Sublethal exposure to the insecticide chlorantraniliprole does not alter antipredator behaviour in wild field crickets

Abstract

Pesticide exposure has been proposed as a major driver of global insect declines. Sublethal effects occur when non-fatal pesticide exposure disrupts behaviour or physiology in ways that may reduce survival or reproductive success. However, most evidence for sublethal effects comes from laboratory studies under controlled conditions. We tested whether exposure to a sublethal dose of chlorantraniliprole, a widely used diamide insecticide known for its long environmental persistence, affects antipredator escape behaviours in wild field crickets (Gryllus campestris). Adult crickets were treated with either pesticide or a sham control. They then underwent behavioural tests in the wild. Following a simulated predator attack, we measured two key behaviours: escape speed and subsequent latency to re-emerge from their burrow. We found no consistent effects of pesticide exposure on either behaviour. Re-emergence latency increased over successive days across both groups, while escape speed did not change. Re-emergence latency showed greater individual variability than escape speed. This likely reflects its role as a risk-assessment behaviour, which is more context-dependent than escape speed. Our findings challenge the assumption, largely derived from laboratory assays, that sublethal pesticide exposure universally impairs insect behaviour. Overall, our results underscore the need to integrate environmental context when evaluating pesticide impacts on insect behaviour.