Managed Honey Bee Research Articles

Biodiversity measures of a grassland plant-pollinator community are resilient to the introduction of honey bees (Apis mellifera).

The prairies of Canada support a diversity of insect pollinators that contribute pollination services to flowering crops and wild plants. Habitat loss and use of managed pollinators has increased conservation concerns for wild pollinators, as mounting evidence suggests that honey bees (Apis mellifera) may reduce their diversity and abundance. Plant-pollinator community analyses often omit non-bee pollinators, which can be valuable contributors to pollination services. Here, we experimentally introduced honey bees to examine how their abundance affects the species richness, diversity, abundance, species composition, interaction richness, and interaction diversity of all wild pollinators, and of four higher taxa separately. We identified all insect pollinators and analyzed how honey bee abundance affected the above biodiversity metrics, controlling for flower abundance and flower species richness. Even with high honey bee densities, there was no change to any of these variables, except that beetle species diversity increased. All other taxa had no significant relationship to honey bee abundance. Considering the widespread use of managed honey bees, the effect they have on wild pollinators should be firmly established. Our results suggest that honey bees have little to no short-term impact on the wild pollinator community or its interactions with plants in this native grassland.

Foraging behaviour and pollinator dynamics in lucerne crop of the Bundelkhand region: Implications for crop management in the subtropics

Abstract Pollination stands out as the paramount ecosystem service facilitated by insect pollinators, providing benefits to over three quarters of the world’s major crops. The conservation and effective management of honeybees constitute integral components for ensuring the sustainable productivity of cross-pollinated crops. The present study aimed to document the potential pollinators of lucerne in the Bundelkhand region in India, which is known for its subtropical climatic conditions. Further, the foraging behaviour, including foraging rate and speed, was meticulously documented. A total of 13 insect species from seven families across three insect orders were observed visiting lucerne flowers. Hymenopterans comprised the majority of the floral visitors (73.48%), followed by Lepidoptera (26.51%) during the study period. Among them, Apis dorsata (Hymenoptera: Apidae) emerged as the most predominant floral visitor, exhibiting peak activity at 12:00 h with a density of 7.85 bees/m2/10 min. Surprisingly, among the major floral visitors, A. florea has the highest mean foraging rate (number of flowers visited/minute/forager), i.e., 11.56, 11.59 and 10.79 bees/flowers/minute during the initial flowering stage, peak flowering stage and late flowering stage, respectively. However, the foraging speed (time spent by the forager on each flower) was longest in A. dorsata, i.e., 5.05, 3.78 and 5.41 s/flower during initial, peak and late flowering stages, respectively. The findings emphasize the importance of enhancing honeybee activity to boost lucerne seed yield. Further, the outcomes of the study can be leveraged to optimize honeybee colony management, scheduling field operations such as pesticide application and weeding during periods of minimal honeybee activity.

Pollen trapping as Honeybees pollination management and identification of dominant pollinators of Guizotia abyssinica (L.f).

Pollination is one of the most fascinating aspects of insect-plant interactions. Pollen is the male reproductive element of flowering plants, gathered by foraging Honeybees from the male parts of flowering plants called the anther. Guizotia abyssinica (L.f) is an important oilseed crop cultivated in Ethiopia and India, which belongs to the family Asteraceae. Although self-incompatibility is found in Guizotia abyssinica, a higher seed set is experienced in places with an active Honeybees population. Agricultural practices usually focus on inputs such as fertilizer application to improve seed yield of Guizotia abyssinica. However, these practices have little effect on yield if the availability of insect pollination is too low. To fill this gap, an experiment was carried out at Dandi district, West Shao zone, Oromia, Ethiopia to see the effect of Honeybees pollination management as an agronomic input. Pollination management of Honeybees was tested under feeding and non-feeding of colonies management. Pollen was trapped with and without sugar syrup feeding. The results discovered that Honeybees fed sugar syrup collected much more pollen than colonies not fed sugar syrup. The proportion of Guizotia abyssinica pollen collected through sugar syrup feeding of the colony was greater (62.2%), compared to the proportion of Guizotia abyssinica pollen trapped without sugar syrup feeding (37.8%). This indicates that sugar syrup feeding enhances the collection of pollen and probably enhances the pollination efficiency of Honeybees since they visit frequently to fulfill their daily protein requirement of pollen. Therefore, Honeybees pollination services should be included as one of the agronomic inputs with sugar syrup feeding as pollination management that might increase the yield of Guizotia abyssinica since it increases visiting frequency.

