Honey bee queen health is unaffected by contact exposure to pesticides commonly found in beeswax

AbstractHoney bee queen health is crucial for colony health and productivity, and pesticides have been previously associated with queen loss and premature supersedure. Prior research has investigated the effects of indirect pesticide exposure on queens via workers, as well as direct effects on queens during development. However, as adults, queens are in constant contact with wax as they walk on comb and lay eggs; therefore, direct pesticide contact with adult queens is a relevant but seldom investigated exposure route. Here, we conducted laboratory and field experiments to investigate the impacts of topical pesticide exposure on adult queens. We tested six pesticides commonly found in wax: coumaphos, tau-fluvalinate, atrazine, 2,4-DMPF, chlorpyriphos, chlorothalonil, and a cocktail of all six, each administered at 1, 4, 8, 16, and 32 times the concentrations typically found in wax. We found no effect of any treatment on queen mass, sperm viability, or fat body protein expression. In a field trial testing queen topical exposure of a pesticide cocktail, we found no impact on egg-laying pattern, queen mass, emergence mass of daughter workers, and no proteins in the spermathecal fluid were differentially expressed. These experiments consistently show that pesticides commonly found in wax have no direct impact on queen performance, reproduction, or quality metrics at the doses tested. We suggest that previously reported associations between high levels of pesticide residues in wax and queen failure are most likely driven by indirect effects of worker exposure (either through wax or other hive products) on queen care or queen perception.

Download Full-text

Honey bee queen health is unaffected by contact exposure to pesticides commonly found in beeswax

10.1101/2021.04.24.441288 ◽

2021 ◽

Author(s):

Alison McAfee ◽

Joseph P Milone ◽

Erin McDermott ◽

Bradley Metz ◽

Leonard Foster ◽

...

Keyword(s):

Honey Bee ◽

Field Experiments ◽

Pesticide Exposure ◽

Egg Laying ◽

Differentially Expressed ◽

Contact Exposure ◽

Solvent Control ◽

Honey Bee Queen ◽

Exposure Levels ◽

Fat Bodies

Honey bee queen health is crucial for colony health and productivity, and pesticides have been previously associated with queen loss and premature supersedure. Prior research has investigated the effects of indirect pesticide exposure on queens via workers, as well as direct effects on queens during development. However, as adults, queens are in constant contact with wax as they walk on comb and lay eggs; therefore, direct pesticide contact with adult queens is a relevant but seldom investigated exposure route. Here, we conducted laboratory and field experiments to investigate the impacts of topical pesticide exposure on adult queens. We tested dose-response relationships of six pesticides commonly found in wax: coumaphos, tau-fluvalinate, atrazine, 2,4-DMPF, chlorpyriphos, chlorothalonil, and a cocktail of all six, each dosed up to 32 times the concentrations typically found in wax. We found no effect of any treatment on queen mass or sperm viability. Furthermore, none of the 1,568 proteins quantified in the queens' fat bodies (a major site of detoxification enzyme production) were differentially expressed. In a field trial with N = 30 queens exposed to either a handling control, a solvent control, or a pesticide cocktail, we again found no impact on queen egg-laying pattern, mass, or emergence mass of daughter workers. Further, of the 3,127 proteins identified in fluid from the spermatheca (sperm storage organ), none were differentially expressed. These experiments consistently show that at realistic exposure levels, pesticides commonly found in wax have no direct impact on queen performance, reproduction, or quality metrics. We suggest that previously reported associations between high levels of pesticide residues in wax and queen failure are most likely driven by indirect effects of worker exposure (either through wax or other hive products) on queen care or queen perception.

Download Full-text

Quantifying the effects of pollen nutrition on honey bee queen egg laying with a new laboratory system

PLoS ONE ◽

10.1371/journal.pone.0203444 ◽

2018 ◽

Vol 13 (9) ◽

pp. e0203444 ◽

Cited By ~ 9

Author(s):

Julia D. Fine ◽

Hagai Y. Shpigler ◽

Allyson M. Ray ◽

Nathanael J. Beach ◽

Alison L. Sankey ◽

...

