The whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) cryptic species has become an important pest of cotton and vegetable crops in Egypt. In this study, resistance to three organophosphate insecticides (OPs), chlorpyrifos-methyl, profenofos and pirimiphos-methyl, and detoxification enzymatic activities of acetylcholinesterase, carboxylesterase, and monooxygenase were evaluated to establish baseline resistance levels for B. tabaci infesting cotton in seven Egyptian governorates, compared to a susceptible laboratory reference B. tabaci colony. Resistance to OPs ranged from low-to-moderate or low-to-high, while detoxification enzymatic activities were predominantly governorate-dependent. Phylogenetic analysis of a fragment of the mitochondria cytochrome oxidase I gene (756 bp) identified field-collected B. tabaci as the B mitotype. The results provide baseline OP resistance levels for B. tabaci that will aid in interpreting future monitoring outcomes and enable detection of insecticide resistance fluxes.

中文翻译：

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埃及粉虱 Bemisia tabaci (Hemiptera: Aleyrodidae) 自然种群对有机磷杀虫剂的代谢抗性及细胞分裂型的分子鉴定

粉虱 Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) 隐种已成为埃及棉花和蔬菜作物的重要害虫。在这项研究中，评估了对三种有机磷杀虫剂 (OP)、甲基毒死蜱、丙溴磷和甲基嘧啶磷的抗性，以及乙酰胆碱酯酶、羧酸酯酶和单加氧酶的解毒酶活性，以建立七个埃及烟粉虱侵染棉花的基线抗性水平省，与易感的实验室参考烟粉虱菌落相比。对 OPs 的抗性范围从低到中等或从低到高，而解毒酶活性主要依赖于省份。线粒体细胞色素氧化酶 I 基因 (756 bp) 片段的系统发育分析将现场收集的烟粉虱确定为 B 有丝分裂型。