The behavioral toxicity of insect growth disruptors on Apis mellifera queen care

Authors: Litsey, Eliza; CHUNG, SIWON - University Of Texas Southwestern Medical Center; Fine, Julia

Submitted to: Frontiers in Ecology and Evolution
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/31/2021
Publication Date: 10/7/2021
Citation: Litsey, E.M., Chung, S., Fine, J.D. 2021. The behavioral toxicity of insect growth disruptors on Apis mellifera queen care. Frontiers in Ecology and Evolution. 9. Article 729208. https://doi.org/10.3389/fevo.2021.729208.
DOI: https://doi.org/10.3389/fevo.2021.729208

Interpretive Summary: As social insects, honey bees rely on the coordinated performance of various behaviors to ensure that the needs of the colony are met. One of the most critical of these behaviors is the feeding and care of egg laying honey bee queens by worker bee attendants. These important queen care behaviors are elicited from workers by the queen’s pheromone blend. Worker bee responsiveness to this blend can vary depending on their physiological status, but little is known regarding the impacts of exposure to agrochemicals during development on this behavior. This work investigates how exposing workers as larvae to chronic sublethal doses of insect growth disruptors affects their development time, weight, longevity, and response to queen pheromone as adult worker honey bees. Exposure to the juvenile hormone analogue pyriproxyfen consistently shortened the duration of pupation, suggesting that exposure to a Juvenile Hormone analogue during development may encourage the development of intercaste characteristics in honey bees. Other treatment dependent effects varied among replicates, but when developmental exposure to pyriproxyfen did not result in reduced rates of adult survival, pyriproxyfen treated bees were found to be less responsive to queen pheromone relative to other treatment groups. Here, we describe these results and discuss their possible physiological underpinnings as well as their potential impacts on honey bee reproduction and colony performance.

Technical Abstract: As social insects, honey bees (Apis mellifera) rely on the coordinated performance of various behaviors to ensure that the needs of the colony are met. One of the most critical of these behaviors is the feeding and care of egg laying honey bee queens by sterile female worker attendants. These behaviors are crucial to honey bee reproduction and are known to be elicited by the queen’s pheromone blend. The degree to which workers respond to this blend can vary depending on their physiological status, but little is known regarding the impacts of developmental exposure to agrochemicals on this behavior. This work investigates how exposing workers during larval development to chronic sublethal doses of insect growth disruptors affects their development time, weight, longevity, and queen pheromone responsiveness as adult worker honey bees. Exposure to the juvenile hormone analogue pyriproxyfen consistently shortened the duration of pupation, suggesting that exposure to a Juvenile Hormone analogue during development may encourage the development of intercaste characteristics in honey bees. Other treatment dependent effects varied among replicates, but when developmental exposure to pyriproxyfen did not result in reduced rates of adult survival, pyriproxyfen treated bees were found to be less responsive to queen pheromone relative to other treatment groups. Here, we describe these results and discuss their possible physiological underpinnings as well as their potential impacts on honey bee reproduction and colony performance.