Discrete Time Series Forecasting of Hive Weight, In-Hive Temperature, and Hive Entrance Traffic in Non-Invasive Monitoring of Managed Honey Bee Colonies: Part I.

From June to October, 2022, we recorded the weight, the internal temperature, and the hive entrance video traffic of ten managed honey bee (Apis mellifera) colonies at a research apiary of the Carl Hayden Bee Research Center in Tucson, AZ, USA. The weight and temperature were recorded every five minutes around the clock. The 30 s videos were recorded every five minutes daily from 7:00 to 20:55. We curated the collected data into a dataset of 758,703 records (280,760-weight; 322,570-temperature; 155,373-video). A principal objective of Part I of our investigation was to use the curated dataset to investigate the discrete univariate time series forecasting of hive weight, in-hive temperature, and hive entrance traffic with shallow artificial, convolutional, and long short-term memory networks and to compare their predictive performance with traditional autoregressive integrated moving average models. We trained and tested all models with a 70/30 train/test split. We varied the intake and the predicted horizon of each model from 6 to 24 hourly means. Each artificial, convolutional, and long short-term memory network was trained for 500 epochs. We evaluated 24,840 trained models on the test data with the mean squared error. The autoregressive integrated moving average models performed on par with their machine learning counterparts, and all model types were able to predict falling, rising, and unchanging trends over all predicted horizons. We made the curated dataset public for replication.

The IMPACT OF HONEYBEE GUT BACTERIA ON THE SURVIVAL OF HONEYBEES EXPOSED TO INSECTICIDES

The widespread use of insecticides poses a significant threat to the health and sustainability of honeybees (Apis mellifera). This study aimed to isolate, identify, and investigate the potential of honeybee gut bacterial strains in mitigating the detrimental effects of insecticides on honeybees and extending their lifespan. The efficacy of seven honeybee gut bacterial strains in reducing insecticide toxicity was evaluated. Through the identification of honeybee gut bacterial isolates using 16s rRNA, seven strains were identified, namely Priestia endophytica, Bacillus subtilis, Bacillus pumilus, Peribacillus frigoritolerans, B. subtilis, Bacillus pumilus, and Bacillus tequilensis. The experimental results revealed that bees treated with these gut bacteria significantly reduced oxidative stress markers and detoxification enzyme levels compared to untreated bees. Moreover, the treated bees demonstrated enhanced immune responses. The bees treated with deltamethrin + intestinal bacteria showed an increase in bees' lifespan to 6.33 days compared to a lifespan of 4 days with deltamethrin only. Similarly, bees treated with acetamiprid intestinal bacteria had further extended to 10.33 days compared to a lifespan of 7.67 days with acetamiprid. These findings suggest that using honeybee gut bacterial strains may serve as a sustainable strategy to mitigate the harmful impacts of insecticides on honeybees, thereby promoting their overall health and contributing to the preservation of pollination services and apiculture. Further research is warranted to elucidate the underlying mechanisms and optimize the application of these natural products in honeybee management practices.

