35％双扑乳油对菜青虫和棉蚜的毒力及作用机理研究

Toxicity and Synergistic Mechanism of A Combined Insecticide Shuangpu to Pieris Rapae and Aphis Gossypii

以棉蚜和菜青虫为试虫，采用ＦＡＯ推荐的浸渍法和点滴法，测定了３５％“双扑”乳油及各组成单剂对其毒力。并对菜青虫的乙酰胆碱酯酶活性进行了测定，探讨了“双扑”的作用机理。结果表明：“双扑”及单剂Ａ、Ｂ、Ｃ对棉蚜的ＬＣ５０分别为８．８３ｐｐｍ、５．２９ｐｐｍ、３２．１３ｐｐｍ、２９．７８ｐｐｍ，对菜青虫的ＬＣ５０分别为６．８８ｐｐｍ、１９．２６ｐｐｍ、４７．９２ｐｐｍ、１２３．５８ｐｐｍ。对两种试虫的共毒系数分别为２０６．９和７３３．０２，说明“双朴”有非常显著的增效作用。乙酰胆碱酯酶活性测定结果表明，“双扑”比各单剂有更强的抑制作用，稀释１０００倍抑制达８８．４６％，说明对乙酰胆碱酯酶活性的抑制是“双扑”增效作用机理之一。

Toxicity of a insecticide mixture Shuangpu and its components to Pieris rapae andAphis gossypii were tested in laboratory.The results indicated that the co-toxicity coefficien-cy of Shuangpu were 733.02 and 206.90 to Pieris rapae and Aphis gossypii,respectively.Itwas clear that the mixture Shuangpu had very strong synergistic action to the pests. TheSynergistic mechanism was also evaluated by analysing the inhabitory AChE.