增效混剂延缓棉铃虫对菊酯农药抗性机制的研究

THE MECHANISMS OF SYNERGISTIC INSECTICIDE MIXTURE TO DELAY DEVELOPMENT OF PYRETHROID RESISTANCE IN COTTON BOLLWORM

用同位素标记体壁穿透测定法及不同种群神经敏感性电生理测定法,进行了增效混剂延缓棉铃虫对菊酯抗性机制的初步研究。结果表明,与抗性生物汰选相一致,显示出药剂对增效菊酯混剂汰选种群比对菊酯单剂汰选种群的棉铃虫体壁穿透率高、神经敏感性也高的特点。证明了混剂延缓棉铃虫抗药性确与体壁穿透率和神经敏感性有关,有机制存在,这就为使用增效混剂进行棉铃虫抗性治理的措施打下了部分理论基础。

The development of insecticide resistance of cotton bollworm, Helicoverpa armigera, was much slower when selected by synergistic insecticide mixtures than by pyrethroid alone. Two mechanisms for delaying resistance were studied by corresponding methods, which included the penetration rate of pyrethroid by 14C-labled radioassay method, and the nerve sensitivity to pyrethroid by electrophysiological method. It was proved that the delayed resistance was related to the delayed penetration of pyrethroids, and the decreased nerve sensitivity to pyrethroid in the larvae of cotton bollworm. These results were useful for explaining the reasons of applying synegistic insecticide mixtures in insecticide resistance management programs of cotton bollworm.