马铃薯桃蚜对拟除虫菊酯类杀虫剂的敏感性及其体内羧酸酯酶活性研究

为明确内蒙古马铃薯主要种植区马铃薯桃蚜的抗药性水平及抗性形成机制,采用室内生物测定方法,检测了内蒙古呼和浩特市及呼和浩特武川县马铃薯桃蚜田间种群(分别简称为呼市种群和武川种群)和室内饲养未接触任何药剂的马铃薯桃蚜敏感种群对7种拟除虫菊酯类杀虫剂的敏感性,并对供试各种群桃蚜的羧酸酯酶(CarE)活性进行了研究。结果表明:相对于敏感种群,呼市种群和武川种群对氯氰菊酯均产生了高水平抗性(抗性倍数为74.11和549.4);呼市种群对联苯菊酯产生了中等水平抗性(16.03倍),对氰戊菊酯、高效氯氰菊酯和高效氯氟氰菊酯仍保持敏感(1.00~4.00倍);武川种群对溴氰菊酯(10.14倍)、甲氰菊酯(26.46倍)和联苯菊酯(33.74倍)处于中等抗性水平,对高效氯氰菊酯、氰戊菊酯和高效氯氟氰菊酯仍较为敏感(50值分别为0.54、1.07和0.93 nmol/L。三唑磷分别与高效氯氰菊酯和溴氰菊酯联用可显著增强其毒力,表明三唑磷与这两种拟除虫菊酯类药剂复配在武川和呼市马铃薯桃蚜防治中具有很好的应用潜力。

Study on susceptibility to pyrethroids and carboxylesterase activity in Myzus persicae on potato

The objective of this study is to survey the resistance level of peach aphid Myzus persicae(Sulzer) in Hohhot and Wuchuan area, and investigate the insect resistance mechanism. The resistance of M. persicae to seven pyrethroids was determined by bioassay, and the carboxylesterase activity of this pest was also studied. The results show that relative to the sensitive population, Hohhot and Wuchuan populations have developed the highest resistance levels to cypermethrin(74.11 and 549.4, respectively). Hohhot population developed moderate resistance to bifenthrin(16.03), and kept susceptible to fenvalerate, beta-cypermethrin and beta-cyhalothrin(from 1.00 to 4.00). Wuchuan population has developed moderate resistance to deltamethrin(10.14), fenpropathrin(26.46) and bifenthrin(33.74), and demonstrated susceptible to beta-cypermethrin, fenvalerate and beta-cyhalothrin(RR<5.00). Further study was conducted on the carboxylesterase activity of M. persicae.Wuchuan and Hohhot populations illustrated significantly higher activity than the sensitive population. Carboxylesterase activity of Wuchuan, Hohhot and sensitive populations were all strongly inhibited by triazophos, with IC₅₀ value of 0.54, 1.07 and 0.93 nmol/L, respectively. Bioassays showed that triazophos increased the toxicity of both beta-cypermethrin and deltamethrin when they were applied as a mixture, which showed that the combination application of triazophos and those two pyrethroids have the potential in the control of M. persicae in Wuchuan and Huhhot areas.