The fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) is a highly damaging invasive omnivorous pest that has developed varying degrees of resistance to commonly used insecticides. To investigate the molecular mechanisms of tolerance to tetraniliprole, spinetoram, and emamectin benzoate, the enzyme activity, synergistic effect, and RNA interference were implemented in S. frugiperda. The functions of cytochrome P450 monooxygenase (P450) in the tolerance to tetraniliprole, spinetoram, and emamectin benzoate in S. frugiperda was determined by analysing changes in detoxification metabolic enzyme activity and the effects of enzyme inhibitors on susceptibility to the three insecticides. 102 P450 genes were screened via transcriptome and genome, of which 67 P450 genes were differentially expressed in response to tetraniliprole, spinetoram, and emamectin benzoate and validated by quantitative real-time PCR. The expression patterns of CYP9A75, CYP340AA4, CYP340AX8v2, CYP340L16, CYP341B15v2, and CYP341B17v2 were analysed in different tissues and at different developmental stages in S. frugiperda. Silencing CYP340L16 significantly increased the susceptibility of S. frugiperda to tetraniliprole, spinetoram, and emamectin benzoate. Furthermore, knockdown of CYP340AX8v2, CYP9A75, and CYP341B17v2 significantly increased the sensitivity of S. frugiperda to tetraniliprole. Knockdown of CYP340AX8v2 and CYP340AA4 significantly increased mortality of S. frugiperda to spinetoram. Knockdown of CYP9A75 and CYP341B15v2 significantly increased the susceptibility of S. frugiperda to emamectin benzoate. These results may help to elucidate the mechanisms of tolerance to tetraniliprole, spinetoram and emamectin benzoate in S. frugiperda.

秋粘虫 (FAW)草地贪夜蛾(JE Smith) 是一种极具破坏性的入侵性杂食性害虫，对常用杀虫剂已产生不同程度的抗性。为了研究草地贪夜蛾对四苯甲酰胺、乙基多杀菌素和甲维盐的耐受性的分子机制，对草地贪夜蛾进行了酶活性、协同效应和RNA干扰。通过分析草地贪夜蛾解毒代谢酶活性的变化以及酶抑制剂对3种杀虫剂敏感性的影响，确定细胞色素P450单加氧酶（P450）在对草地贪夜蛾、乙基多杀菌素和甲维盐耐受中的作用。通过转录组和基因组筛选出 102 个 P450 基因，其中 67 个 P450 基因在丁苯甲酰胺、乙基多杀菌素和甲维盐中差异表达，并通过定量实时 PCR 进行验证。分析了草地贪夜蛾不同组织和不同发育阶段CYP9A75、CYP340AA4、CYP340AX8v2、CYP340L16、CYP341B15v2和CYP341B17v2的表达模式。沉默CYP340L16显着增加了草地贪夜蛾对四苯甲酰胺、乙基多杀菌素和甲维盐的敏感性。此外，CYP340AX8v2、CYP9A75和CYP341B17v2的敲低显着增加了草地贪夜蛾对四苯甲酰胺的敏感性。 CYP340AX8v2和CYP340AA4的敲低显着增加了草地贪夜蛾对乙基多杀菌素的死亡率。CYP9A75和CYP341B15v2的敲低显着增加了草地贪夜蛾对甲维盐苯甲酸盐的敏感性。这些结果可能有助于阐明草地贪夜蛾对四苯甲酰胺、乙基多杀菌素和甲维盐的耐受机制。