Feral Honey Bee Colonies Research Articles

The Varroa paradox: infestation levels and hygienic behavior in feral scutellata-hybrid and managed Apis mellifera ligustica honey bees

The Varroa destructor mite is a parasitic threat to managed and feral honey bee colonies around the world. Beekeepers use miticides to eliminate Varroa in commercial hives, but these chemicals can diminish bee health and increase miticide resistance. In contrast, feral honey bees have developed multiple ways to counteract mites without chemical treatment. We compared mite levels, grooming habits, and mite-biting behavior between feral Africanized honey bees (genomically verified Apis mellifera scutellata hybrids) and managed Italian honey bees (A. mellifera ligustica). Surprisingly, there was no difference in mite infestation levels between scutellata-hybrids and managed bees over one year despite the regular use of miticides in managed colonies. We also found no differences in the social immunity responses of the two groups, as measured by their hygienic habits (through worker brood pin-kill assays), self-grooming, and mite-biting behavior. However, we provide the first report that both scutellata-hybrids and managed honey bees bite off mite chemosensory forelegs, which the mites use to locate brood cells for reproduction, to a significantly greater degree than other legs (a twofold greater reduction in foreleg length relative to the most anterior legs). Such biting may impair mite reproduction.

Densities of feral honey bee colonies utilising tree hollows in central Perth, Western Australia

Densities of feral honey bee colonies utilising tree hollows in central Perth, Western Australia

Reduced parasite burden in feral honeybee colonies

Abstract Bee parasites are the main threat to apiculture and since many parasite taxa can spill over from honeybees (Apis mellifera) to other bee species, honeybee disease management is important for pollinator conservation in general. It is unknown whether honeybees that escaped from apiaries (i.e. feral colonies) benefit from natural parasite‐reducing mechanisms like swarming or suffer from high parasite pressure due to the lack of medical treatment. In the latter case, they could function as parasite reservoirs and pose a risk to the health of managed honeybees (spillback) and wild bees (spillover). We compared the occurrence of 18 microparasites among managed (N = 74) and feral (N = 64) honeybee colony samples from four regions in Germany using qPCR. We distinguished five colony types representing differences in colony age and management histories, two variables potentially modulating parasite prevalence. Besides strong regional variation in parasite communities, parasite burden was consistently lower in feral than in managed colonies. The overall number of detected parasite taxa per colony was 15% lower and Trypanosomatidae, chronic bee paralysis virus, and deformed wing viruses A and B were less prevalent and abundant in feral colonies than in managed colonies. Parasite burden was lowest in newly founded feral colonies, intermediate in overwintered feral colonies and managed nucleus colonies, and highest in overwintered managed colonies and hived swarms. Our study confirms the hypothesis that the natural mode of colony reproduction and dispersal by swarming temporally reduces parasite pressure in honeybees. We conclude that feral colonies are unlikely to contribute significantly to the spread of bee diseases. There is no conflict between the conservation of wild‐living honeybees and the management of diseases in apiculture.

Development and assessment of an epidemiologic dashboard for surveillance of Varroa destructor in Ontario apiaries

Varroosis (caused by the Varroa destructor mite) is a key health issue for honey bees in North America. Because these mites can exist in reservoirs of feral honey bee colonies, eradication is impossible, and instead efforts are made to maintain mites below a critical threshold. Monitoring for Varroa mites within a population is key for allocating resources and targeting interventions but surveillance can be difficult and/or expensive. This project aims to reflect on the success of data dashboards developed throughout the 2019-coronavirus pandemic and showcase how these methods can improve surveillance of Varroa mite infestations in Ontario, Canada. Dashboards provide a consistent source of information and epidemiologic metrics through data visualizations, and mobilize data otherwise bound to tables and intermittent reports. In the present work, an interactive dashboard for the surveillance of Varroa mite infestations across the province is proposed. This dashboard was developed using routine ministry inspection data to depict the spatio-temporal distribution of mites across a five-year data collection period. Through interactive figures and plots, able to be disaggregated to a specific region and time frame, this dashboard will allow for members of the beekeeping community to monitor provincial mite levels throughout the season. Seven criteria found to be common across highly actionable COVID-19 dashboards were used in a beta testing stage of development to assess the quality of the dashboard, and critically reflect on its strengths and weaknesses. Furthermore, future directions for surveillance dashboards are explored, including integration with citizen science data collection to develop a comprehensive province-wide surveillance system. The outcome of this project is a functional dashboard proof-of-concept for population-level monitoring of Varroa mites and a model for future tools designed for other species and diseases.

