Bumble bees in landscapes with abundant floral resources have lower pathogen loads

AbstractThe pollination services provided by bees are essential for supporting natural and agricultural ecosystems. However, bee population declines have been documented across the world. Many of the factors known to undermine bee health (e.g., poor nutrition) can decrease immunocompetence and, thereby, increase bees’ susceptibility to diseases. Given the myriad of stressors that can exacerbate disease in wild bee populations, assessments of the relative impact of landscape habitat conditions on bee pathogen prevalence are needed to effectively conserve pollinator populations. Herein, we assess how landscape-level conditions, including various metrics of floral/nesting resources, insecticides, weather, and honey bee (Apis mellifera) abundance, drive variation in wild bumble bee (Bombus impatiens) pathogen loads. Specifically, we screened 890 bumble bee workers from varied habitats in Pennsylvania, USA for three pathogens (deformed wing virus, black queen cell virus, and Vairimorpha (= Nosema) bombi), Defensin expression, and body size. Bumble bees collected within low-quality landscapes exhibited the highest pathogen loads, with spring floral resources and nesting habitat availability serving as the main drivers. We also found higher loads of pathogens where honey bee apiaries are more abundant, a positive relationship between Vairimorpha loads and rainfall, and differences in pathogens by geographic region. Collectively, our results highlight the need to support high-quality landscapes (i.e., those with abundant floral/nesting resources) to maintain healthy wild bee populations.

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Impact of Chronic Exposure to Sublethal Doses of Glyphosate on Honey Bee Immunity, Gut Microbiota and Infection by Pathogens

Microorganisms ◽

10.3390/microorganisms9040845 ◽

2021 ◽

Vol 9 (4) ◽

pp. 845

Author(s):

Loreley Castelli ◽

Sofía Balbuena ◽

Belén Branchiccela ◽

Pablo Zunino ◽

Joanito Liberti ◽

...

Keyword(s):

Gut Microbiota ◽

Honey Bee ◽

Chronic Exposure ◽

Pollination Services ◽

Deformed Wing Virus ◽

Immune Genes ◽

Bee Health ◽

Honey Bee Health ◽

Sublethal Doses ◽

The Impact

Glyphosate is the most used pesticide around the world. Although different studies have evidenced its negative effect on honey bees, including detrimental impacts on behavior, cognitive, sensory and developmental abilities, its use continues to grow. Recent studies have shown that it also alters the composition of the honey bee gut microbiota. In this study we explored the impact of chronic exposure to sublethal doses of glyphosate on the honey bee gut microbiota and its effects on the immune response, infection by Nosema ceranae and Deformed wing virus (DWV) and honey bee survival. Glyphosate combined with N. ceranae infection altered the structure and composition of the honey bee gut microbiota, for example by decreasing the relative abundance of the core members Snodgrassella alvi and Lactobacillus apis. Glyphosate increased the expression of some immune genes, possibly representing a physiological response to mitigate its negative effects. However, this response was not sufficient to maintain honey bee health, as glyphosate promoted the replication of DWV and decreased the expression of vitellogenin, which were accompanied by a reduced life span. Infection by N. ceranae also alters honey bee immunity although no synergistic effect with glyphosate was observed. These results corroborate previous findings suggesting deleterious effects of widespread use of glyphosate on honey bee health, and they contribute to elucidate the physiological mechanisms underlying a global decline of pollination services.

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First Complete Genome of Lake Sinai Virus Lineage 3 and Genetic Diversity of Lake Sinai Virus Strains From Honey Bees and Bumble Bees

Journal of Economic Entomology ◽

10.1093/jee/toaa049 ◽

2020 ◽

Vol 113 (3) ◽

pp. 1055-1061 ◽

Cited By ~ 1

Author(s):

