新疆和云南番茄潜叶蛾种群对六种杀虫剂的敏感性及其与解毒酶活性的关系

【目的】番茄潜叶蛾Tuta absoluta 是新入侵我国的对番茄具有毁灭性危害的入侵害虫，目前入侵我国的番茄潜叶蛾种群对杀虫剂的抗性尚无报道。本研究旨在明确新疆和云南番茄潜叶蛾田间种群对6种常用杀虫剂的敏感性及其与解毒酶活性的关系。【方法】采用浸叶法测定6种常用杀虫剂对番茄潜叶蛾新疆和云南种群2龄幼虫的室内毒力。通过对2龄幼虫的生物测定确定3种增效剂［CYP450抑制剂胡椒基丁醚(PBO)、酯酶抑制剂磷酸三苯酯(TPP)和GST抑制剂丁烯二酸二乙酯(DEM)］对氯虫苯甲酰胺的增效作用。采用酶活性分析测定室内敏感种群和田间抗性种群(新疆种群) 2龄幼虫体内解毒酶［细胞色素P450酶(CYP450)、谷胱甘肽S-转移酶(GST)和羧酸酯酶(CarE)］活性，以确定杀虫剂抗性与解毒酶活性的关系。【结果】番茄潜叶蛾云南种群对6种杀虫剂的敏感性由高到低依次为甲维盐、溴虫腈、多杀菌素、茚虫威、氯虫苯甲酰胺和高效氯氰菊酯。新疆种群对6种杀虫剂的敏感性由高到低依次为甲维盐、溴虫腈、氯虫苯甲酰胺、多杀菌素、茚虫威和高效氯氰菊酯。与室内敏感种群相比，云南和新疆种群对氯虫苯甲酰胺的抗性水平最高，抗性倍数分别为212.7和169.3倍。生物测定结果表明，3种增效剂PBO, TPP和DEM均对氯虫苯甲酰胺无明显增效作用。酶活性测定结果表明，番茄潜叶蛾室内敏感种群和田间抗性种群之间2龄幼虫中CYP450, GST和CarE活性无显著差异。【结论】番茄潜叶蛾新疆和云南种群对测试的6种杀虫剂产生不同程度的抗性，对氯虫苯甲酰胺的抗性最高，番茄潜叶蛾对杀虫剂的抗性与解毒酶活性无关。本研究的结果对番茄潜叶蛾的田间防治和杀虫剂抗性治理具有指导意义。

Susceptibility of Xinjiang and Yunnan populations ofTuta absoluta(Lepidoptera:Gelechiidae) to six insecticides and its relationship with detoxification enzyme activities

【Aim】 The South American tomato pinworm, Tuta absoluta, is a newly invadeddevastating pest in China, causing severe damage to tomatoes. However, the current statusof insecticide resistance in newly invaded T. absoluta populations in China has not beenreported. The objective of this study is to clarify the susceptibility of the fieldpopulations of T. absoluta from Xinjiang and Yunnan to six commonly used insecticides andits relationship with the activities of detoxification enzymes. 【Methods】 Laboratorytoxicities of six frequently used pesticides to the 2nd instar larvae of Xinjiang andYunnan populations of T. absoluta were tested by using leaf-dip method. The synergisticeffects of three synergistic agents including the CYP450 inhibitor piperonyl butoxide(PBO), the esterase inhibitor triphenyl phosphate (TPP) and the GST inhibitor diethylmaleate (DEM) on chlorantraniliprole were determined in the bioassay against the 2nd instarlarvae of T. absoluta, and the activities of detoxification enzymes including cytochromeP450-dependent monooxygenase (CYP450), glutathione S-transferase (GST) andcarboxylesterase (CarE) in the 2nd instar larvae of the laboratory susceptible populationand resistant field population (Xinjiang population) of T. absoluta were determined byenzyme activity assay, to ascertain the relationship of insecticide resistance withdetoxification enzyme activities. 【Results】 The susceptibility of Yunnan population of T.absoluta to the six insecticides from high to low was emamectin benzoate, chlorfenapyr,spinosad, indoxacarb, chlorantraniliprole, and beta-cypermethrin, while that of Xinjiangpopulation to the six insecticides from high to low was emamectin benzoate, chlorfenapyr,chlorantraniliprole, spinosad, indoxacarb, and beta-cypermethrin. Compared with thelaboratory susceptible population, both Yunnan and Xinjiang populations showed the highestlevel of resistance to chlorantraniliprole, with the resistance ratios of 212.7 and 169.3,respectively. The bioassay results revealed that the three synergistic agents PBO, TPP andDEM showed no obvious synergistic effect on chlorantraniliprole. The enzyme activity assaysshowed that the activities of CYP450, GST and CarE in the 2nd instar larvae between thelaboratory susceptible population and resistant field population of T. absoluta were not significantly different. 【Conclusion】 Both Xinjiang and Yunnan populations of T. absolutashow different levels of resistance to the tested six pesticides, with the highestresistance level to chlorantraniliprole, and the insecticide resistance of T. absoluta isunrelated to the activities of detoxification enzymes. The results of this study providevaluable information for the field control and insecticide resistance management of T.absoluta.