The reliability of honey bee density estimates from trapped drones

Australia has an abundance of feral honey bee colonies. Understanding their densities is important to assess their current economic and ecological impact and the need for mitigation should the mite Varroa destructor become established. Inferring colony density based on the genotypes of honey bee drones (males) caught in a Williams trap has been identified as a promising approach. This method assumes that (a) drones are attracted to the trap from an area bounded by the drone flight range, (b) sufficient colonies present within that radius are represented in a sample and (c) colonies that do not produce drones are small and of little ecological consequence. Here, we investigate whether known feral colonies were represented in drone samples and whether drone contribution per colony correlated with the relative colony size or the distance between the colony and the trap. We found that one-third of known colonies were not represented in the drone sample, and this proportion did not correlate with colony size or distance. For colonies that contributed at least one drone, there was a correlation between the number of drones caught per colony and the distance of the colony from the DCA, and at distances beyond 0.9 km, there was substantial non-detection. Further work is needed to determine an appropriate correction factor that converts the estimated number of colonies represented in a drone sample to colony density.

The Life Span and Levels of Oxidative Stress in Foragers Between Feral and Managed Honey Bee Colonies.

Molecular damage caused by oxidative stress may lead to organismal aging and result in acute mortality to organisms. Thus, oxidative stress resistance and longevity are closely linked. Honey bees (Apis mellifera) are the most important managed pollinator in agriculture, but the long-term survival of honey bees is seriously threatened. Feral honey bee colonies can be used as natural resources to improve honey bee health. One question we ask here is whether feral honey bees are stress resistant or survive longer than managed bee populations. More work is needed to determine the impact of oxidative stress on honey bee health and survival. In this study, we used paired colony designs to compare the life span of worker bees (foragers) between feral and managed colonies and their levels of oxidative stress. Each pair of colonies shared similar foraging resources. The results indicated that foragers in feral colonies had longer survival times and life spans than those in managed colonies. The levels of oxidative stress from lipid damage content in feral colonies were higher than those in managed colonies, indicating that they used a tolerance mechanism rather than a repair mechanism to survive. Our study provides new insights into a colony difference in the physiology and oxidative stress resistance of feral honey bees compared with managed colony stocks.

Co-occurrence of Lotmaria passim and Nosema ceranae in honey bees (Apis mellifera L.) from six states in the United States

Honey bee populations in the United States have been under stress for the past decade. Although no one cause has been able to explain this, recent studies have shown that multiple interactions among microorganisms may be behind honey bee decline. Several internal parasites may contribute to this, including the trypanosome Lotmaria passim and the microsporidian, Nosema ceranae. This study combined novel data with data from several previous molecular diagnostic surveys for L. passim and N. ceranae to determine co-infection rates of these honey bee parasites. A total of 782 honey bee samples from Arkansas, Oklahoma, Texas, Utah, Mississippi, and Hawaii were analyzed for co-occurrence of N. ceranae and L. passim. Of the 782 samples, 37 (4.7%) were co-infected with both N. ceranae and L. passim, while 110 (14.1%) were infected with N. ceranae alone, and 51 (6.5%) with L. passim alone. Co-infections occurred most frequently in honey bees from Hawaii (11.8%), followed by Utah (2.4%) and Arkansas (1.2%), and no co-infections were observed in samples from Mississippi, Oklahoma, or Texas. Statistical analysis revealed that N. ceranae and L. passim co-occur more frequently than expected in samples from Hawaii and Utah. Infection rates for N. ceranae, L. passim, and co-infections were similar between managed (n = 393) and swarms (n = 73) but were both greater than feral (n = 316) honey bee colonies.

