多杀霉素和甲氨基阿维菌素苯甲酸盐对小菜蛾的室内生测及田间药效评价

Toxicity Tests of Spinosad and emamectin benzoate on Plutella xylostella Linne

分别采用触杀毒力法和摄食毒力法测定了多杀霉素和甲氨基阿维菌素苯甲酸盐对小菜蛾的室内生物活性,研究结果表明:药后48h,甲维盐的触杀活性和胃毒活性均好于多杀霉素。另外,2种药剂的胃毒活性均好于触杀活性。田间药效试验结果表明,多杀霉素2.5%悬浮剂对小菜蛾幼虫表现出优良的防治效果。在小菜蛾发生期,以15.00～19.99ga.i./hm2兑水均匀喷雾,施药后7d,防治效果可达90%以上。用甲氨基阿维菌素苯甲酸盐2%乳油(对照药剂)常规使用剂量喷雾,最高防治效果达85%以上,稍逊于多杀霉素2.5%悬浮剂。

The toxicities of spinosad and emamectin benzoate on 3rd larvae of Plutella xylostella Linne were tested with dipping method and ingestion method.The results showed that emamectin benzoate EC had better contact and stomach activities at 48h after treatment. Moreover, the stomach activities of the two pesticides were better than their contact activities. The results of field trials showed that spinosad 2.5% SC had a excellent control effect on Plutella xylostella Linne. The control effect was over 90% with dosages of 15.00-19.99g （a.i.） /hm2. The control effect of emamectin benzoate 2% EC was over 85% after spraying with regular dosage, that was worse than 2.5% spinosad SC.