhibited a larger increase in pollen forager number than moderately infested colonies, suggesting that more intense mite infestations compromised forager recruitment. Brood production was not affected by the addition of pollen, but moderately infested colonies were rearing significantly less brood by the end of the experiment than lightly infested colonies. Furthermore, the efficiency with which colonies converted pollen to brood decreased as the pollen storage level decreased and the infestation level increased. The results of this study may indicate that honey bee colonies adaptively alter brood-production efficiency in response to parasitic infestations and seasonal changes.

The biochemical bases for the high mass-specific metabolic rates of flying insects remain poorly understood. To gain insights into mitochondrial function during flight, metabolic rates of individual flying honeybees were measured using respirometry, and their thoracic muscles were fixed for electron microscopy. Mitochondrial volume densities and cristae surface densities, combined with biochemical data concerning cytochrome content per unit mass, were used to estimate respiratory chain enzyme densities per unit cristae surface area. Despite the high content of respiratory enzymes per unit muscle mass, these are accommodated by abundant mitochondria and high cristae surface densities such that enzyme densities per unit cristae surface area are similar to those found in mammalian muscle and liver. These results support the idea that a unit area of mitochondrial inner membrane constitutes an invariant structural unit. Rates of O2 consumption per unit cristae surface area are much higher than those estimated in mammals as a consequence of higher enzyme turnover rates (electron transfer rates per enzyme molecule) during flight. Cytochrome c oxidase, in particular, operates close to its maximum catalytic capacity (kcat). Thus, high flux rates are achieved via (i) high respiratory enzyme content per unit muscle mass and (ii) the operation of these enzymes at high fractional velocities.

The metabolic rate of free flying honeybees (Apis mellifera ligustica) foraging on a multiple automatic feeder was measured in complete absence of perturbation. Each time the sucrose flow rate was doubled, the metabolic rate increased by 18.2 +- 2.0% (14.7 mul CO2 min-1) and final crop load by 25.1 +- 2.4% (7.04 mul). The possibility that the heavier load carried by the bees caused the increase in the metabolic rate was analyzed in detail. It was found that, for the same weight in the crop, the metabolic rate increased with the increasing reward rate. Therefore, a factor other than the carried weight might account for this increase: a motivational drive, whose intensity may depend on the reward rate at the food source. Although at higher reward rates metabolic rate increased during the visit, at lower reward rates it remained constant, suggesting that the effect of the carried weight on the metabolic rate might be controlled by this motivational drive. The hypothesis that honeybees maximize individual efficiency by reducing their crop load loses support, as foraging costs are not determined by the carried weight. The functional meaning of the reduction in crop load would be to increase the informational exchange at the hive.

The interplay between the recruitment dance and food-giving trophallactic contacts of returning Apis mellifera foragers was analyzed. Dancing and trophallactic events were recorded for bees returning from a rate feeder that provided 50% weight on weight sucrose solution at a constant flow rate of 5 mul min-1. Bees that had danced immediately before their trophallactic contact had more recipients per trophallaxis compared with bees that did not dance before. Thus, besides information coded in dancing behavior, dance maneuvers could serve as a stimulus to increase attention of bees located on the dance floor to receive nectar. In addition, the number of bees receiving food during a trophallaxis showed a positive correlation with the probability of dancing immediately after contacting. The time from arrival at the hive to when the first or the subsequent contacts took place presented no correlation with the probability of dancing after trophallaxis. Also, the duration of a trophallaxis was positively correlated with the number of recipients per trophallaxis. These results suggest that returning foragers could receive information during a trophallactic contact with their hive mates that modify thresholds for dancing. Dance maneuvers and trophallactic contacts performed by foraging bees seem to be "mutually" affected.

To test the hypothesis that colonies of honey bees composed of workers with faster rates of adult behavioral development are more defensive than colonies composed of workers with slower behavioral development, we determined whether there is a correlation between genetic variation in worker temporal polyethism and colony defensiveness. There was a positive correlation for these two traits, both for European and Africanized honey bees. The correlation was larger for Africanized bees, due to differences between Africanized and European bees, differences in experimental design, or both. Consistent with these results was the finding that colonies with a higher proportion of older bees were more defensive than colonies of the same size that had a lower proportion of older bees. There also was a positive correlation between rate of individual behavioral development and the intensity of colony flight activity, and a negative correlation between colony defensiveness and flight activity. This suggests that the relationship between temporal polyethism and colony defensiveness may vary with the manner in which foraging and defense duties are allocated among a colony's older workers. These results indicate that genotypic differences in rates of worker behavioral development can influence the phenotype of a honey bee colony in a variety of ways.

Foraging by honeybee workers was investigated from the moment of the first foraging flight until death. To minimise the influence of factors other than senescence the foragers were trained to collect food from an artificial flower close to their hive. During each foraging trip the workers repeatedly visited an artificial flower, collecting one microlitre of 50% sugar solution per visit. During the first 50 flights the mean time taken to collect one portion of food decreased significantly and the number of visits to the artificial flower per flight increased significantly. During flights following the 50th flight, the mean time taken to collect one portion of food increased significantly and the number of visits to the artificial flower per flight decreased significantly. The results confirm earlier observations that the foraging behaviour of honeybee workers is not only influenced by learning, but also by the effects of senescence.

Morphometric and flight dimensional characters of worker honeybees, Apis mellifera Linnaeus, from equatorial Gabon were analysed by multivariate methods to characterize the population. A single morphocluster and a single flight dimension cluster were obtained. When these bees were grouped together with those of other countries of the region, again a single morphocluster and flight cluster were obtained. All of the outlier samples were previously designated as Apis mellifera adansonii Latreille and completely surround the Gabon samples, establishing the same subspecies membership for the latter. The bees of Gabon are morphometrically more homogeneous than in any other area of Africa.

Young queens start a new colony either without (independently) or with the help of workers (dependently). When colony reproduction is dependent and young queens are produced in excess, conflicts among queens are predicted to occur. Honey bee colonies reproduce dependently by swarming. The mother queen leaves with a "prime swarm" before daughter queens reach adulthood. Several young queens are produced, and often fight to death after emergence. Surviving queen(s) inherit the established nest or a portion of workers which then depart in an "afterswarm". Honey bee queens show traits considered to be adaptations for fighting and conflict with other queens, such as early venom production and fast development. During fights one of the queens often releases rectal fluid. The function of this "spraying" behaviour is unclear. Possible functions of spraying are to affect worker intervention in fights, to act as a chemical weapon, or to interrupt fights. We staged fights between 24 queen pairs to investigate the temporal pattern of behaviour in spraying and non-spraying fights. Spraying occurred in 67% of the fights, usually upon physical contact, and it resulted in at least temporary separation of the queens in 81% of the spraying fights. Spraying fights were characterized by a significantly lower proportion of time spent in escalated aggression than non-spraying fights and a significantly shorter first escalated bout. This provides quantitative evidence that spraying interrupts fights and suggests that its function is to provide a temporary respite to the spraying queen.

Juvenile hormone III (JH) haemolymph titres were quantified in adult worker honey bees under colony conditions conducive to either typical or accelerated behavioural development. JH titres of bees under conditions of accelerated behavioural development were significantly higher than same -aged bees under more typical conditions, even before the onset of foraging. These results are consistent with previous findings indicating that JH plays a causal role in timing the onset of foraging behaviour in honey bees. We also detected a peak of JH in 2-3 day old adult bees, the significance of which is unknown.

Honeybee, Apis mellifera, colonies replace their queens by constructing many queen cells and then eliminating supernumerary queens until only one remains. The ages of the queens and the variation in their reproductive potential are important factors in the outcome of such events. Selection would favour colonies that requeen as quickly as possible to minimize the brood hiatus, therefore selecting for queens reared from older larvae. Conversely, reproductive potential (queen 'quality') is maximized by rearing queens from younger larvae. This potential trade-off was tested during two phases of queen replacement, namely queen rearing and polygyny reduction. Our results suggest that queenage is a significant element during both queen rearing and polygyny reduction, whereas queen quality, at least to the magnitude tested in this experiment, has little impact on the outcome of either process. The rate of queen replacement therefore appears to be an important factor in the honeybee life cycle, and further mechanisms of potential importance during this life history transition are discussed.