Best Management Practices for Live Bee Removals in Florida: A Beekeeper’s Guide


 
 
 
 
 
 
 Feral colonies of honey bees nesting near humans or domestic animals can pose a stinging threat and may be considered a nuisance and possibly a threat to animal or public health, and therefore bees often need to be removed or eradicated when they are found nesting near homes or other property. This 14-page guide written by Mary Bammer, Jamie Ellis, Eric Baxter, Krista Butler, John Coldwell, B. Keith Councell, Kevin Easton, Brendhan Horne, Brandi Stanford, and Amy T. Vu and published by the UF/IFAS Entomology and Nematology Department details best management practices for live bee removals and serves as a reference for beekeepers who choose to perform live bee removal services in Florida.
 
 
 
 
 
 

Molecular survey for the honey bee (Apis mellifera L.) trypanosome parasites Crithidia mellificae and Lotmaria passim

Honey bee populations in the United States have been fluctuating in recent years. Although this has not been attributed to any one cause, recent studies have shown that multiple interactions among mircoorganisms may contribute to their decline. Several honey bee internal parasites have been overlooked as probable causes of decline; these include two different species of trypanosomes Crithidia mellificae and Lotmaria passim. Both parasites have been understudied in honey bee populations and could contribute to population disease dynamics. This study explored a molecular diagnostic survey for C. mellificae and L. passim using multiplex-PCR. Honey bee samples from both feral and managed populations were collected from eight states. This is the first national honey bee trypanosome survey in the United States. A total of 1,360 samples were surveyed during this study in which, 11% were positive for L. passim; while no cases of C. mellificae were detected using multiplex-PCR analysis. Infection rates of states positive for L. passim ranged from 17% (New York) to 0.70% (Utah). Only one state (Mississippi) was not positive for L. passim. The proportion of positive L. passim samples was significantly different between managed and feral honey bee colonies. Results revealed that the honey bee parasitic trypanosome L. passim has a widespread distribution in the United States and should be considered as a potential contributor to honey bee health decline.

The neglected bee trees: European beech forests as a home for feral honey bee colonies.

It is a common belief that feral honey bee colonies (Apis mellifera L.) were eradicated in Europe through the loss of habitats, domestication by man and spread of pathogens and parasites. Interestingly, no scientific data are available, neither about the past nor the present status of naturally nesting honeybee colonies. We expected near-natural beech (Fagus sylvatica L.) forests to provide enough suitable nest sites to be a home for feral honey bee colonies in Europe. Here, we made a first assessment of their occurrence and density in two German woodland areas based on two methods, the tracing of nest sites based on forager flight routes (beelining technique), and the direct inspection of potential cavity trees. Further, we established experimental swarms at forest edges and decoded dances for nest sites performed by scout bees in order to study how far swarms from beekeeper-managed hives would potentially move into a forest. We found that feral honey bee colonies regularly inhabit tree cavities in near-natural beech forests at densities of at least 0.11–0.14 colonies/km2. Colonies were not confined to the forest edges; they were also living deep inside the forests. We estimated a median distance of 2,600 m from the bee trees to the next apiaries, while scout bees in experimental swarms communicated nest sites in close distances (median: 470 m). We extrapolate that there are several thousand feral honey bee colonies in German woodlands. These have to be taken in account when assessing the role of forest areas in providing pollination services to the surrounding land, and their occurrence has implications for the species’ perception among researchers, beekeepers and conservationists. This study provides a starting point for investigating the life-histories and the ecological interactions of honey bees in temperate European forest environments.

