An important role of a pyrethroid-sensing residue F1519 in the action of the N-alkylamide insecticide BTG 502 on the cockroach sodium channel

► BTG 502 reduced the amplitude of sodium currents. ► Two pyrethroid-resistant mutations, super-kdr mutations, did not affect the action of BTG 502. ► A pyrethroid-resistant mutation, F1519I, abolished the action of BTG 502 on sodium channels.