杀虫剂对棉铃虫初孵幼虫击倒性研究

Study on Knockdown Activity of Insecticides to Cotton Bollworm Neonates

采用药膜法测定了１４种药剂对棉铃虫抗性与敏感种群初孵幼虫的击倒速度，结果表明，同种药剂对抗性和相对敏感种群的同日龄幼虫击倒速度差异不大，而不同药剂的击倒速度差异明显。药剂对１日龄幼虫略快于２日龄幼虫，但差异也不明显。以菊酯类杀虫剂、灭多威及少数有机磷杀虫剂如毒死蜱、甲基毒死蜱、甲基对硫磷的击倒速度最快，另一些有机磷杀虫剂如久效磷、丙溴磷、辛硫磷、甲丙硫磷、丙硫磷、甲胺磷则击倒速度较慢，以硫丹击倒速度为最慢，ＫＴ５０在３０分钟左右。

The knockdown activity of 14 insecticides to the neonates of cotton bollworm resistant population and sensitiue population was revealed in detail with residule method.The results showed that the discrepancy in the rate of knockdown of the same insecticides to larvae of the same instar were unclear whereas that between different insecticides were distinct among them,the knockdown activity of pyrethroids,methomyl and some organophosphorus insecticides such as chlorpyrifos-methyl,chlorpyrifos,parathion-methyl are most powerful,while that of endosulfan is weakest,with KT 50 around 30 minutes.The knockdown speed of other organophosphorus such as profenofos,monocrotophos,phoxim,sulprofos prothiophos,methamidophos are slower than others.