氰戊菊酯、辛硫磷及其混剂对棉铃虫解毒代谢酶的影响

Effects of Fenvalerate, Phoxim and Their Mixture on Metabolic Enzymes in Helicoverpa armigera Hübner

采用点滴法,筛选出对抗性棉铃虫具有明显增效作用的氰戊菊酯、辛硫磷杀虫剂混剂。用氰戊菊酯、辛硫磷及其混剂的亚致死剂量分别对棉铃虫幼虫进行处理,以丙酮处理为对照,24h后测定其代谢酶活性。结果表明:1多功能氧化酶催化的环氧化酶活性和O-脱甲基酶活性在棉铃虫敏感(S)品系中易被诱导,尤以前者最明显,而在抗性(R)品系中在一定程度上被抑制。2药剂对非特异性酯酶产生不同程度的抑制现象,尤以辛硫磷抑制最明显,对羧酸酯酶的抑制作用强于对非特异性酯酶的抑制作用,对R品系的抑制作用强于对S品系的抑制作用。3药剂对谷胱甘肽S-转移酶活性的影响与对谷胱甘肽含量的影响趋势相一致,在S品系中均产生抑制作用,以混剂最明显,而在R品系中只有氰戊菊酯产生抑制作用,辛硫磷和混剂却表现出诱导作用。

Synergism of the mixture of fenvalerate and phoxim on the 3rd instar larvae of R strain of Helicoverpa armigera Hübner was assayed by topical application and the synergism was obvious. In vivo effect on metabolic enzymes in H.armigera was studied by sublethal dose of fenvalerate, phoxim and their mixture 24 h after treatment. The results showed that: ① The activities of mixed function oxidase in O-demethylation and aldrin epoxidation were easily induced in S strain, especially for the latter, but they were inhibited in R strain. ② All treatments showed inhibition to the activities of esterases to some degree, and the inhibition by phoxim was the strongest. The inhibition of carboxylesterase was stronger than that of non-specific seterase and more obvious in R strain than in S strain. ③ Effect on the activities of glutathione S-transferases coincided with the quantity of glutathione (GSH). Three insecticides showed inhibition to the activities of GST in S strain, most obvious for the mixture; but in R strain, only fenvalerate showed inhibition, phoxim and mixture showed induction.