Honeybees, Apis mellifera, adjust their pollen foraging activity according to the need for pollen within the colony, determined by the amount of stored pollen and young brood present in the hive. To clarify how pollen foragers detect the supply of pollen, we followed individual honeybees while they were returning with pollen. Pollen foragers deposited their loads on the frame where most of the unsealed brood was, independent of the position of this frame within the hive. They also inspected more cells on that frame and spent most of their time there, indicating that pollen foragers may individually evaluate the pollen requirements of the colony. In 18 normal-sized colonies we also tested whether olfactory cues provided by a frame of hungry young brood or an additional pollen frame covered by cages affect foraging activity. These experiments showed that olfactory stimulation within the colony is insufficient to increase or decrease the foraging effort, but suggest that foragers must have direct contact with the brood and pollen area to regulate their foraging activity according to the conditions in the colony. The different mechanisms by which foragers may gather the information about pollen supply are discussed.

In recent years significant progress has been made in the analysis of the cellular mechanisms underlying appetitive learning in two invertebrate species, the pond snail Lymnaea stagnalis and the honeybee Apis mellifera. In Lymnaea, both chemical (taste) and tactile appetitive conditioning paradigms were used and cellular traces of behavioural classical conditioning were recorded at several specific sites in the nervous system. These sites included sensory pathways, central pattern generator and modulatory interneurones as well as motoneurones of the feeding network. In the honeybee, a chemical (odour) appetitive conditioning paradigm resulted in cellular changes at different sites in the nervous system. In both the pond snail and the honeybee the activation of identified modulatory interneurones could substitute for the use of the chemical unconditioned stimulus, making these paradigms even more amenable to more detailed cellular and molecular analysis.

Malformed antennae of Apis mellifera light ocelli drones were drawn, dissected and mounted permanently on slides containing Canada balsam, in order to count the olfactory discs present in each segment, in comparison with the number of those structures in normal antennae of their brothers. Some drones presented morphological abnormalities in a single segment of the right or left antenna, but others had two or more malformed segments in a same antenna. Drones with malformations in both antennae were also observed. The 4th and 5th flagellum segments were the most frequently affected. In a low number of cases the frequency of olfactory discs in malformed segments did not differ from that one recorded for normal segments. However, in most cases studied, the antennal malformations brought about a significant reduction in the number of olfactory discs from malformed segments.

The mushroom bodies of the insect brain are centers for olfactory and multimodal information processing and they are involved in associative olfactory learning. They are comprised of numerous (340,000 in the bee brain), small (3-8 mum soma diameter) local interneurons, the Kenyon cells. In the brain of honeybees (Apis mellifera) of all castes (worker bees, drones and queens), wasps (Vespula germanica) and hornets (Vespa crabro) immunostaining revealed fibers with dopamine-like immunoreactivity projecting from the pedunculus and the lip neuropil of the mushroom bodies into the Kenyon cell perikaryal layer. These fibers terminate with numerous varicosities, mainly around the border between medial and lateral Kenyon cell soma groups. Visualization of immunostained terminals in the transmission electron microscope showed that they directly contact the somata of the Kenyon cells and contain presynaptic elements. The somata of the Kenyon cells are clearly non-immunoreactive. Synaptic contacts at the somata are unusual for the central nervous systems of insects and other arthropods. This finding suggests that the somata of the Kenyon cells of Hymenoptera may serve an integrative role, and not merely a supportive function.

Biogenic amine receptors are involved in the regulation and modulation of various physiological and behavioral processes in both vertebrates and invertebrates. We have cloned a member of this gene family from the CNS of the honeybee, Apis mellifera. The deduced amino acid sequence is homologous to tyramine receptors cloned from Locusta migratoria and Drosophila melanogaster as well as to an octopamine receptor cloned from Heliothis virescens. Functional properties of the honeybee receptor were studied in stably transfected human embryonic kidney 293 cells. Tyramine reduced forskolin-induced cyclic AMP production in a dose-dependent manner with an EC50 of apprx130 nM. A similar effect of tyramine was observed in membrane homogenates of honeybee brains. Octopamine also reduced cyclic AMP production in the transfected cell line but was both less potent (EC50 of apprx30 muM) and less efficacious than tyramine. Receptor-encoding mRNA has a widespread distribution in the brain and subesophageal ganglion of the honeybee, suggesting that this tyramine receptor is involved in sensory signal processing as well as in higher-order brain functions.

We have cloned and characterized a cDNA encoding a putative glutamate transporter, Am-EAAT, from the brain of the honeybee, Apis mellifera. The 543-amino-acid AmEAAT gene product shares the highest sequence identity (54%) with the human EAAT2 subtype. Am-EAAT is expressed predominantly in the brain, and its transcripts are abundant in the optic lobes and inner compact Kenyon cells of the mushroom bodies (MBs). with most other regions of the brain showing lower levels of Am-EAAT expression. High levels of Am -EAAT message are found in pupal stages, possibly indicating a role for glutamate in the developing brain.

Twenty-five unique CfoI-generated whole-cell DNA profiles were identified in a study of 30 Paenibacillus alvei isolates cultured from honey and diseased larvae collected from honeybee (Apis mellifera) colonies in geographically diverse areas in Australia. The fingerprint patterns were highly variable and readily discernible from one another, which highlighted the potential of this method for tracing the movement of isolates in epidemiological studies. 16S rRNA gene fragments (length, 1,416 bp) for all 30 isolates were enzymatically amplified by PCR and subjected to restriction analysis with DraI, HinfI, CfoI, AluI, FokI, and RsaI. With each enzyme the restriction profiles of the 16S rRNA genes from all 30 isolates were identical (one restriction fragment length polymorphism (RFLP) was observed in the HinfI profile of the 16S rRNA gene from isolate 17), which confirmed that the isolates belonged to the same species. The restriction profiles generated by using DraI, FokI, and HinfI differentiated P. alvei from the phylogenetically closely related species Paenibacillus macerans and Paenibacillus macquariensis. Alveolysin gene fragments (length, 1,555 bp) were enzymatically amplified from some of the P. alvei isolates (19 of 30 isolates), and RFLP were detected by using the enzymes CfoI, Sau3AI, and RsaI. Extrachromosomal DNA ranging in size from 1 to 10 kb was detected in 17 of 30 (57%) P. alvei whole-cell DNA profiles. Extensive biochemical heterogeneity was observed among the 28 P. alvei isolates examined with the API 50CHB system. All of these isolates were catalase, oxidase, and Voges-Proskauer positive and nitrate negative, and all produced acid when glycerol, esculin, and maltose were added. The isolates produced variable results for 16 of the 49 biochemical tests; negative reactions were recorded in the remaining 30 assays. The genetic and biochemical heterogeneity in P. alvei isolates may be a reflection of adaptation to the special habitats in which they originated.

Cytochrome P450 partial sequences were isolated by PCR using genomic DNA from two hymenopteran insects of agronomical importance, Trichogramma cacoeciae, a parasitoid wasp, and Apis mellifera, the honeybee. Four new P450 genes were identified: one honeybee gene belongs to the CYP4 family and was named CYP4G11; the three other genes were from Trichogramma and belong to the CYP4 family (CYP4G12) and to a novel family, the CYP48 one (CYP48A1 and CYP48A2). The four genes contain a short intron (72-95 bp) at the same position as already described for other insect species. The two genes CYP48A1 and CYP48A2 have a supernumary intron (57-71 bp) upstream the first one. Only the two CYP4 genes were constitutively transcribed, at a high level for CYP4G12 and at a low level for CYP4G11. No expression was observed for CYP48A1 and CYP48A2.

We have previously used the differential display method to identify a gene that is expressed preferentially in the mushroom bodies of worker honeybees and to show that it encodes a putative inositol 1,4,5 -trisphosphate receptor (IP3R) homologue (Kamikouchi et al. (1998) Biochem. Biophys. Res. Commun. 242:181-186). In the present study, we examined whether the expression of some of the genes for proteins involved in the intracellular Ca2+ signal transduction is also concentrated in the mushroom bodies of the honeybee by isolating cDNA fragments that encode the Ca2+/calmodulin-dependent protein kinase II (CaMKII) and protein kinase C (PKC) homologues of the honeybee. In situ hybridization analysis revealed that the expression of these genes was also concentrated in the mushroom bodies of the honeybee brain: The CaMKII gene was expressed preferentially in the large-type Kenyon cells of the mushroom bodies, whereas that for PKC was expressed in both the large and small types of Kenyon cells. The expression of the genes for IP3R and CaMKII was concentrated in the mushroom bodies of the queen and drone as well as in those of the worker bee. Furthermore, the enzymatic activities of CaMKII and PKC were found to be higher in the mushroom bodies/central bodies than in the optic and antennal lobes of the worker bee brain. These results suggest that the function of the intracellular Ca2+ signal transduction is enhanced in Kenyon cells in comparison to other neuronal cell types in the honeybee brain.

