关键词: 草地贪夜蛾, 抗药性, 氨基甲酸酯, 拟除虫菊酯, 双酰胺, 抗性基因, 突变频率

Abstract: 【Background】The fall armyworm (Spodoptera frugiperda) is an most damaging agricultural pest in the tropical and subtropical areas of America, it has rapidly expanded to more than 100 countries around the world since 2016, and has now invaded 27 provinces in China, posing a great threat to food security. Resistance may become an increasingly serious problem in many regions with the heavy reliance on insecticides for several years and lead to low control efficiency. FAW had spread to the north of the Great Wall rapidly. However, there are few studies on insecticide resistance and annual variation in China, especially the Protection zone of the Great Wall.【Objective】The objective of this study is to clarify susceptibility and differences of S. frugiperda populations to insecticides in the Great Wall protection zone and other area of China, and provide evidence for rational use of insecticide.【Method】Samples of FAW were collected from maize fields in 13 provinces (Autonomous Region, Municipality)  in China，and the genomic DNA was extracted. The mutations of resistance targets to carbamate, pyretoid and bisamide insecticides in 362 individuals collected from 47 cities (districts) of 13 provinces (Autonomous Region, Municipality) in 2020 and 2021 were analyzed with sequencing of the PCR products individually. 【Result】There were 6 genotypes of mutations with frequency of 40.6% in ace-1 to carbamate insecticides in all the samples. The frequency of A201S heterozygous and homozygous mutations were 8.4% and 14.9%, respectively, and the frequency of F290V heterozygous mutations was 25.7%, which was higher in the key prevention region than that in the migratory transition region and annual breeding region, while the frequency of A201S mutation was lower than that in both regions. The average frequency of ace-1 mutation was higher in the Great Wall protection zone, and that in Huang-Huai-Hai interception zone, Yangtze River Basin and southwest and South China protection zone were similar and low. There was no significant difference in the frequency of ace-1 mutation between the populations in 2021 and 2020. No mutations were detected in pyrethroid vgsc and bisamide ryr.【Conclusion】A201S and F290V mutations with high frequency in ace-1 is one of the mechanisms conferring carbamate resistance in many populations in China. The use of Carbamates should be restricted in the control of S. frugiperda. No mutations had been detected in the vgsc and ryr, suggesting susceptibility to pyrethroids and diamides for rational rotation, however, the low frequency of mutation in S. frugiperda and common mutation in Spodoptera exigua (relatives of S. frugiperda) to pyrethroids and diamides have been detected, so we should evaluate the resistance of median lethal concentration and target mutation with high selection stress in the lab and field populations fed by different host and establish rapid diagnostics methods of insecticide resistance for the sustainable control of S. frugiperda.

Key words: Spodoptera frugiperda, insecticide resistance, carbamate, pyrethroid, diamide, resistance gene, mutation frequency