Acute and chronic pesticide effects on honey bees, bumble bees, and solitary bees

The study investigates acute and chronic effects of agrochemicals—sulfoxaflor, azoxystrobin, glyphosate, and others—on honey bees (Apis mellifera), bumble bees (Bombus terrestris), and solitary bees (Osmia bicornis). It assesses lethal (LD50) and sublethal endpoints, including mortality, reproductive performance, foraging activity, and survival under field-realistic conditions. Findings reveal significant variability in pesticide sensitivity across bee species, subspecies, castes, and genetic lineages, with queens showing greater tolerance than workers. Non-monotonic dose-response relationships were observed for sulfoxaflor, and synergistic effects were noted under certain exposure conditions, particularly under contact exposure. Chronic exposure to sulfoxaflor reduced flight activity and foraging in honey bees and impaired fecundity in bumble bees, especially under nutritional stress. Solitary bees showed reduced long-term survival after exposure to field-realistic doses of sulfoxaflor. The research highlights the importance of considering non-lethal effects, genetic background, and environmental stressors in pesticide risk assessment, supporting the need for updated regulatory guidelines. Data were generated under the Horizon 2020 PoshBee project (grant 773921), with standardized OECD protocols and validated across multiple European institutions.