Combined impacts of viral pathogens and pesticides on bumble bee health

2016 ◽  
Author(s):  
Diana Cox-Foster
Keyword(s):  
Bumble Bee ◽  
Viral Pathogens ◽  
Bee Health

Bee Viruses: Ecology, Pathogenicity, and Impacts

2019 ◽  
Vol 64 (1) ◽  
pp. 205-226 ◽  
Author(s):  
Christina M. Grozinger ◽  
Michelle L. Flenniken
Keyword(s):  
Management Strategies ◽  
Flowering Plant ◽  
Virus Infections ◽  
Viral Pathogens ◽  
Viral Ecology ◽  
Bee Health ◽  
Ecological Importance ◽  
Complex Relationships ◽  
Flowering Plant Species ◽  
Poor Nutrition

Bees—including solitary, social, wild, and managed species—are key pollinators of flowering plant species, including nearly three-quarters of global food crops. Their ecological importance, coupled with increased annual losses of managed honey bees and declines in populations of key wild species, has focused attention on the factors that adversely affect bee health, including viral pathogens. Genomic approaches have dramatically expanded understanding of the diversity of viruses that infect bees, the complexity of their transmission routes—including intergenus transmission—and the diversity of strategies bees have evolved to combat virus infections, with RNA-mediated responses playing a prominent role. Moreover, the impacts of viruses on their hosts are exacerbated by the other major stressors bee populations face, including parasites, poor nutrition, and exposure to chemicals. Unraveling the complex relationships between viruses and their bee hosts will lead to improved understanding of viral ecology and management strategies that support better bee health.

Global Trends in Bumble Bee Health

2020 ◽  
Vol 65 (1) ◽  
pp. 209-232 ◽  
Author(s):  
Sydney A. Cameron ◽  
Ben M. Sadd
Keyword(s):  
Wild Species ◽  
Population Decline ◽  
Pathogen Transmission ◽  
Sub Saharan Africa ◽  
Bumble Bee ◽  
Population Declines ◽  
Natural Ecosystems ◽  
Threat Status ◽  
Bee Health ◽  
Biogeographic Regions

Bumble bees ( Bombus) are unusually important pollinators, with approximately 260 wild species native to all biogeographic regions except sub-Saharan Africa, Australia, and New Zealand. As they are vitally important in natural ecosystems and to agricultural food production globally, the increase in reports of declining distribution and abundance over the past decade has led to an explosion of interest in bumble bee population decline. We summarize data on the threat status of wild bumble bee species across biogeographic regions, underscoring regions lacking assessment data. Focusing on data-rich studies, we also synthesize recent research on potential causes of population declines. There is evidence that habitat loss, changing climate, pathogen transmission, invasion of nonnative species, and pesticides, operating individually and in combination, negatively impact bumble bee health, and that effects may depend on species and locality. We distinguish between correlational and causal results, underscoring the importance of expanding experimental research beyond the study of two commercially available species to identify causal factors affecting the diversity of wild species.

scholarly journals Co-formulant in a commercial fungicide product causes lethal and sub-lethal effects in bumble bees

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Edward A. Straw ◽  
Mark J. F. Brown
Keyword(s):  
Sublethal Effects ◽  
Negative Control ◽  
Alcohol Ethoxylates ◽  
Bumble Bee ◽  
Active Ingredients ◽  
Wild Bees ◽  
Pesticide Formulations ◽  
Bee Health ◽  
Gut Damage ◽  
Commercial Fungicide

AbstractPollinators, particularly wild bees, are suffering declines across the globe, and pesticides are thought to be drivers of these declines. Research into, and regulation of pesticides has focused on the active ingredients, and their impact on bee health. In contrast, the additional components in pesticide formulations have been overlooked as potential threats. By testing an acute oral dose of the fungicide product Amistar, and equivalent doses of each individual co-formulant, we were able to measure the toxicity of the formulation and identify the ingredient responsible. We found that a co-formulant, alcohol ethoxylates, caused a range of damage to bumble bee health. Exposure to alcohol ethoxylates caused 30% mortality and a range of sublethal effects. Alcohol ethoxylates treated bees consumed half as much sucrose as negative control bees over the course of the experiment and lost weight. Alcohol ethoxylates treated bees had significant melanisation of their midguts, evidence of gut damage. We suggest that this gut damage explains the reduction in appetite, weight loss and mortality, with bees dying from energy depletion. Our results demonstrate that sublethal impacts of pesticide formulations need to be considered during regulatory consideration, and that co-formulants can be more toxic than active ingredients.