Behavioral development in the adult worker honey bee (Apis mellifera), from performing tasks inside the hive to foraging, is associated with an increase in the blood titer of juvenile hormone III (JH), and hormone treatment results in precocious foraging. To study behavioral development in the absence of JH we removed its glandular source, the corpora allata, in 1-day-old adult bees. The age at onset of foraging for allatectomized bees in typical colonies was significantly older compared with that of sham-operated bees in 3 out of 4 colonies; this delay was eliminated by hormone replacement in 3 out of 3 colonies. To determine the effects of corpora allata removal on sensitivity to changes in conditions that influence the rate of behavioral development, we used "single-cohort" colonies (composed of only young bees) in which some colony members initiate foraging precociously. The age at onset of foraging for allatectomized bees was significantly older compared with that of sham -operated bees in 2 out of 3 colonies, and this delay was eliminated by hormone replacement. Allatectomized bees initiated foraging at significantly younger ages in single-cohort colonies than in typical colonies. These results demonstrate that JH influences the pace of behavioral development in honey bees, but is not essential for either foraging or altering behavioral development in response to changes in conditions.

A trial was conducted to measure the impact of honeybees (Apis mellifera L.) on faba bean (Vicia faba L.) yields and to determine the value of the crop to honeybees. The seed yield in cages with bees was 25% higher than in those without bees. The pollen harvested by honey bees from the faba beans met their nutritional requirements for protein and amino acids but there was no detectable nectar crop gathered from the faba beans. Thus, there seems to be a strong case for using managed honey bees to improve pollination and hence yields of Australian faba beans where feral bee populations may be insufficient.

Comparative pollination efficiency of three Apis ssp., namely, Apis florea F., A. dorsata F. and A. mellifera L. was studied in Brassica campestris var. 'sarson' B. S. H. 1 at CCS Haryana Agricultural University Farm, Hisar during January 1997. Abundance of different bee species and loose pollen grains sticking on the body surface of the bees were taken as main criteria for determining the pollination index. The pollination index of A. dorsata was found to be highest (121852), while it was lowest (25983) in case of A. florea. Hence, A. dorsata was most efficient pollinator of 'sarson' flowers followed by A. mellifera and A. florea under agro -ecological condition of Hisar.

The hexagon model of color vision predicts that white flowers which reflect ultraviolet light resemble green foliage to a bee's eye, whereas, according to other models of the bee color vision, UV-reflecting white is discriminable from foliage green. The hexagon model is widely used in ecologically and evolutionary oriented literature, and the predicted similarity between white and green has been recently presented as a well established fact (Waser and Chittka 1998). We show that bees detect UV -reflecting white objects presented on a green background, a finding that is in disagreement with the predictions of the hexagon model.

Honeybees Apis mellifera detect coloured targets presented to the frontal region of their compound eyes using their colour vision system at larger visual angles (alpha RGT 15degree), and an achromatic visual system based on the long-wave photoreceptor type at smaller visual angles (5degree LGT alpha LGT 15degree). Here we examine the capability of the dorsal, ventral and frontal regions of the eye for colour detection. The minimum visual angle alphamin at which the bees detect a stimulus providing both chromatic contrast and receptor-specific contrasts to the three receptor types varies for the different regions of the eye: 7.1 +- 0.5degree for the ventral region, 8.2 +- 0.6degree for the dorsal region and 4.0 +- 0.5degree for the frontal region. Flight trajectories show that when the target was presented in the horizontal plane, bees used only the ventral region of their eyes to make their choices. When the targets appeared dorsally, bees used the frontodorsal region. This finding suggests that pure dorsal detection of coloured targets is difficult in this context. Furthermore, alphamin in the ventral plane depends on receptor-specific contrasts. The absence of S-receptor contrast does not affect the performance (alphamin = 5.9 +- 0.5degree), whilst the absence of M- and L -receptor contrast significantly impairs the detection task. Minimal visual angles of 10.3 +- 0.9degree and 17.6 +- 3degree, respectively, are obtained in these cases. Thus, as for many visual tasks, the compound eye of the honeybee shows a regionalisation of colour detection that might be related to peripheral or central specialisations.

A physiological model of dark-adapted and light-adapted photoreceptors in the honeybee worker (Apis mellifera) has been developed. Almost all of the electrophysiological components of photoreceptors known up to date, e.g. the phototransduction cascade, the ion channels of the membrane, phototransduction gain and optical adaptation mechanisms, are adequately described by simple biophysical and biochemical models. The connections of these components were tried out in synthetic simulations for best fits of simulated to intracellularly recorded membrane potentials. Although the parameters of the best model were determined exclusively for the measured membrane potentials of dark-adapted photoreceptors, the model also accurately describes the light-adapted photoreceptor membrane potentials. Furthermore, the model correctly predicts the time-courses of measured photoreceptor responses with respect to squared-modulated flicker lights up to 200 Hz. This clearly demonstrates that the presented photoreceptor model is indeed a physiologically adequate description of the essential components of the phototransduction and the electrical membrane processes in the photoreceptors of the honeybee worker.

Influence of queenless impulse on the haemolymph protein profile of worker honeybees was investigated. In the absence of queen, ovaries of worker bees showed greater development and their haemolymph showed higher protein concentration. SDS-PAGE and scanning of the gel revealed that the proteins resolving at apprx 148, 135, 118, 74 and a number of bands between 67 and 40 kDa got accumulated in the haemolymph. Two bands resolving at apprx 135 and 74 kDa were found to be the most affected proteins which also showed an apparent correlation with the degree of ovarian development and total haemolymph protein concentration. High protein content and accumulation of some proteins in the haemolymph can be believed to fulfil the requirements of developing ovaries. Comparison of results with electrophoretogram of larval haemolymph suggests that the apprx 74 kDa protein might be the larval serum protein (arylphorin). The significance of its reappearance is not clear and needs further investigations.

To study the causal mechanisms underlying the control of egg sex by honeybee queens (Apis mellifera), the queens were allowed to lay eggs in experimental cages without comb cells. The sex of the eggs laid were then determined by counting the number of chromosomes, and by observation of female and male pronuclei in the eggs and sperm cells on the surface of the eggs. It was found that queens laid normally fertilized diploid eggs under the experimental conditions. These results suggested that honeybee queens lay fertilized eggs when no information of comb cell size is available, thus the idea that queens would be stimulated to release sperm by small worker cells fitting queen's abdomen is not supported.

We studied the reproductive biology of two leguminous shrubs endemic of the western Mediterranean region Cytisus striatus (Hill) Rothm. and Retama sphaerocarpa (L.) Boiss. The former is polliniferous, and the latter is nectariferous, with maximum nectar production at the earliest hours of the morning. Germination of the pollen grains in the flowers of the two species occurs only after rupture of the stigmatic surface. It is also necessary in both cases that pollinators (mainly Apis mellifera) visit the flowers for fruit and seed set to occur. A study of the pollen-pistil interaction indicated that there exists prezygotic self-incompatibility in these two species, probably of the gametophytic type, but some self-pollen tubes escape this control and self-fertilize some ovules. However, after hand self-pollination, fruit and seed set is very low for both species. This suggests the existence of a postzygotic rejection mechanism, which could be due either to the existence of late-acting self-incompatibility or to an early action of inbreeding depression, although there are lines of evidence that seem to point to the second possibility. Hand cross -pollination led to an increased number of fruit and seeds per plant relative to the control plants, indicating that reproduction is pollen limited.

This study examines the relative abundance and species richness of bees in sand dunes of the middle Sao Francisco River, Bahia, northeast Brazil. Comparisons were made with other studies in caatinga areas. The sampling took place in March, September, December 1996 and March 1997, using entomological net. The study site is located in Ibiraba (10degree48'S, 42degree50'W), municipal district of Barra, Bahia state. The climate is semi arid hot and dry. The predominant local vegetation is caatinga. A total of 931 individuals and 31 species were netted at flowers or during flight. Most of the species were represented by few individuals and only eight species were abundant, together accounting for 87,6% of the total individuals. Anthophoridae showed the highest number of species (52%). Most of the individuals bee (75%) were eusocial Apidae. At specific level, Apis mellifera Linnaeus and Frieseomellita silvestri languida Moure were predominant; 34,9% and 16% of total individuals, respectively. The bees were more abundant during the rainy season; this seasonal pattern was similar to other caatinga areas.

