Pesticides including neonicotinoids and fungicides cause sublethal welfare harms in bees, impairing navigation, reproduction, and immunity at population scale.
Bees experiencing sublethal pesticide effects cannot accurately navigate back to their hives, leading to death from exposure or starvation. Impaired reproduction reduces colony size and resilience. Fungicide-gut microbiome disruption increases susceptibility to Nosema parasites. Colony collapse disorder, while multi-factorial, is associated with pesticide exposure as a key stressor. The welfare impact of pesticide-impaired colonies involves millions of individual bees dying of starvation, cold, or infection.