Apidologie最新文献

Viruses occupy a large proportion of the pathogen communities within honey bee colonies, with more than 80 species detected in Apis mellifera. Honey bee viruses are globally distributed and several species have been linked to honey bee diseases that threaten colony health. However, less is known about the ecology and epidemiology of viruses within honey bee colonies, and in particular whether a link exists between virus temporal dynamics and seasonal variations and/or colony dynamics. Using a large-scale longitudinal survey conducted over three years, we report the prevalence and abundance of deformed wing virus, acute bee paralysis virus, black queen cell virus, chronic bee paralysis virus and sacbrood virus (DWV, ABPV complex, BQCV, CBPV and SBV) in more than 300 colonies located in two different environments of southern Europe (Provence in France, Piemonte in Italy), and exhibiting contrasted climatic conditions. Monthly measurements performed throughout the beekeeping seasons indicate distinct seasonal trends in prevalence and abundance of the five virus species: DWV, SBV and ABPV complex displayed marked seasonal variations, that were similar in both environments tested. We also highlight the link between seasonal virus dynamics and colony dynamics for SBV/BQCV, and parasite dynamics for DWV. This study improves our understanding of virus ecology within honey bee colonies.

The analysis of morphology and body asymmetry in organisms can reveal the challenges faced during development. Populations of Varroa destructor exhibit morphological plasticity, but there is a lack of standardization in body structures and measurements used in research. This study aimed to identify, through geometric morphometrics, a body structure that allows for a standardized study of the morphological variations and fluctuating asymmetry of V. destructor in different environmental contexts. To this end, we analyzed the morphology of mites infesting colonies of Africanized honeybees in two contexts: different levels of hygienic behavior in the colonies and distinct environments (Caatinga and Atlantic Forest). Asymmetry is specifically assessed in the context of these environments. In colonies with differentiated hygienic behaviors, the metapodal shield showed a higher classification rate between groups (70%) than the genitoventral shield (64%), and it was the only structure that showed significant size differences between groups (p < 0.001). In mites from different geographic regions, the metapodal shield also exhibited a higher classification rate (78%) than the genitoventral shield (65%), with no significant difference in the size of the shields between the mite populations. Significant differences in fluctuating asymmetry were observed in the shape and size (p < 0.001) of the pair of metapodal shields and the shape of the genitoventral shield (p < 0.001). The results provide important methodological and ecological insights, highlighting the metapodal shield as a reliable structure for assessing shape, size, and fluctuating asymmetry. This standardization can improve consistency across studies and parasite monitoring.

Varroa destructor is the main sanitary problem for honey bee populations worldwide. Current synthetic acaricides used to control the mite’s infestations have drawbacks such as negative effects on bee health, residues in hive products, and mite resistance development. As an alternative, the natural compound oxalic acid (OA) has shown acaricidal properties and commercial products are now available on the market. This study aimed to evaluate the efficacy of OA and glycerin in cellulose strips for V. destructor control, considering factors like dose, method of administration, colony development stage, and initial mite infestation levels. The research also analyzed OA residues and the main honey quality parameters during the nectar flow period. Field experiments conducted in different seasons suggested that the use of OA and glycerin in cellulose strips is an excellent strategy for V. destructor control. Its efficacy depends on the time of the year it is applied, the dose, and the method of administration. In addition, its use does not affect the quality parameters of the honey. Considering the negative impact of V. destructor on honey bee colonies and the urgent need of alternative control strategies to synthetic acaricides, the results obtained in this study demonstrate that this product is a promising tool for controlling V. destructor.

Though many wild bee species nest in the ground, little is known of their potential exposure to pesticide residues in soil, or the effects of such exposure. Here, we introduce Anthophora plumipes as a potential model ground-nesting solitary bee species for controlled exposure to pesticides through soil. Bees from a naturally occurring population were allowed to nest in loam blocks containing varying concentrations of the neonicotinoid imidacloprid. Measured residues of imidacloprid in brood provisions and in bee bodies remained at < 0.01% of the concentration in surrounding soil, suggesting limited migration of contaminants from soil to brood. Furthermore, imidacloprid contamination had no marked effect on the number, survival, body size or rate of parasitism of offspring at the tested concentrations (≤ 10 mg/kg). This species native to Eurasia and North Africa may be a suitable model for further research on the ecotoxicology of ground-nesting solitary bee species.

In recent years, bumblebees have increasingly been used to study various aspects of bee biology, ecology and evolution. They are now broadly accepted as tractable model species, complementary to the domestic honey bees, for fundamental and applied apidology. Here, we provide a brief history of how bumblebee research developed since their domestication and commercialisation for crop pollination in the 1990s. Bumblebees are large social bees that can be kept and trained in the lab year-round. They are easy to manipulate and track individually in their small colonies. These practical advantages have offered new possibilities for experimental bee research, leading to major breakthroughs in different fields such as cognition, navigation, nutrition, host-parasite interactions, and insect declines. Many of these findings have later been confirmed in honey bees and other pollinators. We discuss some exciting directions for future apidology research based on bumblebees.