Behavioral studies were conducted of Melittobia digitata Dahms on Apis mellifera (L.) pupae, pupa-shaped glass dummies, flat glass, and flat glass treated with honey bee extract to determine if females use shape or chemicals to identify a host for oviposition. Response to untreated flat glass was consistently lower than that to pupa-shaped glass. Females spent much more time on a pupa-shaped glass object than on a rectangular piece of glass. Time spent antennating on the bee pupa and on the glass pupa did not differ. However, antennation response to extract-treated flat glass and untreated flat glass was lower than that on pupa-shaped glass. The addition of host extract did not increase probing on flat glass. Wasps probed and antennated the glass dummy about as much as the bee pupa but did not respond much to the rectangular glass objects, indicating that shape plays a major role in the process of host acceptance. In these experiments, only bee pupae were accepted for oviposition and never the glass objects. In further experiments, M. digitata was found to oviposit on Parafilm domes containing agar-based diet but not on domes containing only agar. Females responded to both shape and nutritional content of the host but the surface chemical cues tested were unimportant to females considering an object for oviposition.

This paper examines the relationship between endogenous dopamine (DA) levels and the density of (3H)SCH23390-binding sites in the brain of the adult worker honey bee. DA levels were reduced pharmacologically using a single 10 mul injection of either alpha-methyl-DL-p-tyrosine (AMT; 250 mug or 500 mug) or alpha-methyl-DL-tryptophan (AMTP; 250 or 500 mug) into the haemolymph of the bee. In all cases, maximum depletion of DA was observed 3 h after treatment, but in bees treated with AMTP (250 or 500 mug) or with 250 mug AMT, DA levels returned to normal within 24 h of treatment. Neither AMT nor AMTP was selective for DA: both drugs also reduced serotonin (5-hydroxytryptamine, 5HT) levels in the brain. However, AMTP was more effective than AMT at depleting 5HT, whereas for DA, the reverse was true. Depletion of DA levels, using 250 mug AMT, led to a dramatic decline in the levels of specific binding of (3H)SCH23390, defined in this study as binding in the presence of 5 X 10-6 M cis-(Z)-flupentixol (see Ref. (28)). In contrast, naturally occurring diel fluctuations in DA levels, identified in the optic lobes of the brain, and changes in brain DA levels resulting from queenlessness, had no significant effect on the density of (3H)SCH23390-binding sites in the brain of the bee. Overall, these results indicate that under normal physiological conditions, there is no direct link in honey bees between changes in endogenous brain DA levels and the density of D1-like receptors labelled by (3H)SCH23390.

The aim of the present study was to investigate whether melittin, the principal toxin of the honeybee (Apis mellifera) venom, can be used as an algogenic agent in the study of pain in humans. Five micrograms of melittin in 0.5 ml of saline was intradermally injected into the volar aspect of the forearm. Resultant pain was scored by a visual analogue scale (VAS), and skin temperature change was analyzed by means of a computer-assisted infrared thermography. Intradermal melittin temporarily produced severe pain, followed by a sustained increase in skin temperature. The skin temperature increase peaked in about 10 min and outlasted 1 h. Topical application of 10% lidocaine gel did not significantly suppress the melittin-induced pain, but markedly suppressed both the increase in the peak temperature and the area of temperature increase. In conclusion, 5 mug of melittin is sufficient to produce pain in humans and 10% lidocaine gel differentially decreases the melittin -induced axon reflex without any significant analgesic effect.

During winter 1997, an apiary trial was conducted to test the effects of two different application methods and concentrations of dihydrate oxalic acid (OA) on varroosis control. Fifteen colonies of Apis mellifera ligustica Spin. placed in Dadant-Blatt standard hives were divided into 3 groups and submitted to the following treatments: 1) spray of 50 mL OA -water solution per hive (30g OA + 1000mL distilled water), 2) topical application of 50 mL OA- sucrose-water solution per hive (60g OA + 200g sucrose + 1000mL distilled water), 3) control (untreated hives). Four weekly treatments were applied in each group, being the first treatment without sealed brood. In order to evaluate mite infestation, adult bees were sampled from each hive before and after treatments. The sealed brood (worker and drone) was inspected at the end of the trial, and fallen mites were counted weekly. Treatment efficacy was expressed as "percent reduction of varroa infestation among adult bees" (DELTAI), "percent varroa mortality" (M), "percent infested worker pupae after the treatment period" (C), and "number of female adult mites per 30 drone cells" (D). The best result (82% +- 16.9 percent varroa mortality) was obtained by the spray treatment of oxalic acid in water solution. In general, for both treatments, the highest mite mortality coincided with the 1st treatment, applied with no sealed brood. After the 1st treatment, mite mortality was highest for sprayed oxalic acid, which was better distributed among the adult bees than syrup-based treatments. Oxalic acid content determined in honey samples taken from the nest after treatments did not differ significantly between treated and control hives.

In this work we studied the effect of Ca2+ on the ability of immobilized PLA2 to hydrolyze phospholipid substrates either in aggregate or monomeric forms. We use a kinetic methodology for the determination of dissociation constants of soluble and immobilized PLA2-Ca2+ complexes. This approach allows us to obtain the values of the dissociation constants of enzyme -Ca2+ (KX) and enzyme-Ca2+-substrate (K'X) complexes from the kinetic data obtained at different substrate and Ca2+ concentrations. Results using mixed micelles of phospholipid-Triton X-100 showed that, in most cases, productive complexes were destabilized by immobilization of PLA2. However, a correct analysis of the interaction must be independent of the classical modes of PLA2 action toward lipid surfaces. Thus, a substrate in monomeric form was also employed to analyze the effect of immobilization on hydrolysis rate in the absence of interfacial activation. Kinetic data showed that the immobilization affected severely the mode of PLA2 action. The kinetic data also suggested that immobilization promoted conformational alterations in the Ca2+-binding site, destabilizing the productive complex enzyme-Ca2+-phospholipid.

Waxes are important as building material and for the chemical communication of the honeybee Apis mellifera carnica. In this study chemometric tools were established for classifying the different waxes inside the hive. By using gas chromatography in combination with mass spectrometry, components of different types of waxes were analyzed. By considering different substance classes of waxes, discriminant function analyses revealed distinct subtypes of comb waxes and of cuticular waxes. It is shown that the aging of comb wax is in part a spontaneous physicochemical process due to differential volatilities of compound classes with different chain length ranges. On the other hand it is directly influenced by the bees by adding lipolytic enzymes to the comb wax. The data suggest that the varying cuticular wax and comb wax compositions could serve as cues for bees to recognize castes, sexes, or comb age.

The effectiveness of the antibiotic oxytetracycline hydrochloride) against the bacterium Melissococcus pluton, which causes European foulbrood in honey bees (Apis mellifera) was investigated in this study. The minimum inhibitory concentration of oxytetracycline hydrochloride for 104 M. pluton isolates cultured from samples of brood and honey collected from A. mellifera colonies in New South Wales, Victoria, South Australia and Tasmania was determined. The minimum inhibitory concentration was 1 mug/mL for 51 isolates, and 2 mug/mL for 53 isolates. These results indicate that, although oxytetracycline hydrochloride has been used exclusively for the past 22 years to treat European foulbrood, Australian isolates of M. pluton are still sensitive to this antibiotic.

Formic acid was applied against Acarapis woodi Rennie in Apis mellifera colonies through wick, impregnated filter paper and in petridish. The former two methods proved significantly better resulting in 85.2 and 90.0 per cent of the mite mortality respectively.

Two doses of amitraz viz, one and two strips/colony were tested against Tropilaelaps clarea and it was found that the latter dose was quite effective in eliminating T. clareae within 22 days during monsoon and post monsoon seasons. However in case of former dose, colonies became mite free in 27 and 29 days during these seasons. Amitraz at higher dose of two strips/colony had no adverse effect on the brood, bees or queens.

Field studies in southwestern Guatemala demonstrated that plastic strips impregnated with either amitraz or coumaphos controlled Varroa jacobsoni Oudemans in colonies of honey bees, Apis mellifera L. In the spring of 1997, four groups of 12 colonies each were given two plastic strips in the broodnest containing one of four concentrations of amitraz (5, 7.5, 10 or 12.5%). A fifth group was untreated. All four amitraz treatments were highly effective (97 to 99% mite mortality) in reducing numbers of varroa over a 47-day treatment period. In the fall of 1997, a similar study was done with coumaphos-impregnated plastic strips placed in the broodnest or attached to the hive entrance. Four groups of ten colonies each received treatment, and the remaining six colonies were untreated controls. Broodnest treatments were one, 10% strip; or two, 10% strips; or two, 1% strips per colony. Two 10% strips were attached to the hive entrance in the fourth group. One or two 10% strips were effective against varroa (91 -97% reduction) when placed in the broodnest or across the hive entrance. The 1% strips and controls were ineffective and failed to reduce the mite population.

