溴虫腈对甜菜夜蛾的毒力及应用研究简报

Study on the Toxicity and the Effectiveness of Chlorfenapyr to-Spodoptera exigua

室内毒力测定结果表明,溴虫腈EC对甜菜夜蛾卵的孵化有一定的抑制作用,但作用较小,20mg/L药液浸卵后,卵孵化抑制率为43.11%。溴虫腈EC对甜菜夜蛾1～2龄幼虫的毒力很高,3龄后随着虫龄的增大,甜菜夜蛾对溴虫腈的敏感性显著降低。室内钵栽试验表明,20mg/L溴虫腈EC对甜菜夜蛾2龄幼虫的减退率在91.43%～100%之间,持效期15d以上。田间试验表明,溴虫腈对甜菜夜蛾有优异的防治效果,每公顷施用5%溴虫腈EC1200mL,防治效果在95%以上,持效期为20d。

The result of the test in laboratory showed that the control rate of hatching to Spodoptera exigua (Hübner) was 43.11% with 20 mg/L chlorfenapyr EC. The toxicity of chlorfenapyr to S.exigua deduced with the increase of instar. Larva in 1～2 instar was the most sensitive. In pot test,the mortality was 91.43%～100% and residual activity was over 15 days at concentration of 20 mg/L.The result of trial in field indicated that the control effects of 5% chlorfenapyr EC to S. exigua at 1 200 mL/hm2 was 95% and the high effectiveness was maintained for 20 days.