Imidacloprid resistance of melon thrips, Thrips palmi, is conferred by CYP450-mediated detoxification

Abstract

The nicotinic acetylcholine receptor β1 subunit gene of the most imidacloprid-susceptible (OK) strain and the most imidacloprid-resistant (TS7) strain of Thrips palmi encoded a susceptible amino acid, Arg, at amino acid position 81. The OK and TS7 strains showed LC₅₀ values of 9.4 mg/L and 115.0 mg/L, respectively. The synergist, piperonyl butoxide, decreased the resistance ratio to one-third in the TS7 strain. These results suggest that the imidacloprid resistance in T. palmi is conferred mainly by cytochrome P450-mediated detoxification.