Indirect exposure to insect growth disruptors affects honey bee (Apis mellifera) reproductive behaviors and ovarian protein expression

PLoS One. 2023 Oct 2;18(10):e0292176. doi: 10.1371/journal.pone.0292176. eCollection 2023.

Abstract

Pesticide exposure and queen loss are considered to be major causes of honey bee colony mortality, yet little is known regarding the effects of regularly encountered agrochemicals on honey bee reproduction. Here, we present the results of a two-generational study using specialized cages to expose queens to commonly used insect growth disrupting pesticides (IGDs) via their retinue of worker bees. Under IGD exposure, we tracked queen performance and worker responses to queens, then the performance of the exposed queens' offspring was assessed to identify patterns that may contribute to the long-term health and stability of a social insect colony. The positive control, novaluron, resulted in deformed larvae hatching from eggs laid by exposed queens, and methoxyfenozide, diflubenzuron, and novaluron caused a slight decrease in daily egg laying rates, but this was not reflected in the total egg production over the course of the experiment. Curiously, eggs laid by queens exposed to pyriproxyfen exhibited increased hatching rates, and those larvae developed into worker progeny with increased responsiveness to their queens. Additionally, pyriproxyfen and novaluron exposure affected the queen ovarian protein expression, with the overwhelming majority of differentially expressed proteins coming from the pyriproxyfen exposure. We discuss these results and the potential implications for honey bee reproduction and colony health.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bees
  • Insecta
  • Larva
  • Pesticides* / toxicity
  • Phenylurea Compounds*
  • Reproduction

Substances

  • novaluron
  • Phenylurea Compounds
  • Pesticides

Grants and funding

“Leonard J. Foster was supported by an NSERC Discovery Grant and the proteomics work was supported by Genome Canada and Genome BC (264PRO). Alison McAfee was supported by a Natural Sciences and Engineering Research Council postdoctoral fellowship and a L’Oreal-UNESCO postdoctoral fellowship. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.”