Sublethal effects of nitenpyram on the biological traits and metabolic enzymes of the white-backed planthopper, Sogatella furcifera (Hemiptera: Delphacidae)

Abstract

Neonicotinoid insecticide nitenpyram is widely used in controlling rice hoppers including Sogatella furcifera (Horváth). At present, the effects of nitenpyram on the biological traits and metabolic enzymes of S. furcifera remain unclear. In this study, we applied an age-stage, two-sex life table to evaluate the sublethal effects of nitenpyram on S. furcifera under one- or multi-generation exposure. Fecundity of F0 individuals was significantly decreased in the LC25 treatment group compared to the control. Additionally, in contrast to control, the preadult period, male adult longevity, female adult longevity, longevity, total preoviposition period (TPOP), oviposition days and fecundity were significantly decreased in the F1 and F6 generations, while the development time of the 1st, 3rd and 5th -instar in the F6 generation were significantly shorter than the control and (or) the F1 generation. Moreover, except for the mean generation time (T) that was significantly decreased in the F1 and F6 generations, other population parameters such as the intrinsic rate of increase (ri), finite rate of increase (λ) and net reproductive rate (R0) were not influenced by nitenpyram exposure. The P450 and EST were both significantly increased in the F0 and F6 individuals after nitenpyram (LC25) treatment, and the P450 showed a higher activity in the F6 generation than F0. The mRNA levels of four P450 genes (CYP4CE3, CYP417A4, CYP439A3 and CYP6FJ3) were induced by nitenpyram (LC25) treatment in both the F0 and F6 generation, and these four P450 genes were also significantly upregulated in the F6 generation compared with F0. Our findings are useful for developing rational application strategies for using pesticides and understanding the metabolic resistance of nitenpyram in S. furcifera.