In this study, we examined the role of cAMP-dependent protein kinase (PKA) in associative olfactory learning of the honeybee, Apis mellifera. In the bee, specific interference with molecules to clarify their role in a certain behavior is difficult, because genetic approaches, such as mutants or transgenic animals, are not feasible at the moment. As a new approach in insects in vivo, we report the use of short antisense oligonucleotides. We show that phosphorothioate-modified oligodeoxynucleotides complementary to the mRNA of a catalytic subunit of PKA directly injected into the bee brain cause a reversible and specific downregulation of both the amount of the catalytic subunit and of PKA activity by 10-15%. The amounts of the regulatory subunit of PKA, as well as PKC, are not affected. The slight "knockdown" of PKA activity during the training procedure, a classical olfactory conditioning of the proboscis extension reflex, neither affects acquisition nor memory retention 3 or 6 hr after training. However, it causes an impairment of longterm memory retention 24 hr after training. Downregulation of PKA 3 hr after training has no detectable effect on memory formation. We conclude that PKA contributes to the induction of a long-term memory 24 hr after training when activated during learning. Second, we demonstrate that the antisense technique is feasible in honeybees in vivo and provides a new and powerful tool for the study of the molecular basis of learning and memory formation in insects.

Mushroom bodies are central brain structures and essentially involved in insect olfactory learning. Within the mushroom bodies gamma-aminobutyric acid (GABA)-immunoreactive feedback neurons are the most prominent neuron group. The plasticity of inhibitory neural activity within the mushroom body was investigated by analyzing modulations of odor responses of feedback neurons during olfactory learning in vivo. In the honeybee, Apis mellifera, feedback neurons were intracellularly recorded at their neurites. They produced complex patterns of action potentials without experimental stimulation. Summating postsynaptic potentials indicate that their synaptic input region lies within the lobes. Odor and antennal sucrose stimuli evoked excitatory phasic-tonic responses. Individual neurons responded to various odors; responses of different neurons to the same odor were highly variable. Response modulations were determined by comparing odor responses of feedback neurons before and after one-trial olfactory conditioning or sensitisation. Shortly after pairing an odor stimulus with a sucrose reward, odor-induced spike activity of feedback neurons decreased. Repeated odor stimulations alone, equally spaced as in the conditioning experiment, did not affect the odor-induced excitation. A single sensitisation trial also did not alter odor responses. These findings indicate that the level of odor-induced inhibition within the mushroom bodies is specifically modulated by experience.

Viruses of the honey bee have been known for a long time; however, recently the attention of scientists and beekeepers has turned towards the relationship between these viruses and the parasitic mite V. jacobsoni. Although clinical symptoms indicated the presence of some of the viruses of bees in Hungary, none have previously been isolated or identified. During July unusual adult bee and brood mortality was observed in some colonies of an apiary in Budapest known to be infested with V. jacobsoni. Large amounts of acute paralysis virus (APV) were detected serologically in healthy honey bee pupae killed by the injection of a bacteria-free extract of diseased adult bees. Crystalline arrays of 30 nm particles were seen in ultra thin sections of the tissues of injected pupae and naturally infected adult bees. In spite of the application of acaricide treatments, the bee population in several colonies had collapsed by the end of summer and the apiary suffered severe wintering losses.

The analysis of phenotypic divergence among local populations within a species has been traditionally performed in a spatial context, although advances in genetic analysis using mtDNA have permitted a simultaneous evaluation of geographical and historical patterns of variation, so-called phylogeographical analysis. In this paper, we combine these two dimensions of variation (geographical space and phylogenetic history) to evaluate patterns of phenotypic evolution in honey bees (Apis mellifera L.). Data on 39 phenotypic traits, derived from 417 colonies grouped into 14 subspecies, were analysed using autocorrelation methods. Mantel tests indicated that the relationship between phenotypic divergence, estimated by Euclidean distances among subspecies' morphological centroids, was significant both when compared to geographical distance (r=0.371; P LGT 0.01) and to genetic distance (estimated as sequence divergence (%) in a mtDNA region encompassing part of the NADH dehydrogenase subunit 2 and isoleucine transfer RNA (r = 0.329; P LGT 0.01)). For the analysis of each trait, the effects of the geographical co-ordinates (latitude and longitude of subspecies geographical range) and of the phylogenetic patterns (defined by eigenvectors of the genetic distance matrix) on phenotypic variation were simultaneously analysed using an extension of a recently developed model, called Phylogenetic Eigenvector Regression (PVR). In general terms, the partial regression slopes indicated that the variation in the characters traditionally associated with adaptive processes, such as body and wing size, were better explained by geographical position. However, characters usually thought to be neutral, such as wing venation angle, were more associated with phylogeny. This is expected because PVR can be interpreted as a partition model, in which adaptive variation tends to be independent of phylogeny (and, in this case, associated with geography). In addition, the first principal component derived from the expected values of the model for each trait, which can be interpreted as the phenotypic variation predicted by phylogeny, is more structured in a north-south cline than are the original data, supporting an adaptive interpretation. The phylogeographical autocorrelation analyses performed in this study show that different traits are more related to one of the two dimensions of variation (geography and phylogeny), and these patterns can furnish insights into the nature of phenotypic evolution in these organisms.

Comparative studies conducted on the pollinating activities of Apis cerana indica F. and Apis mellifera L. revealed that the former spent 22.1 per cent more time per day in pollinating cauliflower bloom than the latter. Mean number of A. c. indica and A. mellifera visits per inflorescence per hour was 4.75 and 2.06, respectively. Mean duration of each blossom visit by pollen foraging, nectar foraging and nectar robbing A. c. indica was recorded as 5.14+-0.21, 6.34+-0.26 and 6.05+-0.24 seconds, respectively. The comparative statistics for A. mellifera were 6.62+-0.26, 7.37+-0.43 and 5.26+-0.25 seconds. Number of flowers visited per plant by A. c. indica or A. mellifera bees seeking pollen or robbing nectar were almost equal. However, A. c. indica bees gathering nectar visited 18.15+-1.10 flowers per plant as compared to 16.47+-0.64 flowers visited by A. mellifera. Depending upon the mean quantities of loose pollen carried on their bodies, the various worker groups comprised three statistically different categories as follows: pollen foraging A. mellifera RGT pollen foraging A. c. indica = nectar foraging A. mellifera = nectar foraging A. c. indica = nectar robbing A. mellifera and A. c. indica. On the basis of relative pollinating efficiency rating, both the species were equally good pollinators, the average rating obtained by A. mellifera being 3.1 as against 3.4 by A. c. indica.

Performance testing in honeybees relies on comparing colony traits of commercial interest in a 1- or 2-year test period. Groups of sister colonies are tested to determine breeding values and the procedure is gravely distorted if unrelated queens are included in the sister groups. Maternity was verified in nine sister queen groups from a routine performance test. Individual workers (n = 40) were taken from 36 queenright colonies and genotyped using four DNA microsatellites. Queen genotypes were derived from the worker offspring. The consistency of maternity of the sister queen groups was evaluated using the number of alleles per locus and the putative mother queen genotypes. One group unambiguously included non-sister queens. In our tested population, the probability of not detecting unrelated queens ranged from LGT 0.001 up to 0.005 depending on the putative mother queen genotype. In light of the high costs and labour of testing colony traits, we recommend including maternity testing into the routine procedure of honeybee performance testing.

Studies on Varroa jacobsoni population dynamics were conducted on 32 full -sized honeybee colonies of the Iberian bee race. The V. jacobsoni population growth followed an exponential model until it reached a collapse phase. In the experimental conditions this happened about 8 months to 1 year after chemical treatment. On average, the weekly intrinsic mite growth rates were very high, the yearly increases in mite population were 209 232-, 5 436-, 942- (with drone baiting) and 3 036 -fold. A modelling approach was developed to describe the mite intrinsic growth rate regarding a) an overall range, b) only growth phenomena or c) only decay phenomena. The probability of each mite finding a free larva on which to reproduce, the occurrence of mite immigration, and the mite death rate were the most significant variables to explain the mite intrinsic growth rate during the growth phase. The model had a good fit, R2 = 0.905, and good predictive performances, RPrediction2 = 0.896.

