Cross-resistance patterns and fitness in fufenozide-resistant diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

BACKGROUND: Fufenozide is a novel non‐steroidal ecdysone agonist with good efficacy against diamondback moth (DBM), Plutella xylostella (Lepidoptera: Plutellidae). At present, it is widely applied for the control of a range of lepidopterous pests in China. This study compared the activities of fufenozide and 12 other insecticides against unselected and fufenozide‐selected strains of DBM to examine potential patterns of cross‐resistance. The relative fitness of the fufenozide‐selected strain was assessed to provide information pertinent to insecticide resistance management. RESULTS: Compared with the susceptible strain (JSS), the fufenozide‐resistant strain (JSR) showed high cross‐resistance to dibenzoylhydrazines and benzoylphenylureas, low cross‐resistance to abamectin and no cross‐resistance to organophosphates, carbamates and pyrethroids. JSR had a lower reproductive ability and a relative fitness of 0.5 compared with JSS. CONCLUSION: P. xylostella has the potential to develop resistance to fufenozide, albeit at the expense of fitness. Cross‐resistance between the same and other classes of insecticides is of concern, and should be a key consideration when implementing fufenozide‐based control strategies for this species. Copyright © 2011 Society of Chemical Industry