Amitraz is used by beekeepers to control Varroa destructor infestations within their colonies worldwide. Evidence for resistant mites continues to be reported and could be a major factor in widespread colony losses. Over 2 years, we investigated a diagnostic bioassay that tested our mites for susceptibility to amitraz. After diagnosing mites with the bioassay, we genotyped the mites searching for the Y215H mutation of the β2-octopamine receptor. We found that the diagnostic bioassay accurately predicted the resistant genotype 94.6% of the time, and it accurately predicted the susceptible genotype in 66.8% of mites. Additionally, we performed a standard treatment with the product Apivar® (active ingredient amitraz 3.33%) on the source colonies of these mites. Colonies receiving the Apivar® treatment (n = 32) were categorized by the expected efficacy of amitraz on their mites, and a group of colonies was designated as untreated controls (n = 12). Both high and low expected efficacy groups had significantly reduced mite infestations by the end of the treatment period (reduced by 98.2%) compared with control colonies, which did not have a significant change in mite numbers over the same period (reduced by 23.0%). The diagnostic bioassay was a strong predictor of the resistant genotype of V. destructor, but it was not an accurate predictor of field-level amitraz efficacy.
Honey bee (Apis mellifera) populations face increasing threats from pathogens, parasites, and synergistic interactions among pathogens and stressors that contribute to colony losses. Traditional hive health monitoring relies on visual inspections, mite counts, and targeted diagnostics, which are labor-intensive, expertise-dependent, and often detect infections only at advanced stages. Next-generation sequencing (NGS), specifically 16S rRNA gene and ITS amplicon sequencing, offers a powerful culture-independent approach for simultaneous detection of bacterial and fungal microbes in beehive samples (larvae, honey, bee tissue). This technology is particularly relevant for exotic pet medicine, where veterinarians may be consulted by beekeepers to investigate brood diseases in managed honey bee colonies. This paper reviews the application of 16S rRNA gene amplicon sequencing in apiculture and presents clinical case studies demonstrating its diagnostic utility. Longitudinal monitoring of brood nest samples revealed dynamic changes in Melissococcus plutonius abundance. In other cases, 16S rRNA gene amplicon sequencing excluded suspected European foulbrood (EFB) and documented co-infections involving agents such as Enterococcus faecalis and Paenibacillus dendritiformis (the latter representing the first reported detection in honey bee colonies in the U.S.). These findings highlight the ability of 16S rRNA gene amplicon sequencing to detect bacterial pathogens, reveal microbial community shifts, and differentiate primary from secondary microbes when combined with clinical context. 16S rRNA gene amplicon sequencing can support early intervention and avoidance of unnecessary antibiotics amid rising resistance concerns. By equipping exotic pet veterinarians with these tools, this approach enhances diagnostic accuracy for bee-related consultations, supports antimicrobial stewardship, and contributes to the welfare of pollinators as part of broader exotic animal practice. Despite challenges including cost, bioinformatics requirements, sample processing, and interpretation of complex datasets, 16S rRNA gene amplicon sequencing integration into routine apicultural practice shows promise for improved colony resilience and reduced losses.
Although supplemental feeding during dearth periods is widely practiced in developed apicultural systems, its adoption in Ethiopia remains limited due to the lack of affordable, nutritionally balanced, and locally adaptable feed formulations, as well as insufficient evidence on their comparative effectiveness under local conditions. This study evaluated the effects of nutritional supplementation on brood development, colony population growth, and honey yield of A. mellifera in Central Ethiopia. Four feeding treatments were tested: (1) Expeller pressed soybean cake flour (EPSCF) diet, (2) Niger seed cake flour (NSCF) diet, (3) Mung bean flour (MBF) diet, and (4) a control consisting of sucrose syrup. Colonies received 250 g of formulated diets or 1 L of syrup weekly. Feed consumption ranged from 80 g (NSCF) to 125 g (EPSCF), while control colonies consumed all syrup provided. Honey yield differed significantly among colonies receiving different diets (p < 0.05). Colonies supplied with the EPSCF diet produced the highest mean honey yield (14.75 ± 0.565 Kg/colony), indicating superior colony productivity, whereas MBF resulted in the lowest yield (8.12 ± 0.864 Kg/colony). Overall, EPSCF consistently outperformed other treatments across all measured parameters and generated the highest economic return (ROI = 240.39%). These findings demonstrate that EPSCF is a cost-effective and nutritionally efficient pollen substitute for improving colony productivity and profitability under Central Ethiopian conditions. Therefore, the use of EPSCF is recommended for smallholder beekeepers as a practical and affordable feeding strategy to enhance colony performance during dearth periods.