Keyword(s):

Honey Bee ◽

Egg Laying ◽

Laboratory System ◽

Honey Bee Queen ◽

Pollen Nutrition

Download Full-text

Pesticide Exposure During Development Does Not Affect the Larval Pheromones, Feeding Rates, or Morphology of Adult Honey Bee (Apis mellifera) Queens

Frontiers in Ecology and Evolution ◽

10.3389/fevo.2021.681506 ◽

2021 ◽

Vol 9 ◽

Author(s):

Elizabeth M. Walsh ◽

Omar Khan ◽

John Grunseich ◽

Anjel M. Helms ◽

Nancy H. Ing ◽

...

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Pesticide Exposure ◽

Head Width ◽

Morphological Markers ◽

Feeding Rates ◽

Critical Signal ◽

Queen Pheromones ◽

Honey Bee Queen ◽

Queen Larvae

Recent work demonstrated that honey bee (Apis mellifera L.) queens reared in pesticide-laden beeswax exhibit significant changes in the composition of the chemicals produced by their mandibular glands including those that comprise queen mandibular pheromone, which is a critical signal used in mating as well as queen tending behavior. For the present study, we hypothesized that pesticide exposure during development would alter other queen-produced chemicals, including brood pheromone in immature queens, thus resulting in differential feeding of queen larvae by nurse workers, ultimately impacting adult queen morphology. We tested these hypotheses by rearing queens in beeswax containing field-relevant concentrations of (1) a combination of tau-fluvalinate and coumaphos, (2) amitraz, or (3) a combination of chlorothalonil and chlorpyrifos. These pesticides are ubiquitous in most commercial beekeeping operations in North America. We observed nurse feeding rates of queen larvae grafted into pesticide-laden beeswax, analyzed the chemical composition of larval queen pheromones and measured morphological markers in adult queens. Neither the nurse feeding rates, nor the chemical profiles of immature queen pheromones, differed significantly between queens reared in pesticide-laden wax compared to queens reared in pesticide-free wax. Moreover, pesticide exposure during development did not cause virgin or mated adult queens to exhibit differences in morphological markers (i.e., body weight, head width, or thorax width). These results were unexpected given our previous research and indicate that future work is needed to fully understand how pesticide exposure during development affects honey bee queen physiology, as well as how various adult queen quality metrics relate to each other.

Download Full-text

Sublethal concentrations of clothianidin affect honey bee colony growth and hive CO2 concentration

Scientific Reports ◽

10.1038/s41598-021-83958-8 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

William G. Meikle ◽

John J. Adamczyk ◽

Milagra Weiss ◽

Janie Ross ◽

Chris Werle ◽

...

Keyword(s):

Honey Bee ◽

Pesticide Exposure ◽

Co2 Concentration ◽

Colony Growth ◽

Control Group ◽

Brood Production ◽

Weight Losses ◽

Bee Colony ◽

The Impact ◽

Bee Colonies

AbstractThe effects of agricultural pesticide exposure upon honey bee colonies is of increasing interest to beekeepers and researchers, and the impact of neonicotinoid pesticides in particular has come under intense scrutiny. To explore potential colony-level effects of a neonicotinoid pesticide at field-relevant concentrations, honey bee colonies were fed 5- and 20-ppb concentrations of clothianidin in sugar syrup while control colonies were fed unadulterated syrup. Two experiments were conducted in successive years at the same site in southern Arizona, and one in the high rainfall environment of Mississippi. Across all three experiments, adult bee masses were about 21% lower among colonies fed 20-ppb clothianidin than the untreated control group, but no effects of treatment on brood production were observed. Average daily hive weight losses per day in the 5-ppb clothianidin colonies were about 39% lower post-treatment than in the 20-ppb clothianidin colonies, indicating lower consumption and/or better foraging, but the dry weights of newly-emerged adult bees were on average 6–7% lower in the 5-ppb group compared to the other groups, suggesting a nutritional problem in the 5-ppb group. Internal hive CO2 concentration was higher on average in colonies fed 20-ppb clothianidin, which could have resulted from greater CO2 production and/or reduced ventilating activity. Hive temperature average and daily variability were not affected by clothianidin exposure but did differ significantly among trials. Clothianidin was found to be, like imidacloprid, highly stable in honey in the hive environment over several months.

