噻虫嗪对褐飞虱的毒力及解毒代谢酶活性的影响

【目的】明确噻虫嗪对褐飞虱Nilaparvata lugens的抗药性及解毒代谢酶活性的影响。【方法】采用稻苗浸渍法测定褐飞虱温室种群对吡虫啉、噻虫嗪、噻嗪酮和毒死蜱的抗药性,以及对新型防控药剂氟啶虫胺腈和三氯苯嘧啶的敏感性;研究增效剂胡椒基丁醚(PBO)、马来酸二乙酯(DEM)和磷酸三苯酯(TPP)对噻虫嗪的增效作用;测定了羧酸酯酶、谷胱甘肽S-转移酶和细胞色素P450s酶活性。【结果】褐飞虱种群对噻虫嗪表现出高水平抗性,抗性倍数达到277.92倍,对氟啶虫胺腈和三氟苯嘧啶仍处于敏感水平,对三氟苯嘧啶无交互抗性。PBO对噻虫嗪的增效作用最强,增效倍数为1.99倍。温室抗性种群的细胞色素P450s活性达到4.70×10-3 IU/mg,为室内敏感品系的2.13倍。【结论】细胞色素P450s活性的增强可能是褐飞虱对噻虫嗪产生代谢抗性的主要原因。氟啶虫胺腈和三氟苯嘧啶轮换使用可有效防控褐飞虱。

Effects of thiamethoxam on toxicity and detoxification metabolic enzyme activity of Nilaparvata lugens

Objective To clarify the effects of thiamethoxam on resistance and detoxification metabolic enzyme activity of Nilaparvata lugens.Method The resistance levels of N. lugens population in greenhouse against four insecticides (imidacloprid, thiamethoxam, buprofezin, chlopyrifos) and the sensitivities to two new types of insecticides (sulfoxaflor, triflumezopyrim) were measured using rice seedling immersion method. The synergistic effect of three synergists piperonyl butoxide (PBO), diethyl maleate (DEM), triphenyl phosphate (TPP)] on thiamethoxazine, and three detoxification enzymes (carboxylesterase, qlutathione S-transferase, cytochrome P450s) activities were analyzed.Result N. lugens population showed high resistance to thiamethoxam with the resistance ratio of 277.92 folds, sensitive to sulfoxaflor and triflumezopyrim, and no cross resistance to triflumezopyrim. PBO had the strongest synergistic effect on thiamethoxam with the synergistic ratio of 1.99. Cytochrome P450s activity of greenhouse population reached 4.70×10^-3 IU/ mg, which was 2.13 folds to that of susceptible strain.Conclusion The increased activity of cytochrome P450s could be the main factor resulting in the metabolic resistance of N. lugens to thiamethoxam. The alternate use of sulfoxaflor and triflumezopyrim can effectively control the occurrence of N. lugens.