IntroductionCoffee production depends heavily on pollination services, but the combined effects of managed pollinators and pesticide use on crop yield and pollinator health are still poorly understood. This study evaluated the contribution of supplemental pollination by the stingless bee Scaptotrigona depilis to coffee yield and assessed the impact of thiamethoxam, a neonicotinoid insecticide, on colony strength in Brazilian coffee farms.MethodsColonies of S. depilis were introduced into both conventional and organic coffee farms. Coffee yield was measured in branches located near and far from bee colonies. Colony strength parameters were monitored over time, and pesticide residues were quantified in plant tissues (leaves, nectar, pollen) and in bee-collected floral resources.ResultsSupplemental pollination by S. depilis significantly increased coffee yield by 67% in branches closer to the colonies. Low but detectable residues of thiamethoxam and its metabolite clothianidin were found in plant tissues and bee-collected resources. No significant negative effects were observed on brood production or brood mortality in colonies located in conventional farms compared to those in organic farms. Foraging activity differed between farm types before exposure to coffee bloom but normalized over time.DiscussionManaged stingless bees can markedly enhance coffee production without experiencing measurable detrimental effects under current label-compliant neonicotinoid use. These findings offer practical insights for developing more sustainable coffee production strategies that align productivity with pollinator health and conservation.
Neonicotinoids are systemic insecticides used in agriculture to control herbivorous pests by targeting the nervous system. However, the persistence and presence of neonicotinoids in pollen and nectar raises concerns regarding impacts on non-target organisms, particularly pollinators such as bees. Bumblebees (Bombus spp.) are essential for wild plant pollination and crop production but are vulnerable to insecticides due to their foraging behaviors and ecological traits. While commercially available forms of neonicotinoids have been banned in select countries over recent years, they are still utilized extensively in many parts of the world, with limited understanding of impacts on bumblebee physiology and behavior. To investigate neonicotinoid effects on bumblebees, we systematically reviewed studies from Scopus and Web of Science following PRISMA 2020 guidelines. A total of 52 primary studies were identified, revealing a pronounced geographic bias, with 81% of research conducted in the UK and the U.S. (54% and 27%, respectively). Bombus terrestris, B. terrestris audax, and B. impatiens emerged as the most studied species whereas imidacloprid, thiamethoxam, and clothianidin were the most common neonicotinoid compounds tested, represented in 88% of the studies. In comparison, only a single study performed on B. ephippiatus and there are currently no published studies assessing the impact of the compounds nitenpyram or dinotefuran on bumblebee health and behavior. Behavioral alterations, particularly foraging and cognition, were the most prevalent reported effects of neonicotinoids, followed by reproductive health and physiological impacts. This review highlights the need for more geographically and taxonomically diverse research, particularly in regions still using neonicotinoids. The prevalence of sublethal effects raises concerns for colony health and pollination services, yet direct assessments of pollination efficiency remain limited. As such, critical knowledge gaps remain, particularly regarding understudied neonicotinoid compounds and bumblebee species, emphasizing the need for further research to inform sustainable agricultural practices and conservation strategies.
Beekeeping production in Africa is important for economic development, food security, environmental conservation, and social well-being. It is important for employment, income generation, plant pollination, ecological awareness, medication, and nutrition. The objective of this review is to explore the improvement of honey production, navigating the causes that reduce honey production as well as techniques to optimize honey production, opportunities, and future prospects in Africa. The improvement of honey production in Africa faces various economic, social, and environmental limits that reduce its production. The causes of low honey production include traditional beekeeping system, inadequate management, technical gaps, and environmental factors as well as lack of technological knowledge, inadequate training, and market constraints, which collectively impede the producers’ ability to improve their honey production. Techniques to improve honey production include improving the beekeeping management system, enhancing forage resources, post-harvest, and value addition, and capacity building and extension services. Improved honey production opportunities include the expansion of beekeeping as an agribusiness, the availability of rich floral diversity to high-quality honey, the adoption of modern beekeeping technologies, resilience to climate change with pollination services, access to both local and export markets, and the incorporation of digital and mobile innovations in beekeeping practices. By strengthening honey production through investment in modern beekeeping practices, enhancing cooperative structures, improving market access, and supporting policy frameworks, stakeholders possess the capacity to collectively transform the honey sector into a sustainable and resilient industry.