The steady chemical treatment against V. jacobsoni mites shows some essential problems: residuals of the drugs in the bee products and resistance of the mites to the active agents in the drugs. A method to control varrooosis without chemical treatments must be found. The best way to avoid problems created by chemical treatments is through selection for a higher tolerance to V. jacobsoni by the honey bees. A basic requirement to achieve this aim is the knowledge of population parameters for the tolerance to the mite. Considering that the reproductive biology of the honey bee deviates from that of other livestock species, heritabilities were estimated for tolerance to V. jacobsoni and for honey yield. Data were sampled from a total of 1 638 performance-tested colonies reared from 412 queens in the years 1988-1995. The queens belonged to the Institute of Bee Research in Lunz am See, Austria and private beekeepers of the breeding union, Austrian Carnica Association. Traits recorded were honey yield and tolerance to V. jacobsoni. As a general selection criterion for tolerance, the number of mites were counted on a special bottom board during the annual treatment with Apistan at the end of the testing season. Population parameters were estimated by an adapted half-sib analysis based on queens, using the restricted maximum likelihood (REML) methodology. The average relationship between two randomly chosen females (queens) was estimated as 0.38. The estimated heritability for honey yield was 0.20, which is documented by several other studies. The estimated heritability for tolerance to V. jacobsoni was 0.13 (table II). The phenotypic correlation between honey yield and tolerance to V. jacobsoni indicated a positive tendency (+0.17). The genetic correlation (-0.05) showed a very weak favourable direction, but owing to the standard deviation (0.24) it has to be interpreted very carefully. Further studies are necessary to analyse the genetic correlation between honey yield and varroa tolerance precisely. According to the results, selection response for tolerance to V. jacobsoni can be expected if performance testing and selection is carried out in large breeding populations.

Honey bee viruses in Apis mellifera colonies were studied at eight Nordic locations with disparate Varroa jacobsoni infestations. Cloudy wing virus (CWV) was the most prevalent infection in all apiaries irrespective of mite infestation. Detection of CWV was not associated with colony collapse in this study. In one apiary where colonies collapsed, deformed wing virus (DWV) was detected. When certain mite mortality levels were reached in this apiary, both live and dead bee samples were always positive for DWV. However, colonies with low values of mite mortality could also be positive for DWV, and this virus could be detected several weeks before colony death in some cases. In the second apiary with collapsing colonies acute paralysis virus (APV) was detected in a live bee sample from one colony, close to the time of colony collapse. The following viruses were detected for the first time in the respective countries, CWV: Denmark, Norway and Sweden; BQCV: Denmark; DWV: Sweden.

Newly emerged adult honey bees, Apis mellifera L., were fed with a pollen -based food containing various additives: purified and activated Cry1Ba delta-endotoxin, from Bacillus thuringiensis Bt4412 (Bt) (1, 0.25 and 0.025 % w/w), Bt biopesticide preparations, Dipel 2X (1 and 0.25%) and Foray 48B (0.25%), and Kunitz soybean trypsin inhibitor (SBTI) (1, 0.5 or 0.05 %). The bees received these foods for 7 days and were then given control food without additives for the rest of their lives. Bee survival time was unaffected, and the food was consumed at the same rate as control food for all treatments, except 1% Dipel, where both survival and food consumption were significantly reduced. A second experiment showed that bees completely deprived of the pollen-based food also had poorer survival than those fed with the control food. Adult bees are unlikely to be harmed by transgenic plants expressing Cry1Ba or SBTI, or by Bt biopesticides that are used as recommended.

A study was conducted in 1996 and 1997 to determine if honey bees, Apis mellifera L., could vector Bacillus thuringiensis Berliner variety kurstaki from hives equipped with a pathogen applicator to sunflower capitula and if the amount of B. thuringiensis deposited on the capitula would be sufficient to control the banded sunflower moth, Cochylis hospes Walsingham. The study demonstrated that honey bees became contaminated with B. thuringiensis as they exited hives equipped with filled pathogen applicators and deposited enough B. thuringiensis on the capitula to cause banded sunflower moth larval mortality. When 2 methods of applying B. thuringiensis were compared, the honey bee vectoring method gave better or equivalent control of the banded sunflower moth larvae than manual sprays, resulting in higher seed yields than manual sprays. The presence of honey bees also increased seed set which contributed to greater yield.

Two factors that influence age at onset of foraging in honeybees are juvenile hormone (JH) and colony age demography (older bees inhibit behavioral development of younger bees). We tested the hypothesis that genetic variation among bees for these factors influences genetic variation in behavioral development. Pairs of colonies showing genetic differences in rates of behavioral development were identified in a screening experiment and bees from these colonies were used for physiological and behavioral assays. Six pairs were assayed, three with European bees only and three with both European and Africanized bees. There was genetic variation for the following four components: (1) production of JH in four pairs (experiment 1); (2) sensitivity to JH in three pairs (experiment 2); (3) sensitivity to social inhibition in three pairs (experiment 3), and (4) potency of social inhibition in four pairs (experiment 4). Cross-fostering assays (experiment 5), which allowed all four components to be evaluated simultaneously, revealed genetic variation for production of JH, sensitivity to JH, or sensitivity to social inhibition in five of six pairs, and potency of social inhibition in five of six pairs. There was often evidence for genotypic differences in more than one component, and no consistent pattern of association among any of the components. Africanized bees had faster rates of behavioral development than European bees, but there were no racial differences in patterns of variation among the four components. These results indicate that there are at least several, apparently distinct, physiological processes associated with JH and colony age demography upon which natural selection can act to alter the rate of behavioral development in honeybees.

The 393bp nucleotide sequences of RNA polymerase genes in three isolates of Kashmir bee virus were compared. There was a 97.4% similarity between Canadian and U.S. isolates and an 80.4% or 81.2% similarity between the Australian strain and the two North American isolates. The amino acid sequence similarity between the two North American isolates was 99.2%. The similarities between the Australian isolate and Canadian and U.S. isolates were 97.7% and 96.9%, respectively. These three KBV isolates could also be differentiated by differences in the cleavage sites of the restriction endonuclease MaeII.

Major proteins of honeybee (Apis mellifera L.) royal jelly (RJ) are members of the MRJP protein family. The second most abundant protein of RJ is the protein named MRJP2. In this report we describe the isolation of MRJP2 by ion exchange column chromatography and its molecular characterization as well as the preparation of recombinant MRJP2 by heterologous expression in E. coli. The SDS-PAGE homogenous 49 kDa protein is composed of eight proteins with different isoelectric points in the range of 7.5 to 8.5 pH.

Insect juvenile hormone (JH) has been related to modulation of vitellogenin (Vg) synthesis, a protein produced by fat body cells, secreted in haemolymph and sequestered by developing oocytes. A stimulatory JH action has been described for the majority of species studied thus far. In some insects, however, Vg synthesis has been inhibited or unaffected by JH. The aim of this study was to re-examine the action of JH on Vg synthesis in Apis mellifera workers, since contrasting effects of this hormone were described. Newly emerged worker bees were treated with different doses of pyriproxyfen (PPN), a potent JH analogue. Vg and total protein were quantified in haemolymph samples of newly emerged up to 6-day-old worker bees. Protein synthesis activity of fat body cultured in vitro and ultrastructure of fat body cells were also examined. High doses (1.25, 2.5, 5 and 10 mug) of PPN inhibited the onset and accumulation of Vg in the haemolymph of young worker bees in a dose-dependent fashion. This inhibition was not a result of fat body cell degeneration or death, as illustrated by fat body cells ultrastructure analysis, but by impairing Vg synthesis, as demonstrated by in vitro culture of fat body cells. Low doses (0.001, 0.01 and 0.1 mug) neither affected the normal synthesis and secretion of Vg into the haemolymph nor caused an early onset of Vg in treated bees (which could be interpreted as a JH-activating effect), as shown by Vg quantification at 24-h intervals. The results suggest that a low JH titre in honey bee workers permits the onset and accumulation of Vg in haemolymph, whereas high JH levels turn off Vg synthesis.