The influence of nest site selection on the population dynamics of Africanized honey bees in an urban landscape

AbstractUrban landscapes provide habitat for many species, including domesticated and feral honey bees, Apis mellifera L. (Hymenoptera: Apidae). With recent losses of managed honey bee colonies, there is increasing interest in feral honey bee colonies and their potential contribution to pollination services in agricultural, natural, and urban settings. However, in some regions the feral honey bee population consists primarily of Africanized honey bees. Africanized honey bees (AHB) are hybrids between European honey bees and the African honey bee, Apis mellifera scutellataLepeletier, and have generated economic, ecological, and human health concerns because of their aggressive behavior. In this study, we used two long‐term datasets (7–10 years) detailing the spatial and temporal distribution of AHB colonies in Tucson, AZ, USA, where feral colonies occupy a variety of cavities including water meter boxes. A stage‐structured matrix model was used to elucidate the implications of nest site selection and the effects of colony terminations on the structure and dynamics of the AHB population. Our results suggest that Tucson's AHB population is driven by a relatively small number of ‘source’ colonies that escape termination (ca. 0.165 colonies per km2 or 125 colonies in total), although immigrating swarms and absconding colonies from the surrounding area may have also contributed to the stability of the Tucson AHB population. Furthermore, the structure of the population has likely been impacted by the number and spatial distribution of water meter boxes across the city. The study provides an example of how urban wildlife populations are driven by interactions among landscape structure, human management, and behavioral traits conferred by an invasive genotype.

Higher immunocompetence is associated with higher genetic diversity in feral honey bee colonies (Apis mellifera)

Honey bees are the most important managed pollinators as they provide key ecosystem services for crop production worldwide. Recent losses of honey bee colonies in North America and Europe have demonstrated a need to develop strategies to improve their health and conserve their populations. Previously, we showed that feral honey bees—colonies that live in the wild without human assistance—exhibit higher levels of immunocompetence than managed colonies in North Carolina (USA). In a first attempt to investigate the underlying mechanisms of this difference in immune response, here we characterize the genetic composition of feral and managed honey bees using microsatellite markers. Our results reveal significant but small genetic differentiation between feral and managed honey bee colonies (ϕCT = 0.047, P = 0.03) indicating admixture between these two groups. Higher genetic diversity was correlated with higher immune response in feral (P MANOVA = 0.011) but not managed bees, despite the fact that the latter group showed significantly higher average genetic diversity (P ANCOVA < 0.001). These findings suggest that genetic diversity is positively associated with immunocompetence in feral honey bee colonies, and that the benefits of genetic diversity are obscured in managed bees, perhaps as a result of artificial selection. We hypothesize that high genetic variability provides the raw material upon which natural selection acts and generates adaptive genotypes in unmanaged populations. Feral populations could be useful sources of genetic variation to use in breeding programs that aim to improve honey bee health.

Mating frequencies of honey bee queens (Apis mellifera L.) in a population of feral colonies in the Northeastern United States.

Across their introduced range in North America, populations of feral honey bee (Apis mellifera L.) colonies have supposedly declined in recent decades as a result of exotic parasites, most notably the ectoparasitic mite Varroa destructor. Nonetheless, recent studies have documented several wild populations of colonies that have persisted. The extreme polyandry of honey bee queens—and the increased intracolony genetic diversity it confers—has been attributed, in part, to improved disease resistance and may be a factor in the survival of these populations of feral colonies. We estimated the mating frequencies of queens in feral colonies in the Arnot Forest in New York State to determine if the level of polyandry of these queens is especially high and so might contribute to their survival success. We genotyped the worker offspring from 10 feral colonies in the Arnot Forest of upstate New York, as well as those from 20 managed colonies closest to this forest. We found no significant differences in mean mating frequency between the feral and managed queens, suggesting that queens in the remote, low-density population of colonies in the Arnot Forest are neither mate-limited nor adapted to mate at an especially high frequency. These findings support the hypothesis that the hyperpolyandry of honey bees has been shaped on an evolutionary timescale rather than on an ecological one.

