草地贪夜蛾对四唑虫酰胺的抗性风险评估及代谢抗性机制分析OA

[Aim]This study aims to assess the risk of Spodoptera frugiperda developing resistance to tetraniliprole and to elucidate the impacts of sublethal concentrations of tetraniliprole on the development,reproduction and detoxification enzyme activities of S.frugiperda,so as to lay a theoretical foundation for the rational application of tetraniliprole in pest management strategies.[Methods]The resistance selection of S.frugiperda to tetraniliprole was carried out using the diet incorporation method.The realized heritability(h2)of resistance was calculated via the threshold trait analysis method,and the numbers of generations required for S.frugiperda to develop 10-fold resistance to tetraniliprole under different selection pressures were predicted based on h2.The age-stage,two-sex life table was employed to analyze the effects of sublethal concentrations(LC10 and LC30)of tetraniliprole on the developmental and reproductive parameters of S.frugiperda,including larval duration,prepupal duration,pupal duration,female and male adult longevity,and number of eggs laid per female.Moreover,the synergistic effects of three synergists including triphenyl phosphate(TPP),diethyl maleate(DEM)and piperonyl butoxide(PBO)on tetraniliprole were determined,and the changes in the activities of mixed-functional oxidase(MFO),glutathione S-transferase(GST)and carboxylesterase(CarE)in the 3rd instar larvae of S.frugiperda after treatment with sublethal concentration(LC30)of tetraniliprole were measured.[Results]After 14 generations of laboratory resistance selection with tetraniliprole,the resistance ratio of S.frugiperda was 2.4,with the h2 of 0.077.The highest resistance(5.3-fold)during the entire screening process was observed in the 11th generation,with the h2 of 0.206.Based on this h2,it was predicted that under the pesticide selection pressure at 50％mortality,it only took 15.9 generations for S.frugiperda to develop 10-fold resistance to tetraniliprole.After treatment with sublethal concentrations(LC10 and LC30)of tetraniliprole,the larval duration,prepupal duration,pupal duration,female adult longevity,male adult longevity,and total pre-oviposition period of S.frugiperda were all significantly prolonged,as compared with those in the untreated control.The number of eggs laid per female was significantly reduced,the intrinsic rate of increase(rm),net reproductive rate(R0)and finite rate of increase(λ)in the treatments with LC10 and LC30 of tetraniliprole were all significantly decreased,as compared with those in the untreated control.The gross reproductive rate(GRR)of S.frugiperda showed a trend of decreasing after treatment with low sublethal concentration(LC10)of tetraniliprole and increasing after treatment with high sublethal concentration(LC30)of tetraniliprole.The synergistic ratios of the synergists TPP,DEM and PBO on the toxicity of tetraniliprole to the 3rd instar larvae of S.frugiperda were 1.3,1.0 and 1.6,respectively.At 72 h after treatment with LC30 of tetraniliprole,the MFO activity in the 3rd instar larvae of S.frugiperda was significantly higher than that of the control.[Conclusion]There is a certain resistance risk of S.frugiperda to tetraniliprole.Treatment with sublethal concentrations of tetraniliprole can prolong the developmental duration of S.frugiperda and reduce its population fecundity.However,there is a phenomenon that the number of eggs laid by some individuals may increase due to the stimulation of the pesticide,resulting in an increase in GRR.S.frugiperda mainly metabolizes and detoxifies tetraniliprole by enhancing the MFO activity.