6种杀虫剂对小菜蛾的室内毒力及田间防效

目的]筛选出防治小菜蛾的有效药剂。方法]采用点滴法测定了甲氨基阿维菌素苯甲酸盐等6种杀虫剂对小菜蛾3龄幼虫的室内毒力,采用对水叶面喷雾法测定了其中杀虫效果较好的5种制剂对小菜蛾的田间防效。结果]甲氨基阿维菌素苯甲酸盐对小菜蛾3龄幼虫的室内毒力最高,其LC50为0.17 mg/L;其次为氯虫苯甲酰胺、虫螨腈及多杀菌素,其LC50依次为0.44、0.84、1.25 mg/L;丁醚脲和氰氟虫腙的毒力最低,其LC50分别为10.43和11.17 mg/L。田间施药后6 d,5%氯虫苯甲酰胺SC 1 000倍液对小菜蛾的防效较好,高达82.33%;5.7%甲氨基阿维菌素苯甲酸盐WG 2 500倍液、10%虫螨腈SC 1 500倍液、25%丁醚脲EC 1 500倍液及2.5%多杀菌素EW1 500倍液难以控制其危害,防效分别为60.50%、58.02%、55.64%和55.40%。结论]为小菜蛾的有效控制提供了理论依据。

Toxicity and Field Control Efficacy of Several Insecticides against Plutella xylostella

Objective] The study aimed to screen out the insecticides for controlling Plutella xylostella(L.) effectively.Method] The toxicity of emamectin benzoate etc 6 pesticides to Plutella xylostella were determined with topical application method,and the field plot experiment with foliar spraying by insecticides added to the water was conducted for determining the field control efficacy of five better insecticides to Plutella xylostella.Result] The results showed that the LC50 of emamectin benzoate was 0.17 mg/L,and the LC50 of chlorantraniliprole was 0.44 mg/L.But the LC50 of 4 other insecticides were higher than emamectin benzoate and chlorantraniliprole,which were 0.84 mg/L,1.25 mg/L,10.43 mg/L and 11.17 mg/L.Chlorantraniliprole was the best choice to control of Plutella xylostella in the field after 6 days,which was 82.33%,and the others were 60.50%,58.02%,55.64% and 55.40%.Conclusion] The reference for control the Plutella xylostella was provided.