Insecticide Resistance Monitoring And The Detoxification Enzyme Activity Analyses Of Carposina Sasakii In Shaanxi Province

The peach fruit moth,Carposina sasakii Matsumura is one of the important serious fruit borers.It is distributed in the most fruit growing areas in China,causing serious economic losses every year.Chemical insecticide spraying together with fruit-bagging is the main control tactic to manage the peach fruit moth.However,the long-term use of chemical insecticides can cause insecticide resistance.In this study,we monitored the the insecticide resistance of peach fruit moth field populations from four areas of Shaanxi Province.The activity of three detoxification enzyme（P450,GST and Car E）of the moth from different regions was analyzed.The gene sequences of the three three detoxification enzyme were identified by transcriptome data.The change of detoxification enzyme acticity and gene expression of the moth was investigated after treating the larvae with three generations.The main results are as follows:1.The toxicity of lambda-cyhalothrin,chlorpyrifos,abamectin and chlorantraniliprole to the peach fruit moth was determined by fruit dipping and residual film bioassay method.It was found that the fruit dipping method was easier and reliable.The results from fruit dipping method showed that chlorpyrifos had the highest toxicity to the fruit moth(LC₅₀0.9655mg/L),and the abamectin had the lowest toxicity(LC₅₀ 5.3980mg/L).2.The resistance level of C.sasakii field populations from the apple orchard of Xingping,Baishui,Xunyi and Fengxiang was monitored by fruit dipping method.Compared to the relative susceptible strain,the field populations from the four areas are sensitive to lambda-cyhalothrin,chlorpyrifos,abamectin and chlorantraniliprole.The correlation between LC₅₀ of the insecticides was analyzed.It was found that there was a significant positive correlation between lambda-cyhalothrin and chlorantraniliprole LC₅₀.There was no significant correlation between LC₅₀of chlorpyrifos and abamectin and chlorantraniliprole,or between abamectin and chlorantraniliprole.3.The P450,GST and Car E enzyme activities of C.sasakii field populations were measured.It was found that the cytochrome P450 enzyme activities and glutathione S-transferase activities of four field populations were significantly higher than those of the relative susceptible strains.The P450 enzyme activity of peach fruit moth from Baishui was the highest,and the P450 enzyme activity of the peach fruit moth from Fengxiang area was the lowes.The carboxylesterase activity of the field populations was significantly lower than that of the relative susceptible strain.After continuous treatment the larvae with sublethal concentrations(LC₂₀,LC₃₅and LC₅₀)of lambda-cyhalothrin by three generations,the P450 enzyme activity of the moth was significantly increased.The GST activity was signiciantly increased after treatment by LC₅₀ concentration of the chemical.The Car E activity was increased in some extent,but the difference was not significant.4.After treatment with three sublethal concentrations lambda-cyhalothrin(LC₂₀,LC₃₅and LC₅₀)by three generations of continuous,the egg stage and larval stage of fruit moth were prolonged in some extent.The egg stage and larval stage of fruit moth were prolonged by 0.62 days and 1.74 days after the treating with LC₅₀ concentraion of the insecticide.After LC₃₅ and LC₅₀ concentration treatments,the egg stage and larval stage were significantly prolonged,the longevity of adults was significantly shoretened,and the egg number,the ratio of male to female,the matural larve exiting rate and cocooning rate were significantly decreased.5.By analyzing the transcriptome data,167 gene sequences of detoxification enzyme were identified,including 97 P450 gene sequences,34 GST gene sequences and 36carboxylesterase gene sequences.q RT-PCR was used to investigate the expression level of detoxifying enzyme gene after three generations of treatment with LC₅₀lambda-cyhalothrin.The results showed that CYP6AB14,CYP6B5,CYP6B46,P4506B2 and P4506B7 were significantly up-regulated.GSTomega1,GSTE14-like,GSTepsilon3 and GSTsigma1 were significantly up-regulated.In conclusion,this study monitored the resistance status of four geographical populations of peach fruit moth in Shaanxi Province in 2021,determined the activity of related detoxifying enzymes,and preliminarily analyzed the role of detoxifying enzymes in resistance.At the same time,the sublethal concentration of lambda-cyhalothrin was used to treat the peach fruit moth,and the effects of lambda-cyhalothrin on the growth and development of the peach fruit moth were analyzed.These results provide a scientific basis for the resistance management and guiding significance for the production practice.