scholarly journals No evidence of effects or interaction between the widely used herbicide, glyphosate, and a common parasite in bumble bees

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12486
Author(s):  
Edward A. Straw ◽  
Mark J.F. Brown
Keyword(s):  
Chronic Exposure ◽  
Multiple Stressors ◽  
Bombus Terrestris ◽  
Bumble Bees ◽  
Acute Exposure ◽  
Bumble Bee ◽  
Term Survival ◽  
Crithidia Bombi ◽  
Bee Health ◽  
Acute And Chronic Exposure

Background Glyphosate is the world’s most used pesticide and it is used without the mitigation measures that could reduce the exposure of pollinators to it. However, studies are starting to suggest negative impacts of this pesticide on bees, an essential group of pollinators. Accordingly, whether glyphosate, alone or alongside other stressors, is detrimental to bee health is a vital question. Bees are suffering declines across the globe, and pesticides, including glyphosate, have been suggested as being factors in these declines. Methods Here we test, across a range of experimental paradigms, whether glyphosate impacts a wild bumble bee species, Bombus terrestris. In addition, we build upon existing work with honey bees testing glyphosate-parasite interactions by conducting fully crossed experiments with glyphosate and a common bumble bee trypanosome gut parasite, Crithidia bombi. We utilised regulatory acute toxicity testing protocols, modified to allow for exposure to multiple stressors. These protocols are expanded upon to test for effects on long term survival (20 days). Microcolony testing, using unmated workers, was employed to measure the impacts of either stressor on a proxy of reproductive success. This microcolony testing was conducted with both acute and chronic exposure to cover a range of exposure scenarios. Results We found no effects of acute or chronic exposure to glyphosate, over a range of timespans post-exposure, on mortality or a range of sublethal metrics. We also found no interaction between glyphosate and Crithidia bombi in any metric, although there was conflicting evidence of increased parasite intensity after an acute exposure to glyphosate. In contrast to published literature, we found no direct impacts of this parasite on bee health. Our testing focussed on mortality and worker reproduction, so impacts of either or both of these stressors on other sublethal metrics could still exist. Conclusions Our results expand the current knowledge on glyphosate by testing a previously untested species, Bombus terrestris, using acute exposure, and by incorporating a parasite never before tested alongside glyphosate. In conclusion our results find that glyphosate, as an active ingredient, is unlikely to be harmful to bumble bees either alone, or alongside Crithidia bombi.

The Diagnosis of Viral Disease by Electron Microscopy

1982 ◽  
Vol 40 ◽  
pp. 270-273
Author(s):  
William B. McCombs ◽  
Cameron E. McCoy
Keyword(s):  
Electron Microscopy ◽  
Hospital Stay ◽  
Viral Infections ◽  
Medical Profession ◽  
Bacterial Pathogens ◽  
Viral Disease ◽  
Viral Pathogens ◽  
Academic Interest ◽  
The Past

Recent years have brought a reversal in the attitude of the medical profession toward the diagnosis of viral infections. Identification of bacterial pathogens was formerly thought to be faster than identification of viral pathogens. Viral identification was dismissed as being of academic interest or for confirming the presence of an epidemic, because the patient would recover or die before this could be accomplished. In the past 10 years, the goal of virologists has been to present the clinician with a viral identification in a matter of hours. This fast diagnosis has the potential for shortening the patient's hospital stay and preventing the administering of toxic and/or expensive antibiotics of no benefit to the patient.

Parasite defense mechanisms in bees: behavior, immunity, antimicrobials, and symbionts

2019 ◽  
Vol 4 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Alison E. Fowler ◽  
Rebecca E. Irwin ◽  
Lynn S. Adler
Keyword(s):  
Defense Mechanisms ◽  
Poor Quality ◽  
Future Research ◽  
Immune Priming ◽  
Social Bees ◽  
Bee Health ◽  
Landscape Scales ◽  
And Function ◽  
Solitary Species

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.

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