The density of feral honey bee (Apis mellifera) colonies in South East Australia is greater in undisturbed than in disturbed habitats

Apis mellifera is an important pollinator but is sometimes associated with adverse effects on natural ecosystems. We surveyed pairs of disturbed and undisturbed sites across three biomes in South East Australia. We used pheromone lures to trap drones, genotyped the drones to infer the number of colonies within flight range and then estimated colony densities using synthetic sampling distributions. Estimated colony densities ranged from 0.1 to 1.5 colonies km−2 and significantly lower in agricultural land relative to national parks. We suggest that colony density may be lower in disturbed than ‘natural’ areas due to the reduced availability of nest sites and possibly pesticide usage. Because the number of colonies recommended for adequate pollination is 100–1000 colonies km−2, there are insufficient bees to provide optimal crop pollination in the areas we surveyed.

Remarkable uniformity in the densities of feral honey bee Apis mellifera Linnaeus, 1758 (Hymenoptera: Apidae) colonies in South Eastern Australia

AbstractIt is often assumed that the density of feral honey bee colonies in Australia is sufficient to provide adequate pollination services to the many agricultural crops that require pollination. In contrast, there is concern that the density of feral colonies is sufficiently high to have inimical effects on Australian biota. For both these reasons, it is desirable to have robust estimates of the density of feral honey bee colonies in Australian landscapes. In this study, we mated four to five queens with wild drones at disturbed and undisturbed sites in three of the major ecosystems in Victoria Australia and examined the paternities of worker offspring to estimate the density of feral colonies within mating range of the test queens. We show that the density of feral colonies differs little with land use (cleared or uncleared) and is similar across the state. Our data suggest that the density of feral colonies is probably insufficient to provide adequate pollination of agricultural crops and that neither land use nor local climate variation is a major factor determining density. Finally, our data suggest that the mating range sampled by test queens is significantly greater than previously assumed.

There are still Bee Trees in Europe

In Europe honey bees are considered as domesticated animals. Beekeepers provide them with hives, feed them, protect against parasites and manage them extensively. However, the number of colonies in central and northern Europe is declining, Feral colonies of honey bees once present in Europe have also seen a sharp decline in recent years.

Diurnal patterns of pollen collection by feral honey bee colonies in southern Texas, USA

Honey bees (Apis mellifera L.) collect pollen for brood and young worker development, and pollinate many crops and economically important plants. Pollen was collected from honey bees from six feral honey bee colonies in southern Texas during two time periods to evaluate diurnal patterns of pollen collection. Overall, the same pollen types tended to be collected throughout the day, however, the percentages differed depending upon the time of day. Honey bees from four of the six colonies collected predominant pollen types (> 45% of a sample). Honey bees from the two colonies which did not collect a predominant pollen type collected two or more secondary pollen types (16–45% of a sample). Lamiaceae was the most prevalent pollen type collected during the early sampling period and an unknown tricolporate grain was the most collected pollen type during the late sampling period. However, honey bees from one colony primarily collected the unknown tricolporate grain during both sampling periods. Several factors probably contributed to these diurnal variations in pollen collection patterns. These include floral patterns of pollen availability, resource depletion and/or profitability, nutritional needs of honey bees and preferences of individual honey bee foragers.

Destroying managed and feral honey bee (Apis mellifera) colonies to eradicate honey bee pests