Laura Šimenc ◽

Urška Kuhar ◽

Urška Jamnikar-Ciglenečki ◽

Ivan Toplak

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Complete Genome ◽

Bumble Bees ◽

Bumble Bee ◽

Rt Pcr ◽

Genome Region ◽

Pcr Method ◽

Next Generation Sequencing Ngs ◽

First Time

Abstract The complete genome of Lake Sinai virus 3 (LSV3) was sequenced by the Ion Torrent next-generation sequencing (NGS) technology from an archive sample of honey bees collected in 2010. This strain M92/2010 is the first complete genome sequence of LSV lineage 3. From October 2016 to December 2017, 56 honey bee samples from 32 different locations and 41 bumble bee samples from five different locations were collected. These samples were tested using a specific reverse transcriptase-polymerase chain reaction (RT-PCR) method; 75.92% of honey bee samples and 17.07% of bumble bee samples were LSV-positive with the RT-PCR method. Phylogenetic comparison of 557-base pair-long RNA-dependent RNA polymerase (RdRp) genome region of selected 23 positive samples of honey bees and three positive bumble bee samples identified three different LSV lineages: LSV1, LSV2, and LSV3. The LSV3 lineage was confirmed for the first time in Slovenia in 2010, and the same strain was later detected in several locations within the country. The LSV strains detected in bumble bees are from 98.6 to 99.4% identical to LSV strains detected among honey bees in the same territory.

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Why Are Queens Broodless? Failed Nest Initiation Not Linked to Parasites, Mating Status, or Ovary Development in Two Bumble Bee Species of Pyrobombus (Hymenoptera: Apidae: Bombus)

Journal of Economic Entomology ◽

10.1093/jee/toz330 ◽

2019 ◽

Vol 113 (2) ◽

pp. 575-581 ◽

Cited By ~ 1

Author(s):

Jessica L Mullins ◽

James P Strange ◽

Amber D Tripodi

Keyword(s):

North America ◽

Commercial Production ◽

Bumble Bees ◽

Ovary Development ◽

Bumble Bee ◽

Agricultural Crops ◽

Western North America ◽

Mating Status ◽

Pollination Services ◽

Causal Factors

Abstract Bumble bees (Bombus [Hymenoptera: Apidae]) are important pollinators for agricultural crops, which has led to their commercial domestication. Despite their importance, little is known about the reproductive biology of bumble bees native to North America. The Hunt bumble bee (Bombus huntii Greene [Hymenoptera: Apidae]) and the Vosnesensky bumble bee (Bombus vosnesenskii Radoszkowski [Hymenoptera: Apidae] are native candidates for commercial production in western North America due to their efficacy in providing commercial pollination services. Availability of pollinators native to the region in which services would be provided would minimize the likelihood of introducing exotic species and spreading novel disease. Some parasites are known to affect bumble bee reproduction, but little is known about their prevalence in North America or how they affect queen success. Only 38% of wild-caught B. huntii and 51% wild-caught B. vosnesenskii queens collected between 2015 and 2017 initiated nests in the laboratory. Our objective was to identify causal factors leading to a queen’s inability to oviposit. To address this, we dissected each broodless queen and diagnosed diseases, assessed mating status, and characterized ovary development. Nematodes, arthropods, and microorganisms were detected in both species. Overall, 20% of queens were infected by parasites, with higher rates in B. vosnesenskii. Over 95% of both species were mated, and over 88% had developed ovaries. This suggests that parasitism and mating status were not primary causes of broodlessness. Although some failure to nest can be attributed to assessed factors, additional research is needed to fully understand the challenges presented by captive rearing.

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Diversity, density, efficiency, and effectiveness of pollinators of cicer milkvetch, Astragalus cicer L.

Canadian Journal of Zoology ◽

10.1139/z87-331 ◽

1987 ◽

Vol 65 (9) ◽

pp. 2168-2176 ◽

Cited By ~ 18

Author(s):

