Apidologie最新文献

Bee populations are declining due to agricultural expansion, habitat loss, and diseases such as nosemosis caused by microsporidian Vairimorpha spp. We evaluate how agricultural intensification affects the abundance of wild (Augochloropsis spp.) and managed (Apis mellifera) bees and how landscape modification impacts bee health quality by altering their susceptibility to be infected by Vairimorpha spp. Bees were collected using pan traps in nine fields with varying management intensities from Argentina, while landscape management intensity was assessed using satellite imagery for each field. We found the abundance of one wild bee species increases as the proportion of landscapes with low intensity management increases. Vairimorpha spores were only found in managed bees. We also found that prevalence of Vairimorpha increases as the proportion of intensive management increases. Our results suggest that agricultural intensification negatively impacts the abundance of wild bee populations and makes managed bees more susceptible to Vairimorpha spp. infection.

Stingless bee hives are commonly managed in the global tropics and subtropics. However, current monitoring methods for these hives are invasive and subjective, relying on manual assessments conducted by beekeepers. This approach may harm bees and, if performed by non-specialists, can lead to the death of key reproducing individuals: the mother queens. These queens are vital for maintaining hive health, as their absence can lead to colony death. Our study is aimed at exploring the potential of three hive indicators: temperature, humidity, and sound, as predictive factors for discerning the presence or absence of a mother queen in Tetragonisca fiebrigi hives. To do this, we collected data on these variables from six hives, including three queenless hives and three queenright hives, monitored over four consecutive days. Temperature and humidity were recorded every 15 min during this period, and 15-min audio recordings were made each day. We then employed five machine learning algorithms (extreme learning machine, K-nearest neighbors, multilayer perceptron, random forest, and support vector machine) to classify the data. Our findings revealed that all tested algorithms consistently achieved accuracy rates exceeding 90%, whether using acoustic or microclimatic variables. However, the highest accuracy was achieved with the microclimatic dataset. This approach holds great potential for reducing the damages caused by manual inspections while also enabling faster and more precise identification of the health of beehives. By implementing remote monitoring systems based on these indicators, beekeepers can benefit from improved efficiency and accuracy in assessing hive conditions.

Bumblebees (Apidae: Bombus) are abundant pollinators in Mediterranean habitats; however, interaction networks with plants have not yet been investigated in large areas of Italy, including its islands. Here, we analyzed plant-bumblebee networks through seasonal transects in a suburban park and a nature reserve of Eastern Sicily. After molecular and morphological identification of bumblebees, we built bipartite networks extracting complementarity, niche overlap, modularity and nestedness. In total, we sampled 10 of the 15 species of Bombus known from Sicily. Richness was close to that predicted by accumulation curves, and no differences in community diversity were found between the two sites. At both sites, the networks were not nested, highly specialized and modular, with high complementarity and low niche overlap, again with no differences between sites. In both sites, species-level specialization varied considerably and was independent from sample size. The network topologies suggest a possible role of local interspecific competition and/or of interspecific morphological variation among generalist bumblebees. Comparison of previously published data revealed that networks in Mediterranean areas are more specialized than those with a continental climate. This suggests the possibility of increased competition and/or phenotypic variation under harsh Mediterranean conditions. The vulnerability of the Mediterranean basin to droughts caused by climate change calls for detailed studies on pollinator-plant networks for conservation plans.

The environment in which pollinators are reared may influence both their health and pollination performance. We compared the performance of 12 colonies of bumblebees (Bombus terrestris), each in their own simple (tomato monoculture) or florally diverse (tomatoes, borage, and lavender) arena inside a glasshouse. We found that colonies reared in florally diverse environments had a higher proportion of foragers overall and maintained slightly higher and less variable relative humidity inside the nest. Moreover, adding floral resources to a tomato crop resulted in increased total crop yield, whereas individual tomatoes reared in the simple monoculture environment were larger than those in the diverse. These results provide an important step in understanding the extent to which bumblebee health and flower-visiting behavior are influenced by the complexity of the foraging environment and how a diverse floral environment may enhance pollinator behavior toward a focal crop.

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.