氟虫腈和阿维菌素对小菜蛾及其寄生蜂半闭弯尾姬蜂的毒力研究

通过药膜法和喷雾法分别测定了氟虫腈和阿维菌素对小菜蛾及其天敌半闭弯尾姬蜂的室内毒力和田间药效。结果表明,氟虫腈和阿维菌素对小菜蛾幼虫具有很高的毒力和良好的田间防治效果,致死中浓度LC50分别为1.105 mg/L和1.602 mg/L,田间防效分别为90.91%和82.02%;氟虫腈和阿维菌素对半闭弯尾姬蜂的LC50分别为2.281 mg/L和6.036 mg/L,选择指数分别为2.064和3.768,对此天敌较为安全;但是田间药效试验却表明氟虫腈和阿维菌素对半闭弯尾姬蜂具有相当的负面影响。

Study on Virulence of Fipronil and Avermectins to Plutella xylostella and Its Parasite Diadegma semiclausum

The virulence of Fipronil and Avermectins to Plutella xylostella and its natural enemy Diadegma semiclausum was tested by residual smearing method in the laboratory,and by spray method in the field.The results showed that Fipronil and Avermectins had high toxicity to the larvae of P.xylostella(LC50 was 1.105 mg/L and 1.602 mg/L respectively) and high control efficacy against the insect pest in the field(control effect was 90.91% and 82.02% respectively).The LC50 of Fipronil and Avermectins to D.semiclausum was 2.281 mg/L and 6.036 mg/L respectively.The selective toxicity indexes of Fipronil and Avermectins were 2.064 and 3.768 respectively,it indicated that this two insecticides were safe to D.semiclausum.But the results of field efficacy trials showed the side-effects of Fipronil and Avermectins on D.semiclausum were obvious.