Nutritional position of managed honey bees during pollination of native plants by the melissopalynology method

Pollination services are crucial for maintaining ecological stability and ensuring food security for humans. Managed honey bees, which are economically valuable and are experiencing population growth due to the increasing demand for their products, play a significant role in pollination. To produce high-quality honey, beekeepers often choose natural high meadows, characterized by high plant species richness, for their apiaries. This practice, in turn, may contribute to the pollination of native plants, as managed honey bees are likely to forage on diverse floral resources within these meadows In this study, we investigated the nutritional position of managed bees in the pollination of native plants in Iran using the melissopalynology method to determine the extent of their contribution to the pollination of native plants. Ninety-four honey samples were collected from beekeepers located in the natural pastures of two biodiversity hotspots in Iran (Zagros and Alborz). Then, plant pollens were extracted from the honey and photographed by scanning electron microscopy. In the next step, plant species were identified, and their abundance was calculated. The results showed that managed bees visited 54 plant genera, seven of which were non-native plants. Additionally, more plant species and the highest abundance of pollen were observed at altitudes ranging from 1000 to 3000 m. Therefore, beekeepers set up their hives in this altitude range to obtain high-quality honey. In general, in this study, the results of melissopalynological analysis, involving the identification of plant genera and pollen counts, revealed that managed honey bees likely contributed less than 3% to the pollination of native plant species in Iran.

Introgressive hybridisation puts the distinctive population of Apis mellifera mellifera in Ireland at risk: evidence from a multidisciplinary approach

Apis mellifera mellifera a honey bee subspecies at risk of extinction across much of its range has a stronghold in Ireland where it is the native honey bee subspecies and is referred to as the black bee. However, an increase in imports of other subspecies and commercial strains is now a major threat to its genetic integrity. Furthermore, despite assertions by Irelands’ beekeepers that the black bee is a distinct ecotype, little taxonomic work has focused on this population. Here we liaise with beekeepers and assess the managed honey bee cohort for signs of increased introgression. We also investigate morphological variation in A. m. mellifera colonies to establish for the first time a description of this subspecies in Ireland. SNPs and mitochondrial data indicate a further increase in introgression in the population even though much of the population remains A. m. mellifera. The morphology of Irish A. m. mellifera has deviated significantly from European populations and can be characterised as being smaller and hairier, with a broad abdomen, shorter legs and a shorter proboscis. Their fore wings are longer but with a smaller cubital index. These attributes may have evolved as adaptations to the unique environmental and climatic conditions found in Ireland but may also have been influenced by artificial selection and/or genetic drift.

Genomic diversity and population structure of Carniolan honey bee in its native habitat

BackgroundResearch into the genetic diversity of honey bee (Apis melliferaL.) populations has become increasingly significant in recent decades, primarily due to population declines attributed to human activities and climate change. As a species of great importance, breeding programs that leverage understanding of genomic diversity could offer solutions to mitigate these challenges. The objective of this study was to examine the genomic diversity and population structure of Carniolan honey bees (Apis mellifera carnica) using the Illumina SNP chip on a large honey bee sample collected from Central and South-Eastern European countries. The study also aims to offer recommendations for future breeding programs.ResultsOur analysis involved Discriminant Analysis of Principal Components (DAPC), heterozygosity, admixture analysis, fixation indices (FST), Neighbour-Joining tree, gene flow and Isolation-by-distance analysis. DAPC indicated distinct separation between the Carniolan and Italian honey bee (Apis mellifera ligustica) populations, whereas the admixture analysis revealed varying levels of gene flow and genetic admixture within the Carniolan honey bee populations, demonstrating closer relationships between specific geographic regions (confirmed by Isolation-by-distance analysis). Furthermore, the research of heterozygosity, genomic inbreeding, pairwise FST values, and Neighbour-Joining tree provided insights into the patterns of genetic differentiation and similarity among the populations of Carniolan honey bee within its natural habitat. We have observed genetic homogeneity of the Carniolan honey bee population when considered in a broader genetic/geographical context. However, the Carniolan honey bee has sufficient genetic diversity in its geographical home range that needs to be carefully monitored and maintained.ConclusionsThis study provides important insights into the genetic composition, differentiation, and relationships among Carniolan honey bee populations in Central and South-Eastern European countries. The findings are crucial for conservation efforts, breeding programs, and sustainable beekeeping practices. They emphasise the importance of considering genetic factors and population structure in the breeding and management of honey bees. By understanding these genetic relationships, we can develop strategies to preserve genetic diversity, improve breeding outcomes, and ensure the resilience of honey bee populations in the face of environmental changes and challenges. This knowledge can also inform policy makers and stakeholders on best practices to maintain healthy bee populations, which are vital for ecosystem services and agricultural productivity.