K. W. Richards

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Propagation Rate ◽

Bumble Bees ◽

Bumble Bee ◽

Bee Pollination ◽

Southern Alberta ◽

Efficiency And Effectiveness ◽

Astragalus Cicer

Diversity, density, efficiency, and effectiveness of pollinators of cicer milkvetch, Astragalus cicer L., grown at two locations in southern Alberta were studied from 1978 to 1983. Twenty-seven species of bees were identified as pollinators. At Lethbridge, honey bees (Apis mellifera) comprised 74% of the observations, bumble bees 16%, and leafcutter bees 10%, while at Spring Coulee, the proportions were honey bees 14%, bumble bees 69%, and leafcutter bees 17%. The rate of foraging by pollinator species from flower to flower varied; bumble bee species, especially Bombus nevadensis Cress., foraged consistently more efficiently than honey bees or alfalfa leafcutter bees, Megachile rotundata (F.). A theoretical approach used to predict the bee populations required to pollinate varying flower densities shows that the population of B. nevadensis required is about half those of Bombus huntii Greene and M. rotundata and less than one-quarter that of the honey bee. Pollination by B. nevadensis consistently resulted in more seeds per pod than with any other bumble bee species, the honey bee, or M. rotundata. Of the nine species of bumble bee that established colonies in artificial domiciles near the field, B. nevadensis established the most colonies each year. The number of workers and sexuals produced per colony varied considerably among bumble bee species with only 55% of the colony establishments producing workers and 31% producing sexuals. The propagation rate and quality of alfalfa leafcutter bees produced on cicer milkvetch was excellent.

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Deformed Wing Virus in Two Widespread Invasive Ants: Geographical Distribution, Prevalence, and Phylogeny

Viruses ◽

10.3390/v12111309 ◽

2020 ◽

Vol 12 (11) ◽

pp. 1309

Author(s):

Chun-Yi Lin ◽

Chih-Chi Lee ◽

Yu-Shin Nai ◽

Hung-Wei Hsu ◽

Chow-Yang Lee ◽

...

Keyword(s):

Geographical Distribution ◽

Honey Bee ◽

Distribution Patterns ◽

Transmission Efficiency ◽

Reservoir Host ◽

Asia Pacific ◽

Invasive Ants ◽

Pollination Services ◽

Deformed Wing Virus ◽

Bee Viruses

Spillover of honey bee viruses have posed a significant threat to pollination services, triggering substantial effort in determining the host range of the viruses as an attempt to understand the transmission dynamics. Previous studies have reported infection of honey bee viruses in ants, raising the concern of ants serving as a reservoir host. Most of these studies, however, are restricted to a single, local ant population. We assessed the status (geographical distribution/prevalence/viral replication) and phylogenetic relationships of honey bee viruses in ants across the Asia–Pacific region, using deformed wing virus (DWV) and two widespread invasive ants, Paratrechina longicornis and Anoplolepis gracilipes, as the study system. DWV was detected in both ant species, with differential geographical distribution patterns and prevenance levels between them. These metrics, however, are consistent across the geographical range of the same ant species. Active replication was only evident in P. longicornis. We also showed that ant-associated DWV is genetically similar to that isolated from Asian populations of honey bees, suggesting that local acquisition of DWV by the invasive ants may have been common at least in some of our sampled regions. Transmission efficiency of DWV to local arthropods mediated by ant, however, may vary across ant species.

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Diversity and Global Distribution of Viruses of the Western Honey Bee, Apis mellifera

Insects ◽

10.3390/insects11040239 ◽

2020 ◽

Vol 11 (4) ◽

pp. 239 ◽

Cited By ~ 13

Author(s):

Alexis Beaurepaire ◽

Niels Piot ◽

Vincent Doublet ◽

Karina Antunez ◽

Ewan Campbell ◽

...

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

High Throughput Sequencing ◽

Temporal Dynamics ◽

Pollination Services ◽

Colony Losses ◽

New Host ◽

Deformed Wing Virus ◽

Bee Colony ◽

Queen Cell

In the past centuries, viruses have benefited from globalization to spread across the globe, infecting new host species and populations. A growing number of viruses have been documented in the western honey bee, Apis mellifera. Several of these contribute significantly to honey bee colony losses. This review synthetizes the knowledge of the diversity and distribution of honey-bee-infecting viruses, including recent data from high-throughput sequencing (HTS). After presenting the diversity of viruses and their corresponding symptoms, we surveyed the scientific literature for the prevalence of these pathogens across the globe. The geographical distribution shows that the most prevalent viruses (deformed wing virus, sacbrood virus, black queen cell virus and acute paralysis complex) are also the most widely distributed. We discuss the ecological drivers that influence the distribution of these pathogens in worldwide honey bee populations. Besides the natural transmission routes and the resulting temporal dynamics, global trade contributes to their dissemination. As recent evidence shows that these viruses are often multihost pathogens, their spread is a risk for both the beekeeping industry and the pollination services provided by managed and wild pollinators.

