Fecha de publicación: -- Fuente: PubMed "honey" J Environ Manage. 2026 Nov 4;420:131264. doi: 10.1016/j.jenvman.2026.131264. Online ahead of print.ABSTRACTUbiquitous pesticide pollution is a major driver of global wild insect declines and annual managed bee losses. Sensitivity to these chemicals may vary across species, sexes, and ecological contexts. Improving our understanding of the biological and behavioural factors shaping these variations is essential to ensure accuracy in toxicity testing and environmental risk assessment (ERA) schemes. Here, we show clear inter- and intraspecific differences in sensitivity to oral chronic neonicotinoid exposure. Using modified OECD 245 guidelines, we orally exposed female and male honey bees, Apis mellifera, bumble bees, Bombus terrestris, and solitary bees, Osmia bicornis chronically to different thiamethoxam concentrations and monitored mortality and feeding behaviour. When feeding at field-relevant concentrations (< 40 ng g-1), individuals remained unaffected across species. However, species-specific sensitivity to thiamethoxam differed: A. mellifera was the most vulnerable, followed by O. bicornis and B. terrestris. Within species, males were generally more sensitive than females (workers), and female honey bees engaged in tending males exhibited greater mortality than idle counterparts-demonstrating that behaviours can modulate sensitivity to chemicals. While reliance on female honey bees in current ERA schemes may align with the precautionary principle for interspecific variation, our findings show that interspecific differences - particularly between sexes and behavioural states - can substantially influence sensitivity. We therefore advocate for the integration of both sexes and behaviourally relevant conditions into future Tier-1 laboratory toxicity testing to improve the accuracy and ecological relevance of lower tier pollinator risk assessments. Improving our knowledge of how pesticide sensitivity varies in relation to sex differences or behaviours is essential to increase the realism of lower tier ERA estimates to ensure more informed evidence-based policy required to protect non-target species.PMID:42981867 | DOI:10.1016/j.jenvman.2026.131264