Estimating genus-specific effects of non-native honey bees and urbanization on wild bee communities: A case study in Maryland, United States

Non-native species have the potential to detrimentally affect native species through resource competition, disease transmission, and other forms of antagonism. The western honey bee (Apis mellifera) is one such species that has been widely introduced beyond its native range for hundreds of years. There are strong concerns in the United States, and other countries, about the strain that high-density, managed honey bee populations could pose to already imperiled wild bee communities. While there is some experimental evidence of honey bees competing with wild bees for resources, few studies have connected landscape-scale honey bee apiary density with down-stream consequences for wild bee communities. Here, using a dataset from Maryland, US and joint species distribution models, we provide the largest scale, most phylogenetically resolved assessment of non-native honey bee density effects on wild bee abundance to date. As beekeeping in Maryland primarily consists of urban beekeeping, we also assessed the relative impact of developed land on wild bee communities. Six of the 33 wild bee genera we assessed showed a high probability (> 90 %) of a negative association with apiary density and/or developed land. These bees were primarily late-season, specialist genera (several long-horned genera represented) or small, ground nesting, season-long foragers (including several sweat bee genera). Conversely, developed land was associated with an increase in relative abundance for some genera including invasive Anthidium and other urban garden-associated genera. We discuss several avenues to ameliorate potentially detrimental effects of beekeeping and urbanization on the most imperiled wild bee groups. We additionally offer methodological insights based on sampling efficiency of different methods (hand netting, pan trapping, vane trapping), highlighting large variation in effect sizes across genera. The magnitude of sampling effect was very high, relative to the observed ecological effects, demonstrating the importance of integrated sampling, particularly for multi-species or community level assessments.

Comparative prevalence of Nosema ceranae infection between wild and managed honey bee(Apis mellifera) colonies in South Texas

Comparative prevalence of Nosema ceranae infection between wild and managed honey bee(Apis mellifera) colonies in South Texas

The health of managed and wild-living Western honey bee colonies, Apis mellifera, on Guam

A survey conducted as part of the National Honey Bee Survey from 2013 to 2020 quantified the managed honey bee hives on Guam, sampled accessible wild-living colonies, and described associated diseases and pests. During this period the number of managed bee colonies increased from 20 to 121 which was associated with the formation of the Guam Beekeepers Association. Managed Apis mellifera colonies on Guam had significantly fewer parasites and diseases than reported in the USA. The Varroa mite, Varroa destructor, was detected in 2014 in a wild-living colony in southern Guam. The greater banded hornet, Vespa tropica, was first observed on Guam in 2016, with honey bee depredations observed in 2017. Nosema ceranae was initially detected in wild-living and managed colonies in 2013 and has been consistently observed since that time with little apparent effect on colony health as there have been no recorded colony losses in apiaries. No small hive beetle, Aethina tumida, Tropilaelaps mite, Tropilaelaps spp, American foulbrood, Paenibacillus larvae, European foulbrood, Melissococcus plutonius, chalkbrood, Ascosphaera sp. and 11 additional viral diseases of the 22 known to infest honey bees, including deformed wing virus, were observed.