Download Full-text

Production and transmission of honey bee queen (Apis mellifera L.) mandibular gland pheromone

Behavioral Ecology and Sociobiology ◽

10.1007/bf00165956 ◽

1991 ◽

Vol 29 (5) ◽

pp. 321-332 ◽

Cited By ~ 84

Author(s):

Ken Naumann ◽

Mark L. Winston ◽

Keith N. Slessor ◽

Glenn D. Prestwich ◽

Francis X. Webster

Keyword(s):

Apis Mellifera ◽

Honey Bee ◽

Mandibular Gland ◽

Honey Bee Queen

Download Full-text

Queen substances from the abdomen of the honey bee queen

Journal of Comparative Physiology A ◽

10.1007/bf00297717 ◽

1970 ◽

Vol 70 (2) ◽

pp. 210-221 ◽

Cited By ~ 42

Author(s):

H. H. W. Velthuis

Keyword(s):

Honey Bee ◽

Honey Bee Queen

Download Full-text

The transcriptomic signature of low aggression honey bees resembles a response to infection

10.21203/rs.2.13415/v4 ◽

2020 ◽

Author(s):

Clare C Rittschof ◽

Benjamin E.R. Rubin ◽

Joseph H. Palmer

Keyword(s):

Health Outcomes ◽

Honey Bee ◽

Fat Body ◽

Physiological State ◽

Acute Infection ◽

Differentially Expressed ◽

Molecular Response ◽

Transcriptomic Signature ◽

Behavioral Maturation ◽

The Brain

Abstract Background: Behavior reflects an organism's health status. Many organisms display a generalized suite of behaviors that indicate infection or predict infection susceptibility. We apply this concept to honey bee aggression, a behavior that has been associated with positive health outcomes in previous studies. We sequenced the transcriptomes of the brain, fat body, and midgut of adult sibling worker bees who developed as pre-adults in relatively high versus low aggression colonies. Previous studies showed that this pre-adult experience impacts both aggressive behavior and resilience to pesticides. We performed enrichment analyses on differentially expressed genes to determine whether variation in aggression resembles the molecular response to infection. We further assessed whether the transcriptomic signature of aggression in the brain is similar to the neuromolecular response to acute predator threat, exposure to a high-aggression environment as an adult, or adult behavioral maturation. Results: Across all three tissues assessed, genes that are differentially expressed as a function of aggression significantly overlap with genes whose expression is modulated by a variety of pathogens and parasitic feeding. In the fat body, and to some degree the midgut, our data specifically support the hypothesis that low aggression resembles a diseased or parasitized state. However, we find little evidence of active infection in individuals from the low aggression group. We also find little evidence that the brain molecular signature of aggression is enriched for genes modulated by social cues that induce aggression in adults. However, we do find evidence that genes associated with adult behavioral maturation are enriched in our brain samples. Conclusions: Results support the hypothesis that low aggression resembles a molecular state of infection. This pattern is most robust in the peripheral fat body, an immune responsive tissue in the honey bee. We find no evidence of acute infection in bees from the low aggression group, suggesting the physiological state characterizing low aggression may instead predispose bees to negative health outcomes when they are exposed to additional stressors. The similarity of molecular signatures associated with the seemingly disparate traits of aggression and disease suggests that these characteristics may, in fact, be intimately tied.

Download Full-text