In honeybees (Apis mellifera) laying worker offspring is rare. One mechanism to suppress worker reproduction is through worker policing, i.e. workers remove unfertilised eggs laid by other workers. This behaviour has been shown to be adaptive as soon as the queen performs polyandrous matings. The average relatedness to the queen's drones is higher than to the worker laid offspring. In the Cape honeybee (A. m. capensis) reproductive workers lay fertilised eggs which develop into females. In this case the average worker relatedness to sexual reproductives reared from worker or queen offspring is identical. Worker policing has been predicted by evolutionary theory to be less expressed in A. m. capensis colonies than in other honeybees. We found genetic evidence that worker policing is not common in the Cape honeybee. Laying worker offspring was identified in queen right colonies using microsatellite DNA analysis.

The antimutagenic effect of ethanolic extract of propolis (EEP) and honeybee (Apis mellifera) venom, both collected in the State of Sao Paulo, Brazil, was assessed by the Salmonella/microsome assay upon direct- and indirect-acting mutagens. EEP had inhibitory effect (in an ascending order) on the mutagenicity power of daunomycin (TA102), benzo(a)pyrene (TA100), and aflatoxin B1(TA98) and the venom acted against the mutagenicity of 4-nitro-o-phenylenediamine (TA98) and daunomycin (TA102).

Pollen traps were placed at the entrance of two hives located in Hinojos (Huelva, Spain), and pollen loads accumulating in the trap's collecting tray were collected four times along one day (6-III-1987). Twenty-two pollen types were found, most of them being collected by both colonies. Diplotaxis virgata, Oxalis pes-caprae, Raphanus raphanistrum and Halimium commutatum were the main pollen sources. Daily patterns of pollen collection from each species were different.

Thousands of individuals in a house-hunting honey bee swarm make a collective decision for one among many nest sites discovered. We recorded the dances on swarms in a forested area, where one swarm's search encompassed about 150 km2 and many different sites. We then analyzed swarms in a desert area with only nest sites that we provided and monitored, to study how the swarm winnows multiple finds to a single site over the course of a few days. Most bees did not visit any site, very few visited more than one. Apparently choices were made with little or no direct comparison, through the interaction of two mechanisms: positive feedback through recruitment leading to growth in the number of scouts visiting good nest sites, and attrition reducing activity and recruitment for non-chosen sites. Individual differences between bees substantially affected these dynamics. Scouts varied considerably in amount of dancing and persistence, but most that danced did so vigorously after their first few visits, and then dropped out, ceasing their dancing though continuing to visit the nest site. Dances were nearly twice as long as reported for nectar and pollen. Scouts followed dances of others, and occasionally visited alternative sites, but rarely switched their dancing. When unanimity is reached, the bees must recognize that a decision has been made, break up the swarm cluster, and fly to the nest site. Buzz-running (Schwirrlaufen) probably plays a role here, but we observed less buzz -running than previously reported, and this occurred even early in the process; it might function as a chain-reaction effect triggering the end of the house-hunting process. Our results suggest that the choice among nest sites relies less on direct comparison of nest sites, and more on inherent processes of positive feedback and attrition by dancers dropping out.

The effects of crotapotin (a non-toxic and non-enzymatic acid polypeptide naturally complexed with phospholipase A2) and heparin on rat paw edema induced by different secretory phospholipases A2 (sPLA2) have been investigated. The ability of crotapotin to affect the enzymatic activity of the sPLA2(s) have also been evaluated. Secretory PLA2(s) obtained from both snake (Naja naja, Naja mocambique mocambique, Crotalus adamanteus and Crotalus durissus terrificus) and bee (Apis mellifera) venoms as well as that from bovine pancreas were used in this study. Rat paw oedema was induced by a single subplantar injection of the sPLA2s (5-30 mug/paw) in absence and presence of either crotapotin (10-100 mug/paw) or heparin (50 U/paw). Paw volume was measured using a hydroplethysmometer. Phospholipase A2 from Naja naja, Naja mocambique mocambique, Apis mellifera venoms and the basic component of Crotalus durissus terrificus venom all induced dose -dependent rat paw oedema whereas those from Crotalus adamanteus venom and bovine pancreas were ineffective. Paw oedema induced by PLA2(s) from both Naja naja and Apis mellifera venoms was significantly (P LGT 0.05) inhibited by crotapotin (0.1-100 mug/site) whereas the Naja mocambique mocambique venom PLA2-induced oedema was significantly potentiated (P LGT 0.05) by this polypeptide (40 mug/site). On the other hand, heparin (50 U/paw) had no effect on the paw oedema induced by PLA2 from Naja naja and Apis mellifera venoms but significantly inhibited the Naja mocambique mocambique venom PLA2-induced oedema. The measurement of the in vitro phospholipasic activity revealed that crotapotin inhibited by 60-70% the enzymatic activities of PLA2(s) from Crotalus adamanteus, Naja mocambique mocambique, Apis mellifera venoms and bovine pancreas. Our results suggest that despite the great homology between the various types of sPLA2 they interact with crotapotin on cell surfaces in different ways leading to either inhibition or potentiation of the paw oedema by a mechanism unrelated to their enzymatic activities. Since heparin reduced paw oedema induced by PLA2 from Naja mocambique mocambique venom it is likely that this sPLA2 is similar to the novel heparin-sensitive PLA2 found in mast cells.

The requeening process was investigated under emergency conditions in honey bee colonies (Apis mellifera L.). The progression of queen cell construction was closely monitored after removal of the mother queen, and the newly-emerged queens were measured for several physical traits to quantify their reproductive potential (= quality). The results suggest that workers regulate the queen rearing process by differentially constructing cells. Workers built different numbers of queens cells from different ages of brood and non-randomly destroyed over half (53%) of the initiated cells before their emergence. For those queens whose cells were not torn down, the variation in reproductive quality was limited, varying only slightly among age groups for queen size. Several hypotheses are discussed which might explain the adaptive benefit of worker regulation during queen rearing.

We investigated absconding frequency and latency in queenright and queenless honeybee colonies in thelytokous Apis mellifera capensis, arrhenotokous Apis mellifera scutellata and their natural thelytokous hybrids. There was no significant difference in frequency of absconding among any of the queenright colonies. Absconding was significantly greater in thelytokous queenless colonies than in the queenless arrhenotokous ones. Latency to absconding did not differ among the three groups of queenright colonies nor between the queenright and queenless colonies of A. m. capensis and A. m. scutellata. There were significant differences in latency between queenright and queenless hybrids and significant differences in latency among the three groups of queenless colonies. Among queenless colonies, A. m. capensis absconded twice as readily as did A. m. scutellata and the hybrids were intermediate. Afterabsconding events include the fates of the absconding colony as well as nestmates left behind. One group of orphaned nestmates of A. m. capensis amalgamated with another queenright colony. In the case of A. m. scutellata either drones were produced or the residual queenless colony was joined by a queenless thelytokous group, subsequently reared a queen and then absconded. Differences in the rate and degree of ovarial development indicate that queenless thelytokous workers have the physiological capacity for reproduction, a trait that contributes to colony fitness.

We investigated pollen and nectar foraging of honey bees, Apis mellifera L., from pollen-poor and pollen-rich, small and large colonies in blooming highbush blueberry, Vaccinium corymbosum L. cv. Bluecrop fields. The proportion of pollen foragers differed significantly between pollen-rich and pollen-poor colonies after storage levels were manipulated, but foraging and pollen stores returned to similar levels within a week. No differences were found in small colonies, although the proportion of pollen foragers was high (46% and 45% from pollen-rich and pollen-poor colonies, respectively). Only 7.6% of pollen foragers carried Vaccinium sp. pollen in their loads independent of treatment, day, and colony size, whereas 60.8% of nectar foragers carried up to 100 tetrads of Vaccinium sp. pollen on their bodies. The average proportion of Vaccinium sp. pollen carried by nectar and pollen foragers per day and treatment was less than 10%. Our research indicates that when colonies are placed in fields of blooming blueberry flowers, pollen foraging is stimulated in large colonies with stores that are pollen poor, but predominantly for pollen types other than blueberry. This research indicates that nectar foragers are the major visitor of highbush blueberry cv. Bluecrop and suggests that increasing the number of nectar foragers rather than pollen foragers would result in more honey bees foraging on highbush blueberry, in particular cv. Bluecrop.

