Species-specific patterns of swimming escape performance and cholinesterase activity in a guild of aquatic insects exposed to endosulfan

► Endosulfan, even at lethal levels, did not affect swimming propensity when attacked. ► Endosulfan reduced escape swimming in one out of four tested corixid species. ► Lower body ChE levels were associated with a slower escape speed in one species. ► Head AChE activity was more sensitive to endosulfan than body ChE. ► Endosulfan had strongly different effects on the closely related species.