Social network analysis is increasingly and fruitfully applied to study the collective structure and function of animal societies across space and time. Honey bees (Apis mellifera L.) are a particularly tractable model system that is rich in social relationships and dynamics. Despite the rich body of literature describing the social life of the honey bee, including the famous waggle dance by which foragers recruit nestmates to profitable resources, relatively little is known about the networks that arise from waggle dance communication. Here we conducted a field experiment with fully-marked experimental colonies (N = 2 colonies, 3,000 bees each) to characterize the honey bee waggle dance recruitment network structure and function. Particularly, we studied network density, burstiness in waggle dance bouts, and the effect of individuality in waggle dance communication behavior on network structure. We simulated a maximally-efficient honey bee recruitment network using a deterministic susceptible-infected model. Then we used this simulated network as an upper bound for network density to calculate the proportion of successful recruitment events in observed networks compared to the simulated maximal network. Next, we characterized the burstiness, or temporal distribution, of waggle dance bouts. Finally, we tested whether inter-bee differences, or individuality, in waggle dance communication affected the recruitment network structure. We found that (1) real recruitment networks are sparse, with each individual recruiting up to 3.5% as many nestmates as predicted by the simulated maximal network; (2) individual bees danced steadily, not in bursts, and (3) that individuality in waggle dance calibrations was positively associated with successful recruitment and thus the propagation of the recruitment network (p = 0.008). Our results offer the first empirical and biologically-informed descriptive statistics for honey bee waggle dance networks and may be informative in the parameterization of bio-inspired computing models.
Climate change is one of the main drivers of biological reorganization, population decline of pollinators, and disruption of species interactions. These impacts represent a major threat to crop pollination and human food security. Here, we tested the hypothesis that the spatial mismatches between Neotropical food plant species and their bee pollinators are exacerbated under scenarios of projected climate change. To investigate this hypothesis we performed species distribution modeling to simulate the effects of climate change on suitable habitats for the occurrence of both native food plants and their main pollinators. We selected three economically important food plants native to Brazil bearing a self-incompatible reproductive system that is strictly dependent on pollinators: (1) Bertholletia excelsa, (2) Eugenia uniflora, and (3) Passiflora edulis; and we selected the main effective bee pollinators of each plant species: (1) Apis mellifera (i.e., pollinator of E. uniflora), (2) Eulaema mocsaryi (i.e., pollinator of B. excelsa), and (3) Xylocopa frontalis (i.e., pollinator of P. edulis). We documented that climate change will likely distinctly affect areas of suitable habitats for food plants and their main bee pollinators across Brazil, in which all species will likely experience contractions in their ecological niches. In addition, we also documented that suitable habitats were reduced for the co-occurrence of all food plants and their pollinators. Specifically, 51.5% for P. edulis and X. frontalis, 76% for B. excelsa and E. mocsaryi, and 54% for E. uniflora and A. mellifera. Therefore, these findings underscore that plausible climate change scenarios can act as a potential driver of spatial mismatches between food plants and their main pollinators, disrupting the pollination of these food plants. Our results show that plant and pollinator species respond negatively to the impacts of climate change under all scenarios, which can result in alarming projections for strictly bee-pollinated self-incompatible plant species. This study reaffirms that bees are sensitive to climate change, highlighting the negative impact even for the exotic European honeybee, Apis mellifera. Finally, climate change could impact crop pollination, with detrimental implications for food production and food security.