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Diversified Farming in a Monoculture Landscape: Effects on Honey Bee Health and Wild Bee Communities

Environmental Entomology ◽

10.1093/ee/nvaa031 ◽

2020 ◽

Vol 49 (3) ◽

pp. 753-764 ◽

Cited By ~ 1

Author(s):

Ashley L St. Clair ◽

Ge Zhang ◽

Adam G Dolezal ◽

Matthew E O’Neal ◽

Amy L Toth

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Natural Habitat ◽

Colony Growth ◽

Nutritional State ◽

Floral Resources ◽

Fruit And Vegetable ◽

Wild Bee ◽

Bee Conservation ◽

Bee Communities

Abstract In the last century, a global transformation of Earth’s surface has occurred due to human activity with extensive agriculture replacing natural ecosystems. Concomitant declines in wild and managed bees are occurring, largely due to a lack of floral resources and inadequate nutrition, caused by conversion to monoculture-based farming. Diversified fruit and vegetable farms may provide an enhanced variety of resources through crops and weedy plants, which have potential to sustain human and bee nutrition. We hypothesized fruit and vegetable farms can enhance honey bee (Hymenoptera: Apidae, Apis mellifera Linnaeus) colony growth and nutritional state over a soybean monoculture, as well as support a more diverse wild bee community. We tracked honey bee colony growth, nutritional state, and wild bee abundance, richness, and diversity in both farm types. Honey bees kept at diversified farms had increased colony weight and preoverwintering nutritional state. Regardless of colony location, precipitous declines in colony weight occurred during autumn and thus colonies were not completely buffered from the stressors of living in a matrix dominated with monocultures. Contrary to our hypothesis, wild bee diversity was greater in soybean, specifically in August, a time when fields are in bloom. These differences were largely driven by four common bee species that performed well in soybean. Overall, these results suggest fruit and vegetable farms provide some benefits for honey bees; however, they do not benefit wild bee communities. Thus, incorporation of natural habitat, rather than diversified farming, in these landscapes, may be a better choice for wild bee conservation efforts.

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Using Commercial Bumble Bee Colonies as Backup Pollinators for Honey Bees to Produce Cucumbers and Watermelons

HortTechnology ◽

10.21273/horttech.8.4.590 ◽

1998 ◽

Vol 8 (4) ◽

pp. 590-594 ◽

Cited By ~ 15

Author(s):

M.S. Stanghellini ◽

J.T. Ambrose ◽

J.R. Schultheis

Keyword(s):

Honey Bee ◽

Honey Bees ◽

Seed Set ◽

Citrullus Lanatus ◽

Bumble Bees ◽

Bumble Bee ◽

Insect Visitation ◽

Parasitic Mite ◽

Fruit Abortion ◽

Bee Colonies

The effectiveness of bumble bees, Bombus impatiens Cresson, and honey bees, Apis mellifera L., on the pollination of cucumber, Cucumis sativus L., and watermelon, Citrullus lanatus (Thunb.) Matsum. & Nakai, was compared under field conditions. Comparisons were based on fruit abortion rates and seed set as influenced by bee type (honey bee or bumble bee) and the number of bee visits to treatment flowers (1, 6, 12, and 18 bee visits), plus two controls: a no-visit treatment and an open-pollinated (unrestricted visitation) treatment. For both crops, an increased number of bee visits had a strong positive effect on fruit and seed set. All cucumber and watermelon flowers bagged to prevent insect visitation aborted, demonstrating the need for active transfer of pollen between staminate and pistillate flowers. Bumble bee-visited flowers consistently had lower abortion rates and higher seed sets in the cucumber and watermelon studies than did honey bee-visited flowers when compared at the same bee visitation level. Only slight differences in fruit abortion rates were detected between bee types in the watermelon study. However, abortion rates for bumble bee-visited flowers were consistently less than those for honey bee-visited flowers when compared at equal bee visitation levels, with one exception at the 12 bee visit level. As the number of honey bee colonies continues to decline due to parasitic mite pests and based on the data obtained, we conclude that bumble bees have a great potential to serve as a supplemental pollinator for cucumbers, watermelons, and possibly other vine crops, when honey bees available for rental are in limited supply.

