The bacterial suspensions of eight strains of Bacillus thuringiensis (Bt) against the Plodia interpunc-tella larva have been carried out in this paper. The five strains of high effective Bt were selected among 8 strains. After the insecticidal crystal protein (ICP) of the 5 strains has been extracted, the toxicity of ICP to the larva of P. Inter-punctella have been assayed. The results indicated that the lethality of the larva was 100% by using ICP of SCI-B3 strains at 0.06 mL/g concentration. It was more than 70% lethality by using ICP of Bt33 strains,and it was less than 22. 2% lethality by using ICP of other 3 strains,at same concentration.%根据8株苏云金芽孢杆菌(Bacillus thuringiensis,简称Bt)的菌悬液对印度谷螟幼虫的生物测定结果,筛选出5株对该幼虫致死作用较好的Bt菌株.提取出5株Bt菌株的杀虫晶体蛋白,再对印度谷螟幼虫进行生物测定,结果表明:0.06 mL/g(饲料)的SC1 - B3菌株杀虫晶体蛋白对印度谷螟幼虫的致死率达到100％,同样浓度的Bt33菌株杀虫晶体蛋白对印度谷螟幼虫的致死率超过70％,其余3株Bt的杀虫晶体蛋白致死率较低,致死率小于22.2％,但对印度谷螟幼虫的羽化有明显的抑制作用.
展开▼