Of the about 1850 species of Hymenoptera for which chromosome counts are known, only just over 200 of these are bees (Apoidea). Haploid numbers (n) range from 3-28, which probably does represent the true range of chromosome numbers in this superfamily. The modal number is 17, with another peak at n=9, representing a clade of meliponid bees which has been well studied. Although much is known about the chromosomes of bees there is still much to learn about overall trends in haploid number and chromosome organization. We are still lacking this information for many important families of bees. The only andrenid bee karyotyped, Andrena togashii has the low n of 3, so we certainly need to know which other species in this family have low chromosome numbers to see if this is an exception and to further test the Minimum Interaction Theory (MIT) of Imai and colleagues which predicts the evolutionary increase in chromosome number. In general, an overall increase from low numbers (n=3-8) to the higher numbers found in the Apidae, Colletidae, Halictidae, and Megachilidae (modal numbers 17, 16, 16, 16, respectively) does appear to be followed. However, within groups this is not always the case; the Meliponid clade with n=9 being an example. The potential adaptive value of chromosome number per se is of great interest. I propose a hypothesis to account for the high (n=25) chromosome number found in the social parasitic bumble bee subgenus Psithyrus. More sophisticated techniques beyond chromosome counting and karyotyping using C-banding, will yield much more detailed information about chromosomal rearrangements as shown by the work on the neotropical meliponid bees by the Brazilian cytogeneticists, and when these are applied to other taxa of bees will undoubtedly reveal features of great interest. Genomic approaches are starting to identify chromosomal rearrangements such as inversions and this holds much potential to explore their adaptive significance.
IntroductionIn Australia, as well as many other regions of the world, European honey bees Apis mellifera are an introduced species and may harm native bee fauna by competing with them for food resources. Field studies have revealed negative associations between honey bee and native bee abundance, but whether this translates to fitness costs for native bees is unclear.MethodsUsing drilled wooden-block trap nests, we evaluated whether honey bee abundance is associated with fitness parameters (number of nests, provisioned cells per nest, offspring number, mortality rate, sex ratio, and body size) of cavity-nesting native bees over 2 years. We also conducted palynological analyses to measure pollen resource overlap and evaluate whether this impacts native bee fitness.Results and discussionGreater honey bee abundance was associated with a male-biased sex ratio in the native bee progeny across years and an increased mortality rate of native bee progeny in the first year. Most non-significant associations were also in the directions predicted from honey bees adversely impacting native bee fitness. In the first year, greater pollen morphospecies overlap was associated with fewer provisioned cells. In conclusion, we demonstrated that honey bees have the potential to have harmful consequences for native bee fitness.
IntroductionBumblebees are essential pollinators in temperate regions of the northern hemisphere. Niche overlap and competition with honeybees may impose significant stress on bumblebees by reducing nutrient acquisition and increasing the risk of pathogen and parasite spillover from honeybees. One of these parasites is the bumblebee wax moth (Aphomia sociella), whose larvae can be found in bumblebee and wasp nests, as well as weakened commercial honeybee hives (hereafter called apiaries).MethodsUsing Bombus terrestris colonies as experimental models, we expected that young queen and worker bumblebee immunity (measured by encapsulation response) would become weaker under both competitive (i.e., proximity to apiaries) and parasite (A. sociella infestation) pressure and, specifically, that the immunity of bumblebees in closest proximity to apiaries would be weakest in nests infested by A. sociella.Results and discussionWe observed increased infestation, lower reproductive output, and weaker encapsulation response in bumblebee colonies that were near apiaries. Our data provide insights on the ecology of A. sociella infestations where honeybees and bumblebees coexist. Our observations of reduced immune response in bumblebees inhabiting colonies nearer to apiaries are of critical importance, as this reduction in immune response could facilitate additional infestations of other parasites and pathogens within bumblebee colonies.
Pests and pathogens are a primary threat to honey bee (Apis mellifera) colonies worldwide. Selective breeding for honey bees resistant to these stressors represents a promising approach for mitigating their impacts on honey bee health. UBeeO is a novel hygiene-eliciting selection tool that has been used to identify honey bee colonies that are resistant to the parasitic mite Varroa destructor, and that are more likely to survive winter without beekeeper intervention. Here, we used three separate case studies to evaluate the effectiveness of the UBeeO assay in identifying colonies resist to disease. In three distinct geographic regions, we measured UBeeO scores along with the prevalence and load of key fungal and viral honey bee pathogens. We show that UBeeO can be used to identify colonies resistant to several other diseases, including the two fungal pathogens chalkbrood (Ascosphaera apis) and Vairimorpha spp. (previously Nosema), and multiple viruses, all critically important to honey bee health and survival. Furthermore, we identify potential UBeeO resistance thresholds for each pathogen, demonstrating an inverse relationship between pathogen virulence and the minimum UBeeO score associated with resistance to that pathogen. These findings suggest that UBeeO-guided selection strategies have the potential to significantly improve honey bee breeding programs by facilitating identification of resilient and pathogen-resistant colonies. The broad geographic range of our study sites underscores the robustness and applicability of UBeeO across varying environmental contexts. Since honey bees provide essential pollination services in both natural and agricultural ecosystems, this work has major implications for environmental health, crop productivity, and food security on a global scale.