Landscape structure affects temporal dynamics in the bumble bee virome: Landscape heterogeneity supports colony resilience

Virus spillovers from managed honey bees, Apis mellifera, are thought to contribute to the decline of wild pollinators, including bumble bees. However, data on the impact of such viruses on wild pollinators remain scarce, and the influence of landscape structure on virus dynamics is poorly understood. In this study, we deployed bumble bee colonies in an agricultural landscape and studied changes in the bumble bee virome during field placement under varying habitat composition and configuration using a multiscale analytical framework. We estimated prevalence of viruses and viral loads (i.e. number of viral genomic equivalent copies) in bumble bees before and after placing them in the field using next generation sequencing and quantitative PCR. The results show that viral loads and number of different viruses present increased during placement in the field and that the virus composition of the colonies shifted from an initial dominance of honey bee associated viruses to a higher number (in both viral loads and number of viruses present) of bumble bee associated viruses. Especially DWV-B, typical for honey bees, drastically decreased after the time in the field. Viral loads prior to placing colonies in the field showed no effect on colony development, suggesting low impacts of these viruses in field settings. Notably, we further demonstrate that increased habitat diversity results in a lower number of different viruses present in Bombus colonies, while colonies in areas with well-connected farmland patches decreased in their total viral load after field placement. Our results emphasize the importance of landscape heterogeneity and connectivity for wild pollinator health and that these influences predominate at fine spatial scales.

Higher prevalence of sacbrood virus in Apis mellifera (Hymenoptera: Apidae) colonies after pollinating highbush blueberries.

Highbush blueberry pollination depends on managed honey bees (Apis mellifera) L. for adequate fruit sets; however, beekeepers have raised concerns about the poor health of colonies after pollinating this crop. Postulated causes include agrochemical exposure, nutritional deficits, and interactions with parasites and pathogens, particularly Melisococcus plutonius [(ex. White) Bailey and Collins, Lactobacillales: Enterococcaceae], the causal agent of European foulbrood disease, but other pathogens could be involved. To broadly investigate common honey bee pathogens in relation to blueberry pollination, we sampled adult honey bees from colonies at time points corresponding to before (t1), during (t2), at the end (t3), and after (t4) highbush blueberry pollination in British Columbia, Canada, across 2 years (2020 and 2021). Nine viruses, as well as M. plutonius, Vairimorpha ceranae, and V. apis [Tokarev et al., Microsporidia: Nosematidae; formerly Nosema ceranae (Fries et al.) and N. apis (Zander)], were detected by PCR and compared among colonies located near and far from blueberry fields. We found a significant interactive effect of time and blueberry proximity on the multivariate pathogen community, mainly due to differences at t4 (corresponding to ~6 wk after the beginning of the pollination period). Post hoc comparisons of pathogens in near and far groups at t4 showed that detections of sacbrood virus (SBV), which was significantly higher in the near group, not M. plutonius, was the primary driver. Further research is needed to determine if the association of SBV with highbush blueberry pollination is contributing to the health decline that beekeepers observe after pollinating this crop.

Known and novel viruses in Belgian honey bees: yearly differences, spatial clustering, and associations with overwintering loss.

The western honey bee (Apis mellifera) is a highly effective pollinator of flowering plants, including many crops, which gives honey bees an outstanding importance both ecologically and economically. Alarmingly high annual loss rates of managed honey bee colonies are a growing concern for beekeepers and scientists and have prompted a significant research effort toward bee health. Several detrimental factors have been identified, such as varroa mite infestation and disease from various bacterial and viral agents, but annual differences are often not elucidated. In this study, we utilize the viral metagenomic survey of the EPILOBEE project, a European research program for bee health, to elaborate on the most abundant bee viruses of Flanders. We complement the existing metagenomic data with absolute viral loads and their spatial and temporal distributions. Furthermore, we identify Apis orthomyxovirus 1 as a potentially emerging pathogen, as we find evidence for its active replication honey bees.

Dominance of African racial ancestry in honey bee colonies of Mexico 30 years after the migration of hybrids from SouthAmerica.

