Pyrethroid and indoxacarb are commonly used pesticides to control the fall armyworm (Spodoptera frugiperda) in the crops. There are a series of consequences caused by the use of pyrethroid and indoxacarb pesticides under emergency control, such as pest resistance development, contamination of soil, water, and farm products. This study analyzed the structure and physiological function of the sodium channel in S. frugiperda, which is an important step to elaborate the resistance mechanism of S. frugiperda to indoxacarb and pyrethroid pesticides. According to genetic analysis, the cloned cDNA sequences of sodium channel in S. frugiperda (SfNa_v) showed the shortest genetic distance with that of the sodium channel in Helicoverpa armigera. Under the induction of three pesticides, the expression of SfNa_v decreased in the first 12 h and then increased after 24 h. It was concluded that SfNa_v had a typical structure of the sodium channel of insects and its down-regulated expression can decrease the combination of S. frugiperda with pyrethroid and indoxacarb pesticides. The up-regulated expression of SfNa_v was conducive to the enhancement of the pesticide resistance.

拟除虫菊酯和茚虫威是控制农作物中秋夜蛾（Spodoptera frugiperda）的常用杀虫剂。在紧急控制下使用拟除虫菊酯和茚虫威杀虫剂会带来一系列后果，例如害虫抗药性发展，土壤，水和农产品的污染。本研究分析了沙门氏菌钠通道的结构和生理功能，这是阐明沙门氏菌对茚虫威和拟除虫菊酯类农药抗性机制的重要步骤。根据遗传分析，克隆的cDNA中钠通道序列草地贪夜蛾（SfNa _v）与棉铃虫的钠通道遗传距离最短。在3种农药的诱导下，SfNa _v的表达在前12h下降，24h后上升。结论是，SfNa _v具有昆虫钠通道的典型结构，其表达下调可减少S. frugiperda与拟除虫菊酯和茚虫威农药的组合。SfNa _v的表达上调有利于提高抗药性。