This paper reports on trials conducted to kill managed and feral honey bee (Apis mellifera) colonies to eradicate unwanted honey bee pests. The effectiveness of Pestigas‐P™ (natural pyrethrum) for the destruction of managed colonies was assessed. Pestigas‐P™ was effective when applied as a single 15‐s spray into an empty three‐quarter‐depth super and across the top of the frames. This allowed the gas to filter throughout the hive. Piperonyl butoxide (wax = 42.28 mg/kg, honey = 0.34 mg/kg, propolis = 9.2 mg/kg, floor scrapings = 270.34 mg/kg) and pyrethrum (wax = 21.3 mg/kg, honey = 0.06 mg/ kg, propolis = 6.8 mg/kg, floor scrapings = 172.4 mg/kg) residues were found in the hive but after 4 weeks these had no detectable effect on newly introduced honey bee colonies. Combined analyses of attractiveness, toxicity, and lethal time trials identified Ascend® 200SC (a.i. fipronil) as effective for depopulating feral honey bee colonies in New Zealand using poisoned baits. Ascend® 200SC is a slow acting stomach toxin. The effect of Ascend® on feral honey bee colonies was assessed in Canterbury, New Zealand in 2003. Nucleus colonies were placed between bait stations set out in a 4km2 grid. The stations were pre‐baited with sugar syrup which was replaced with sugar syrup containing fipronil (0.05 ml/litre) once 300 bees were foraging from a single bait station. In the autumn trial all 20 colonies died within 13 days of poisoning. After 6 weeks the effect of poisoned hives on the survival of newly introduced colonies was assessed. Five colonies were placed next to 10 poisoned hives in the original eradication area, five colonies were placed with 10 poisoned hives at least 4km from the original area, and an additional 10 colonies were placed at least 4km from the original area and 4 km apart. Introduced colonies are likely to die if they consume the stored fipronil in poisoned colonies. This persistent poisoning action increases the likelihood of a honey bee eradication attempt being successful, as the colonies that are not killed in the first round of poisoning may be poisoned by robbing honey containing fipronil from a previously poisoned hive. Fipronil remained toxic in honey for at least 26 months when stored at 0°C, 5°C, and 25°C.

Honey bees of the Arnot Forest: a population of feral colonies persisting withVarroa destructorin the northeastern United States

Feral colonies of European honey bees living in the Arnot Forest, a 1651-ha research preserve in New York State, were studied over a three-year period, 2002 to 2005. This population of colonies was previously censused in 1978. A census in 2002 revealed as many colonies as before, even though Varroa destructor was introduced to North America in the intervening years. Most colonies located in fall 2002 were still alive in fall 2005. The Arnot Forest colonies proved to be infested with V. destructor, but their mite populations did not surge to high levels in late summer. To see if Arnot Forest bees can suppress the reproduction rate of mites, colonies of Arnot Forest bees and New World Carniolan bees were inoculated with mites from an apiary and the growth patterns of their mite populations were compared. No difference was found between the two colony types. Evidently, the stable bee-mite relationship in the Arnot Forest reflects adaptations for parasite (mite) avirulence, not host (bee) resistance.

Spatial and Temporal Distribution and Nest Site Characteristics of Feral Honey Bee (Hymenoptera: Apidae) Colonies in a Coastal Prairie Landscape

We evaluated the distribution and abundance of feral honey bee, Apis mellifera L., colonies in a coastal prairie landscape by examining nest site characteristics, population trends, and spatial and temporal patterns in cavity use. The colony densities of up to 12.5 colonies per km2 were the highest reported in the literature for an area including both suitable and unsuitable patches of nesting habitat. The measured cavity attributes were similar to those reported from other areas. The time occupied and turnover indices provided useful information about cavity quality, although none of the measured cavity attributes were correlated with these indices. Unmeasurable cavity characteristics, such as cavity volume, may provide a better estimate of cavity quality. Spatial patterns existed in cavity use by the feral colonies, with the colonies showing an aggregated pattern of distribution throughout the study. Colony aggregations probably resulted from the distribution of resources, especially cavities. Two years after the arrival of Africanized honey bees, cavities used by Africanized and European colonies were aggregated in distribution. During what seemed to be a transition period, both Africanized and European colonies were randomly distributed. After that time, European colonies remained randomly distributed, whereas Africanized colonies were aggregated. Therefore, the invasion of Africanized honey bees seemed to fragment the existing European population, corresponding to a decrease in the overall number of European colonies in the study area.