# Insecticide exposure alters feeding and impairs ovary development in a solitary bee

## TL;DR

Exposure to insecticides like imidacloprid reduces feeding and impairs reproduction in solitary bees, even at low levels.

## Contribution

The study identifies a novel mechanism linking insecticide exposure to reduced reproduction through feeding and ovary development.

## Key findings

- Adult exposure to imidacloprid reduces pollen and nectar feeding in solitary bees.
- Exposure as adults, but not larvae, impairs ovary maturation in Osmia lignaria.
- Negative reproductive impacts may stem from reduced ovary development due to feeding suppression.

## Abstract

Insecticide exposure is a growing concern due to its implication in population declines and disruption of key ecosystem services such as pollination. Bees and other beneficial insects can be exposed to insecticides multiple times throughout their lives and across generations, with impacts on behavior and reproduction. To investigate mechanisms underlying reduced reproduction in bees exposed to insecticide over time, I quantified the direct and carryover effects of insecticide exposure on the feeding and ovary development of the solitary bee, Osmia lignaria. Bees were exposed to the insecticide, imidacloprid, as larvae and/or as adults in a fully crossed design over two years. Insecticide exposure to bees as adults, but not as larvae, reduced pollen and nectar feeding and impaired ovary maturation. These findings reveal mechanisms underlying insecticide effects on bees, indicating that negative impacts on reproduction may be attributed to reduced ovary development driven by the anti-feeding effects of imidacloprid, even at low levels of exposure.

The online version contains supplementary material available at 10.1007/s10646-025-03019-y.