IntroductionIn beekeeping, queen cell size is a critical factor influencing the growth and development of queen bees. It was hypothesized that larger queen cells would produce queens with greater weight, enhanced resilience to heat stress, and higher expression of heat shock proteins (HSP90 and HSC70), leading to improved survival under environmental stress.Materials and methodsThis study, conducted in Shiraz Province, Iran, in 2023, aimed to test this hypothesis. A total of 270 queens were divided into three groups based on queen cell size: large (10–9.5 mm), medium (9–8.5 mm), and small (7.5–7 mm). The queens were reared using three different methods: 1) simultaneous starter_finisher colonies, 2) separate starter_finisher colonies, and 3) rearing in the presence of the queen. Since there were three different cell types, this resulted in a total of 90 cells for each rearing method. Each group of 90 cells consisted of three subsets of 30 cells: large, small, and medium. From 270 cells, 176 survived and 94 queens died.Results and discussionWe conducted a stepwise procedure using a logistic model, and the results indicated that the model, which included cell type, rearing method, and birth weight, showed the best predictive performance. This was evidenced by the lowest Akaike information criterion value. Then, from rearing method 2, we placed 12 queens of each cell type in two groups of six each subjected to two different stress levels: a low temperature of 4°C and a high temperature above 40°C. A total of 36 frozen queen samples with six replicates for each treatment combination were used for molecular testing. Gene expression analysis was conducted using real-time PCR to evaluate HSP90 and HSC70 gene expression. Results showed that queens produced in larger cells had significantly higher weight, enhanced resilience to heat stress, and higher gene expression of HSP90. These queens demonstrated superior survival rates under high-temperature conditions compared to queens from smaller cells.ConclusionsThe findings support the hypothesis that optimizing queen cell size can enhance queen performance and colony resilience. Our results suggest that larger cells promote improved development, heat stress resilience, and higher survival rates, ultimately improving colony health and productivity.
Declining social insects such as bumble bees are particularly vulnerable to loss of genetic diversity. Population delimitation is a precondition for measuring genetic diversity but usually requires extensive genetic data and comprehensive knowledge about gene flow barriers. As a first step towards a delimitation strategy that does not rely on genetic data, we compiled existing knowledge about Bombus population structures and (potential) gene flow barriers. We reviewed studies examining genetic structuring in Bombus species and assessed the impact of different ecological and environmental factors on their gene flow. Generally, we found that declining species and clearly isolated populations exhibit genetic structuring for which some underlying factors can be correlated with isolation-by-landscape approaches. For widespread species, isolation-by-environment approaches can help elucidate subtle factors impeding gene flow between populations, even though such species are capable of maintaining gene flow across large stepping stone populations. However, to better inform isolation-by landscape/environment models that could contribute to a landscape-based population delimitation strategy, more research into habitat requirements and dispersal ranges has to be conducted.
Anthropogenic disturbances mainly involve the loss of habitats in tropical regions where there is also significant population growth. These disturbances also have an impact on the plant pollination service, which is struggling to be explored in the Lubumbashi region, where mining interests seem to take priority given the local connotations and the predominance of players within the sector. The present study focuses on an analysis of the pollination service and the interactions maintained between bees and their host plants, in a context of agricultural impetus through the practice of agroforestry, the benefits of which supposedly extend from improved yields to efforts to conserve global biodiversity. Subject to the sampling effort at the limits of the favorable periods, our results indicate a significant biodiversity of bees, unevenly distributed among the families Apidae, Halictidae and Megachilidae. The species Xylocopa albiceps, Nomia speciosana, X. olivaceae and Megachile torrida dominate the abundance ranks, while more restricted than general interactions between pollinators and their host plants are recorded.
