The development, reproduction and P450 enzyme of the white-backed planthopper, Sogatella furcifera (Hemiptera: Delphacidae) under the sublethal concentrations of clothianidin

Abstract

Clothianidin is a second-generation neonicotinoid insecticide that can effectively prevent piercing-sucking pests, such as white-backed planthopper (WBPH), Sogatella furcifera (Horváth). In this study, the sublethal effects of clothianidin on the biological traits of S. furcifera were evaluated via the age-stage, two-sex life table procedure. Our results exhibited that the female adult longevity, fecundity and hatchability of F0 generation were significantly decreased after LC10 and (or) LC30 of clothianidin exposure compared to the control. Transgenerational effects showed that the pre-adult period, female adult longevity, total longevity, oviposition days (Od), fecundity and mean generation time (T) of F1 generation were significantly decreased in the LC10 and LC30 groups compared to the control. Moreover, the development times of the third- and fifth-instar nymphs, total preoviposition period (TPOP) and doubling time (DT) were significantly shorter in the LC10 group than in the control and LC30 groups. Furthermore, the intrinsic rate of increase (ri) and finite rate of increase (λ) values of the LC10 group were significantly higher than those of the control group. However, there was no significant difference in the male adult longevity, adult preoviposition period (APOP) and net reproductive rate (R0) between the treated groups and the control. Enzyme activity and gene expression results showed that the P450 enzyme activity and mRNA levels of many P450 genes were significantly increased by clothianidin treatment. In addition, the knockdown of CYP4CE3 and CYP6FJ3, which showed the highest inducing levels, by RNA interference (RNAi) dramatically increased the toxicity of clothianidin against S. furcifera. These results indicated that sublethal concentrations of clothianidin showed a stimulatory effect on the development, but it could adversely affect the survival and reproduction of S. furcifera. Additionally, CYP4CE3 and CYP6FJ3 might play an important role in the detoxification and evolution of clothianidin resistance in S. furcifera.