吡蚜酮与异丙威复配对褐飞虱的增效作用和田间防治

Biological Activity and Control Effect of Nilaparvata lugens on the Pymetrozine and Isoprocarb and Mixed Pesticides

室内生测结果表明:吡蚜酮与异丙威质量比为1﹕2,对褐飞虱3龄若虫具有较高的生物活性,其LC50值为11.01mg/L,共毒系数为166.65,表现出明显的增效作用;按此配比加工成30%吡蚜·异丙威WP(有效成分:吡蚜酮10%、异丙威20%)。田间防治结果表明:该混剂对褐飞虱表现出良好的速效性和持效性。药后3d,30%吡蚜·异丙威WP450～600g/hm2对褐飞虱若虫的防治效果为90.83%～94.94%,药后21d,30%吡蚜·异丙威WP450～600g/hm2对褐飞虱若虫的防治效果仍有87.60%～89.32%,均好于对照药剂吡蚜酮、异丙威对褐飞虱的防治效果。从防效和经济的角度考虑,30%吡蚜·异丙威WP推荐剂量为450g/hm2,防治适期宜在褐飞虱若虫高峰期。

The result of the biological activity showed that the LC50 and co-toxicity coefficient（CTC） of the mixture of pymetrozine and isoprocarb at the ratio of 1：2, which had excellent effect against the 3 th larval stage of Nilaparvata lugens, were 11.01 mg/L and 166.65, respectively. The mixture indicated addition effect, obviously. The results of field trials of pymetrozine and isoprocarb 30% WP which content pymetrozine and isoprocarb at the ratio of 1：2, showed that the mixture reagent had favorable quick-acting and persistent effects. The effect of pymetrozine and isoprocarb 30% WP at the dose of 450-600 g/ha was 90.83-94.94% after 3 days, and was still 87.60-89.32% after 21 days, which were all much better than pymetrozine or isoprocarb. So pymetrozine and isoprocarb 30% WP at the dose of 450 g/ha is recommended for controlling Nilaparvata lugens.