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Multi-tiered Analyses of Honey Bees That Resist or Succumb to Parasitic Mites and Viruses

10.21203/rs.3.rs-291062/v1 ◽

2021 ◽

Author(s):

Daniel B. Weaver ◽

Brandi L. Cantarel ◽

Christine Elsik ◽

Dawn L. Lopez ◽

Jay Evans

Keyword(s):

Gene Expression ◽

Honey Bee ◽

Honey Bees ◽

Host Responses ◽

Negative Effects ◽

Pollination Services ◽

Deformed Wing Virus ◽

Mortality And Morbidity ◽

The Individual ◽

Parasitic Mites

Abstract Background Varroa destructor mites, and the numerous viruses they vector to their honey bee hosts, are among the most serious threats to honey bee populations, causing mortality and morbidity to both the individual honey bee and colony, the negative effects of which convey to the pollination services provided by honey bees worldwide. Here we use a combination of targeted assays and deep RNA sequencing to determine host and microbial changes in resistant and susceptible honey bee lineages. We focus on three study sets. The first involves field sampling of sympatric western bees, some derived from resistant stock and some from stock susceptible to mites. The second experiment contrasts three colonies more deeply, two from susceptible stock from the southeastern U.S. and one from mite-resistant bee stock from Eastern Texas. Finally, to decouple the effects of mites from those of the viruses they vector, we experimentally expose honey bees to DWV in the laboratory, measuring viral growth and host responses. Results We find strong differences between resistant and susceptible bees in terms of both viral loads and bee gene expression. Interestingly, lineages of bees with naturally low levels of the mite-vectored Deformed wing virus, also carried lower levels of viruses not vectored by mites. By mapping gene expression results against current ontologies and other studies, we describe the impacts of mite parasitism, as well as viruses on bee health against two genetic backgrounds. We identify numerous genes and processes seen in other studies of stress and disease in honey bee colonies, though we find novel genes and new patterns of expression too. Conclusions We provide evidence that honey bees surviving in the face of parasitic mites do so through their abilities to resist the presence of devastating viruses vectored by these mites. By revealing responses to viral infection and mite parasitism in different lineages, our data identify candidate proteins for the evolution of mite tolerance and virus resistance.

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Cross-infectivity of honey and bumble bee-associated parasites across three bee families

Parasitology ◽

10.1017/s0031182020001018 ◽

2020 ◽

Vol 147 (12) ◽

pp. 1290-1304 ◽

Cited By ~ 1

Author(s):

Lyna Ngor ◽

Evan C. Palmer-Young ◽

Rodrigo Burciaga Nevarez ◽

Kaleigh A. Russell ◽

Laura Leger ◽

...

Keyword(s):

Experimental Tests ◽

Bumble Bees ◽

Floral Resources ◽

Bumble Bee ◽

Broad Host Range ◽

Osmia Lignaria ◽

Social Bees ◽

Crithidia Bombi ◽

Halictus Ligatus ◽

Parasite Replication

AbstractRecent declines of wild pollinators and infections in honey, bumble and other bee species have raised concerns about pathogen spillover from managed honey and bumble bees to other pollinators. Parasites of honey and bumble bees include trypanosomatids and microsporidia that often exhibit low host specificity, suggesting potential for spillover to co-occurring bees via shared floral resources. However, experimental tests of trypanosomatid and microsporidial cross-infectivity outside of managed honey and bumble bees are scarce. To characterize potential cross-infectivity of honey and bumble bee-associated parasites, we inoculated three trypanosomatids and one microsporidian into five potential hosts – including four managed species – from the apid, halictid and megachilid bee families. We found evidence of cross-infection by the trypanosomatids Crithidia bombi and C. mellificae, with evidence for replication in 3/5 and 3/4 host species, respectively. These include the first reports of experimental C. bombi infection in Megachile rotundata and Osmia lignaria, and C. mellificae infection in O. lignaria and Halictus ligatus. Although inability to control amounts inoculated in O. lignaria and H. ligatus hindered estimates of parasite replication, our findings suggest a broad host range in these trypanosomatids, and underscore the need to quantify disease-mediated threats of managed social bees to sympatric pollinators.

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