Sublethal effects of the novel cis-nitromethylene neonicotinoid cycloxaprid on the cotton aphid Aphis gossypii Glover (H em iptera: Aphididae)

Cycloxaprid is a novel cis-configuration neonicotinoid insecticide that is effective against a wide range of insect pests, including those that are resistant to conventional neonicotinoids. In this study, life table parameters were applied to estimate the cycloxaprid-induced sublethal effects on Aphis gossypii. The results indicated that the LC20 (0.81 mg a.i. L-1) of cycloxaprid significantly decreased the preoviposition period in first-progeny adults. Additionally, the life expectancy of F1 generation adults was reduced. However, no significant differences were observed for the intrinsic rate of increase (r(i)), finite rate of increase (lambda), net reproductive rate (R-0), or mean generation time (T) of F1 individuals. Therefore, resurgence in the A. gossypii population induced by a low concentration of cycloxaprid might not occur. Additionally, the response of the detoxification enzymes showed that cycloxaprid at the LC20 inhibited cytochrome P450 monooxygenase (P450) and glutathione S-transferase (GST) activities at 6 h after exposure. Such inhibition of P450 and GST activities could lead to a decrease in the metabolism of cycloxaprid, which would increase the efficacy of cycloxaprid. Therefore, our results contribute to the assessment of the overall effects of cycloxaprid on A. gossypii.