Oxytrigona tataira Smith (Trans Ent Soc Lond 11:497–512, 1863) was considered by different taxonomists to be a species with complex taxonomy, a dubious status and in need of taxonomic reevaluation. Furthermore, it has Oxytrigona cagafogo Müller (Nature 10:31–32, 1874) as its junior synonym, although there is no evidence to support such a decision. In this study, we used an integrative approach combining morphological data, geometric morphometric analysis of wings, and ecological niche overlap analysis to elucidate the true identity of O. tataira. For the morphological study, 923 specimens and the lectotype of Trigona tataira (= O. tataira) were examined, 470 wings were used for geometric morphometry, and 106 unique occurrence records were used for niche overlap analysis. In the morphological study, three species/morphospecies were identified: morphospecies 1 (morphologically corresponding to O. tataira), morphospecies 2 (morphologically corresponding to O. cagafogo), and morphospecies 3 (a new species for the genus). The geometric morphometry of the wings corroborated the results of the morphological study. The ecological niche overlap analysis, despite indicating a small niche overlap between O. tataira and O. cagafogo, also corroborated the results of the morphological and morphometric studies. Thus, our results confirmed the hypothesis that O. tataira and O. cagafogo are distinct taxonomic entities; therefore, we propose the revalidation of the taxonomic status of O. cagafogo Müller (Nature 10:31–32, 1874) status nov. Furthermore, it was still possible to identify and delimit a new species for Oxytrigona, which has already been described and will soon be formally published.

In temperate regions, the overwintering success of honey bee colonies, Apis mellifera, depends on the last generations of long-lived bees emerging in autumn, known as winter bees. While the physiological qualities of winter bees and their extended lifespan are well documented, yet literature on their flight activity performance is scarce. Here we studied the flight activity of long-lived winter honey bees and compared their performance with short-lived bees. Using radio frequency identification (RFID), we automatically monitored the number of flights, the total flight duration and the lifespan of 523 honey bees that emerged over the course of a year, including short-lived bees from spring, summer and autumn, and long-lived winter bees. We found that flight activity performance of short-lived bees decreased progressively from spring to autumn for both the number of flights and the total flight duration. Furthermore, we confirm that only a fraction of the bees emerging before winter are long-lived winter bees, with a lifespan of 143.5 ± 23.5 days (mean ± SD). With an average of 37.5 ± 44.2 flights and 12.7 ± 15.5 h of flight, we found that long-lived winter bees were substantially more active than summer and autumn short-lived bees, but performed similar activity than spring short-lived bees. We also found that a small proportion of long-lived winter bees participate in the vast majority of the flight activity of the colony. Our results suggest that the extended lifespan of long-lived winter bees does not affect their flight activity performance, probably explained by their physiological qualities.

The recent increase in mortality rates amongst honey bee colonies is a cause for concern. Assessing DNA damage in reproductive cells is crucial for species survival. This study aims to evaluate the potential of the sperm comet assay as a tool for in situ assessment of the genotoxic impact on honey bee populations with established high mortality rates. Previous studies have identified the presence of pesticide residues in bees and food stocks within the hives, indicating the existence of genotoxic agents in the localities under investigation. The values of comet assay parameters, namely Tail Intensity (TI%) and Olive Tail Moment (OTM, µm), scored in the sperm cells, increased following the mortality trend of the honey bee populations under study, providing evidence of significant DNA damage occurring during spermatogenesis. The alkaline comet assay in hemolymph confirmed the genotoxic effects observed in the sperm comet assay. The current study demonstrated for the first time that the sperm comet assay could serve as a reliable novel method for assessing genotoxicity in A. mellifera.

Eusociality in honeybees (Apis mellifera) is characterised by a reproductive division of labour, where the queen monopolises reproduction while worker reproduction is constrained. This constraint is mediated by queen mandibular pheromone (QMP), which inhibits worker ovary development through Notch signalling and possibly oocyte apoptosis. Dopamine has been implicated in regulating reproduction in worker honeybees, with prior studies suggesting that dietary dopamine enhances ovary activity in queen-less workers. This study aimed to test whether dopamine supplementation could overcome QMP-mediated reproductive constraint in worker honeybees. Using caged honeybee experiments, we administered dopamine and its precursor L-dopa at a range of concentrations, both in the presence and absence of QMP. Results showed that neither dopamine nor L-dopa supplementation affected ovary development, survival rates, or food intake, which contrasts with a previous study. These findings suggest that dopamine may not be a major factor in QMP-mediated reproductive inhibition. Instead, we suggest that the multifaceted nature of QMP’s components together with the complexity of neuroendocrine signalling makes it likely that multiple redundant mechanisms regulate worker reproduction. Future research should investigate the interplay between nutrition, dopamine and QMP components to fully understand the regulation of ovary activation in honeybee workers.