The Africanized honey bee, a hybrid of Apis mellifera scutellata from Africa with European subspecies, has been considered an invasive species and a problem for beekeeping. Africanized bees arrived in Mexico in 1986, 30 years after their accidental release in Brazil. Although government programs were implemented for its eradication, Africanized populations persist in Mexico, but precise information on the patterns of genetic introgression and racial ancestry is scarce. We determined maternal and parental racial ancestry of managed and feral honey bees across the five beekeeping regions of Mexico, using mitochondrial (mtDNA, COI-COII intergenic region) and nuclear markers (94 ancestrally informative SNPs), to assess the relationship between beekeeping management, beekeeping region, altitude, and latitude with the distribution of maternal and parental racial ancestry. Results revealed a predominantly African ancestry in the Mexican honey bees, but the proportion varied according to management, beekeeping regions, and latitude. The Mexican honey bees showed 31 haplotypes of four evolutionary lineages (A, M, C, and O). Managed honey bees had mitochondrial and nuclear higher proportions of European ancestry than feral honey bees, which had a higher proportion of African ancestry. Beekeeping regions of lower latitudes had higher proportions of African nuclear ancestry. Managed and feral honey bees showed differences in the proportion of maternal and nuclear racial ancestry. Managed honey bees from the Yucatan Peninsula and feral honey bees had a higher mtDNA than nuclear proportions of African ancestry. Managed honey bees, except those on the Yucatan Peninsula, had a higher nuclear than mtDNA proportion of African ancestry. Our study demonstrates that Africanized honey bee populations are genetically diverse and well established in Mexico, which highlights the limitations of management and government programs to contain the Africanization process and demands the incorporation of this lineage in any breeding program for sustainable beekeeping.

Occurrence of Lotmaria Passim in Africanized and European Honey Bee, Apis Mellifera, Lineages from the United States

Abstract Honey bee populations in the United States have been under stress for the past several decades. Several internal parasites may contribute to this, including the trypanosome Lotmaria passim. It is unknown how widespread the honey bee parasite, L. passim, is in Africanized honey bee (AHB) populations in the United States. A total of 321 feral honey bee colony samples which had been previously recorded to be of Africanized origin using molecular diagnostics from California (n=3), New Mexico (n=46), Oklahoma (n=57), Texas (n=106), and Utah (n=109) were used in this study. Of these samples, a total of 15 (4.7%) from three States were positive for L. passim. Utah AHB samples had the highest infection rate (11.0%), followed by Texas (1.9%) and Oklahoma (1.8%). Compared with previous studies on the occurrence of L. passim from European honey bees from the same sampled States, infection rates of Africanized honey bees for L. passim were significantly higher in the State of Utah, but not for the other sampled States. This study provides evidence that feral honey bee populations do not necessarily have lower levels of honey bee parasites than managed honey bee colonies.

First large-scale study reveals important losses of managed honey bee and stingless bee colonies in Latin America

Over the last quarter century, increasing honey bee colony losses motivated standardized large-scale surveys of managed honey bees (Apis mellifera), particularly in Europe and the United States. Here we present the first large-scale standardized survey of colony losses of managed honey bees and stingless bees across Latin America. Overall, 1736 beekeepers and 165 meliponiculturists participated in the 2-year survey (2016–2017 and 2017–2018). On average, 30.4% of honey bee colonies and 39.6% of stingless bee colonies were lost per year across the region. Summer losses were higher than winter losses in stingless bees (30.9% and 22.2%, respectively) but not in honey bees (18.8% and 20.6%, respectively). Colony loss increased with operation size during the summer in both honey bees and stingless bees and decreased with operation size during the winter in stingless bees. Furthermore, losses differed significantly between countries and across years for both beekeepers and meliponiculturists. Overall, winter losses of honey bee colonies in Latin America (20.6%) position this region between Europe (12.5%) and the United States (40.4%). These results highlight the magnitude of bee colony losses occurring in the region and suggest difficulties in maintaining overall colony health and economic survival for beekeepers and meliponiculturists.

Faster-growing parasites threaten host populations via patch-level population dynamics and higher virulence; a case study in Varroa mites (Mesostigmata: Varroidae) and honey bees (Hymenoptera: Apidae).

