Department of Economic Entomology and Pesticides, Faculty of Agriculture, Cairo University, Giza, 12613, Egypt.
Department of Biochemistry, Faculty of Agriculture, Cairo University, Giza, 12613, Egypt.
Sci Rep. 2022 Apr 28;12(1):6974. doi: 10.1038/s41598-022-10812-w.
Methoxyfenozide (M) is one of the selective insecticides used in integrated pest management (IPM) programs for lepidopteran pests. However, recent studies reported a development of M-resistance, which prompted us to look for alternatives. Here, we investigate the potency of a mixture of M with spinetoram (Sp) on M-resistant insects. In the laboratory, a selection pressure with M has carried out on Spodoptera littoralis (Lepidoptera: Noctuidae) strains. A dipping technique was used to evaluate the toxicity of a sublethal concentration of M and Sp. on S. littoralis larvae, and the same concentrations were used to assess the toxic impact of their combination on susceptible (SUS) and M-selected (MS) strains. The toxicity of M/Sp mixtures was computed using a combination index equation, and a potentiation effect was observed in the two tested strains. Synergism tests revealed that piperonyl butoxide had considerable synergistic effects on M toxicity in the MS strain. The results revealed that the M/Sp mixture's negative effect on both monooxygenases and esterases is most likely the cause of its potentiation effect on the SUS and MS strains. It was concluded that M/Sp mixtures are effective against M-resistant S. littoralis strains, so these can be used in IPM programs.
甲氧虫酰肼（M）是综合虫害管理（IPM）计划中用于鳞翅目害虫的选择性杀虫剂之一。然而，最近的研究报告称出现了对 M 的抗药性发展，这促使我们寻找替代品。在这里，我们研究了 M 与乙基多杀菌素（Sp）混合物对 M 抗性昆虫的效力。在实验室中，对斜纹夜蛾（鳞翅目：夜蛾科）品系进行了 M 选择压力。采用浸渍技术评估亚致死浓度的 M 和 Sp 对 S. littoralis 幼虫的毒性，并用相同浓度评估其组合对敏感（SUS）和 M 选择（MS）品系的毒性影响。使用组合指数方程计算 M/Sp 混合物的毒性，在两种测试品系中观察到增效作用。增效作用测试表明，增效醚对 MS 品系中 M 的毒性具有相当大的增效作用。结果表明，M/Sp 混合物对单加氧酶和酯酶的负面影响很可能是其对 SUS 和 MS 品系增效作用的原因。结论是 M/Sp 混合物对 M 抗性斜纹夜蛾品系有效，因此可用于 IPM 计划。
