Bt菌株对斜纹夜蛾幼虫的毒力测定

为给斜纹夜蛾的生物防治提供依据,测定了Bt(K-1)菌株对斜纹夜蛾3龄幼虫的毒力。即采用苏云金杆菌K-1菌株原液及其稀释50、100、300、500、800、1000倍液浸泡新鲜烟叶5min,室内晾干后喂食斜纹夜蛾3龄幼虫。结果表明,原液的处理效果最好,处理后72h该虫全部死亡;感染时间的长短对毒性有显著影响,在一定时间内,随着感染时间的延长,苏云金杆菌对斜纹夜蛾3龄幼虫的毒性有明显提高。

Toxicity Determination of Bt Strain to Prodenia litura Larva

In order to control Prodenia litura effectively, the toxicity of Bt strain K-1 to 3-instar larvae of Prodenia litura was determined. The fresh tobacco leaves were dipped in undiluted K-1 ferment filtrate and dilutions of 50, 100, 300, 500, 800, 1000 for 5 minutes, then air dried indoors, and 3_instar larvas of Prodenia litura were fed with such treated tobacco leaves. The results indicated that the effect of treatment with undiluted K-1 ferment filtrate was the best and all of the larvae died in 72h after treating. The duration of infected time affected the toxicity prominently, the toxicity of Bt to Prodenia litura was enhanced obviously with the prolongation of infected time.