Honey bee parasites remain a critical challenge to management and conservation. Because managed honey bees are maintained in colonies kept in apiaries across landscapes, the study of honey bee parasites allows the investigation of spatial principles in parasite ecology and evolution. We used a controlled field experiment to study the relationship between population growth rate and virulence (colony survival) of the parasite Varroa destructor (Anderson and Trueman). We used a nested design of 10 patches (apiaries) of 14 colonies to examine the spatial scale at which Varroa population growth matters for colony survival. We tracked Varroa population size and colony survival across a full year and found that Varroa populations that grow faster in their host colonies during the spring and summer led to larger Varroa populations across the whole apiary (patch) and higher rates of neighboring colony loss. Crucially, this increased colony loss risk manifested at the patch scale, with mortality risk being related to spatial adjacency to colonies with fast-growing Varroa strains rather than with Varroa growth rate in the colony itself. Thus, within-colony population growth predicts whole-apiary virulence, demonstrating the need to consider multiple scales when investigating parasite growth-virulence relationships.

Evaluating the seasonal efficacy of commonly used chemical treatments on Varroa destructor (Mesostigmata: Varroidae)populationresurgence in honey bee colonies.

The purpose of this research was to determine how common chemical treatments influence Varroa destructor (Anderson and Trueman) populationresurgence rates (defined as time posttreatment for mite populations to reach 3 mites/100 adult bees) in managed honey bee (Apis mellifera L.) colonies seasonally. We conducted 2 experiments that followed the same basic protocol to address this purpose. We established 6 treatment groups in Experiment 1 in the fall of 2014: untreated control, Apivar, Apistan, CheckMite+, ApiLifeVar, and Mite Away II applied to 10 colonies per treatment. In Experiment 2, we applied 8 chemical treatments to each of 4 seasonal (spring, summer, fall, and winter) cohorts of honey bee colonies to determine how mite populations are influenced by the treatments. The treatments/formulations tested were Apivar, Apistan, Apiguard, MAQS, CheckMite+, oxalic acid (dribble), oxalic acid (shop towels), and amitraz (shop towels soaked in Bovitraz). In Experiment 1, Apivar and Mite Away II were able to delay V. destructor resurgence for 2 and 6 months, respectively. In Experiment 2, Apiguard, MAQS, oxalic acid (dribble), and Bovitraz treatments were effective at delaying V. destructor resurgence for at least 2 months during winter and spring. Only the Bovitraz and MAQS treatments were effective at controlling V. destructor in the summer and fall. Of the 2 amitraz-based treatments, the off-label Bovitraz treatment was the only treatment to reduce V. destructor populations in every season. The data gathered through this study allow for the refinement of treatment recommendations for V. destructor, especially regarding the seasonal efficacy of each miticide and the temporal efficacy posttreatment.

Effective pest management approaches can mitigate honey bee (Apis mellifera)colony winter loss across a range of weather conditions in small-scale, stationary apiaries.

Managed honey bee (Apis mellifera L.) colonies in North America and Europe have experienced high losses in recent years, which have been linked to weather conditions, lack of quality forage, and high parasite loads, particularly the obligate brood parasite, Varroa destructor. These factors may interact at various scales to have compounding effects on honey bee health, but few studies have been able to simultaneously investigate the effects of weather conditions, landscape factors, and management of parasites. We analyzed a dataset of 3,210 survey responses from beekeepers in Pennsylvania from 2017 to 2022 and combined these with remotely sensed weather variables and novel datasets about seasonal forage availability into a Random Forest model to investigate drivers of winter loss. We found that beekeepers who used treatment against Varroa had higher colony survival than those who did not treat. Moreover, beekeepers who used multiple types of Varroa treatment had higher colony survival rates than those who used 1 type of treatment. Our models found weather conditions are strongly associated with survival, but multiple-treatment type colonies had higher survival across a broader range of climate conditions. These findings suggest that the integrated pest management approach of combining treatment types can potentially buffer managed honey bee colonies from adverse weather conditions.