Multivariate morphometric analyses were performed on measurements of nine characteristics of 4011 worker bees from natural populations of the Drakensberg mountains and surrounding areas in southern Africa between 28degree and 34degree S latitude and 25degree and 31degree E longitude. A discriminant function analysis yielded three morphoclusters: group 1 comprising an unnamed population at higher than 1500 m altitude in the mountains; group 2 consisting of bees considered to be A. m. scutellata X A. m. capensis hybrids, and group 3 consisting of A. m. scutellata surrounding the mountains at lower (less than 1500 m) altitudes. The bees of group 1 show size similarities to disjunct populations of other large Afromontane bees, A. m. monticola. Group 2 hybrid bees occur in an area of marked climatic variability and manifest significantly high variances in their morphometrics, pheromones and DNA characteristics. It is suggested that differences in swarming seasons among these populations effectively cause temporal reproductive isolation between the group 1 mountain bees and those A. m. scutellata below the escarpment.

This research was designed to determine economic thresholds for Varroa jacobsoni mites in mature overwintered colonies under conditions that encourage or discourage mite immigration. Congruent data from the present study and our earlier work suggest that a true late-season (August) economic threshold for mites in the southeastern USA lies within a range of mite populations of 3 172-4 261, ether roll mite levels of 15-38, and overnight bottom board insert mite levels of 59-187 in colonies with bee populations of 24 808-33 699. Overwintering colonies can benefit from an additional early-season (February) treatment. This benefit was realized in colonies which in February had the following average values: mite populations 7-97, ether roll 0.4-2.8, bottom board inserts 0.6-10.2 and bee populations 12 606-13 500. Continuous acaricide treatment never achieved colony bee populations or brood number significantly higher than in colonies treated more conservatively. There is evidence that minimizing mite immigration has the benefit of delaying the onset of economic thresholds.

The immunohistochemical localization of the heat shock proteins (Hsp70 and Hsp90) and histone protein in healthy and Paenibacillus larvae infected honeybee (Apis mellifera L.) larvae has been studied. Hsp70 was found in the nuclei and the cytoplasm of infected midgut, salivary gland cells and haemocytes, but not in uninfected larvae. Hsp90 was localized in both infected and uninfected cells. Exposed histone proteins were localized in the nuclei of dying uninfected cells undergoing programmed cell death. The distribution of histone protein in uninfected cells of midgut, salivary gland, and other tissues was nuclear and indicative of normal programmed cell death at levels between 1 and 5%. After applying histone protein antibodies to P. larvae infected honeybee larvae, the DAB based reaction product was located in the nuclei or immediate surroundings of all larval cells. The Hsp70, Hsp90 and histone protein distribution patterns are discussed in relation to the morphological, cytochemical and immunocytochemical characteristics of programmed cell death and pathological necrosis. Results produced by methyl green-pyronin staining confirm an elevation of RNA levels in normal programmed cell death and a reduced staining for RNA in necrotic infected cells.

Responses of New Zealand bees from Italian (Apis mellifera ligustica) and dark (Apis mellifera mellifera) races to infection with Nosema apis were compared. Newly emerged adults from five colonies of Italian bees and three colonies of dark bees were tagged, dosed individually with N. apis spores and placed in cages with undosed companion bees from the same colony. Dosed individuals were removed and examined at different times to measure progress of infection. At the end of the experiment, companion bees were examined to determine the spread of infection from dosed to undosed bees. There were no significant differences between the two races in either of these measures of response to N. apis. Bees from the different colonies were pooled according to race, and their responses (percentage infection and longevity of infected bees) to a range of doses of N. apis spores determined. These data also showed no significant differences due to race.

Hygienic behavior in honey bees can be tested by piercing the brood with a pin; however, there is concern that variability in the quantity of fluids that leaks from the pupae could influence test results. Colonies of Apis mellifera carnica were tested to evaluate this possibility. We made four repetitions of four treatments and one control in each of three colonies. The order of degree of hygienic behavior was: pin-killed capped worker brood with a drop of body fluid injected underneath the cell capping RGT pin -killed capped worker brood RGT undamaged capped brood with a drop of body fluid injected underneath the cell capping RGT control or a drop of pupal body fluid placed on the cell cappings. All of the differences were significant (Tukey test, P LGT 0.05) except the body fluid on the cell cap, which gave the same results as the control. The addition, inside worker brood cells, of pupal body fluid had a significant effect on honey bee hygienic behavior, both in normal brood and in pin-killed brood.

The small hive beetle, Aethina tumida Murray, is a nitidulid species newly recorded attacking honey bees in the Western Hemisphere. We initiated field and laboratory tests on the control and biology of this new pest. Very high mortality of adult and larval A. tumida in Florida and Georgia hives resulted from field tests using 10 % coumaphos in plastic strips in trapping devices on the hive bottom: as high as 90.2 % beetle mortality occurred in hives in Florida. Adult beetles were found in the laboratory to feed on honey bee eggs, completely consuming all eggs, even in the presence of honey and pollen. Odors from hive products plus adult bees were found to be significantly attractive to flying adult beetles, as evidenced in baited trap studies. Hive products alone or bees alone were not attractive to adult A. tumida.

For more than 20 years there has been conflict arising from different points of view concerning the role of the introduced honeybee. There is a strong prima facie argument, and some supporting evidence, that introduced honeybees are likely to adversely affect the environment. Some land management agencies have consequently adopted a policy of removal of hive honeybees from areas devoted primarily to conservation. On the other hand, some argue that the scientific evidence on the issue remains poor, point out the economic benefits that arise from the honeybee industry and suggest that removal of apiaries from such areas is unjustified. It is suggested in this paper that adoption of the Precautionary Principle could significantly reduce this conflict. Instead of the focus being on obtaining definitive "proof" concerning possible impacts of honeybees, it could shift to finding ways to reduce the density of feral honeybees, and hence their impacts on both the natural environment and honeybees in hives. The focus could also shift to finding sites where reduction in honeybee density is feasible and the likely conservation gains arising from such a reduction are relatively high. In this way both the honeybee industry and the natural environment could benefit.

In S. postica the hypopharyngeal glands are present in workers, males and queens. The glands of newly emerged workers are in a prefunctional phase, in nurse workers they reach their highest development and in forager workers they suffer reabsorption. The newly emerged males and queens, however, have well developed glands that soon start involution. The electrophoretical pattern of worker and male hypopharyngeal glands is compared with the pattern of nurse workers of A. mellifera. The results show simularities, as well as differences among the S. postica males and workers, and among the phases of worker life. The electrophoretic band pattern suggests that the hypopharyngeal glands of nurse workers of S. postica produce substances similar to the ones produced by A. mellifera. The similarity of the extracts of nurse glands of A. mellifera and S. postica, as well as the behavioural similarities of the workers, suggest the same function of this gland in both species.

Seven new p-coumaric acid derivatives along with seventeen known compounds, including four flavonoids, one prenylated phenolic acid, four diterpenoic acids, one lignan, two p-coumaric acid esters and five cinnamic acid derivatives, were isolated from the ethyl acetate soluble fraction of 75% ethanol extract of Brazilian propolis. New compounds were elucidated as (E)-2,3-dihydroconiferyl p-coumarate, (E)-3-(2,3-dihydro-2-(2-((E)-p -coumaroyloxy)-1-methylethyl)-5-benzofuranyl)-2-propenoic acid, (E)-4-(2,3 -dihydrocinnamoyloxy)cinnamic acid, (E)-3-(2,2-dimethyl-3,4-dihydro-3 -hydroxy-2H-1-benzopyran-6-yl)-2-propenoic acid, (E)-3-(2,3-dihydro-2-(1 -methylethenyl)-5-benzofuranyl)-2-propenoic acid, (E)-3-(2,3-dihydro-2-(1 -methylethenyl)-7-prenyl-5-benzofuranyl)-2-propenoic acid and (E)-3-(3 -((E)-4-(2,3-dihydrocinnamoyloxy)-3-methyl-2-butenyl)-4-hydroxy-5 -prenylphenyl)-2-propenoic acid, on the basis of spectral evidence and chemical reaction. Five compounds: dihydrokaempferol (aromadendrin), 6 -methoxykaempferol, 4-hydroxy-3-prenylbenzoic acid, plicatin B and capillartemisin A, were isolated from propolis for the first time.

Economics of rice-poultry-duckery-fish-apiary-mushroom system under lowland conditions in Orissa was studied from 1992 to 1994. The results revealed that a net profit of Rs. 12,038 per year was obtained in rice-poultry -duckery-fish-apiary-mushroom Integrated Farming System (IFS) in 1.0 ha area. Conventional Cropping System (CCS) with rice-rice-pulses/maize gave a net income of Rs. 3450 per year from the same area. By inclusion of poultry-duckery-fish-apiary-mushroom components in IFS, the net income per day has been increased to Rs. 32.97 as against Rs. 9.42 in CCS.