Bacillus thuringiensis 살충제 개발에 관한 연구 - B. thuringiensis serovar kurstaki 살충제와 내독소의 치사성과 안전성 연구 -

Studies on the Development of the Bacillus thuringiensis - Lethality and safety tests of the endotoxin and the pesticide of B. thuringiensis serovar kurstaki -

The lethality to Pieris raepi larvae and the safety tests to mice of the endotoxin crystals and the pesticide of B thuringiensis serovar kurstaki were carried out. The LD50 of the endotoxin (3.9$\times$10$^9$ spores/$m{\ell}$) appeared to be 1$\mu$g and that of the pesticide (2.6$\times$10$^9$ spores/$m{\ell}$) was about 9 $\mu$g. When the endotoxin solution and the pesticide were injected to the mice's intraperitoneal cavities, 10 to 20% of the mite were dead. Also in the case of intracerebral injection 20% of the mice were dead at the doses of 7.8$\times$10$^3$ spores and 100% of the mice were dead at the concentration of 7.8$\times$10$^8$ spores. but the mice in the oral, subcutaneous and inhalation treatment groups were safe and healthy. When the pesticide applied to the cabbage field for raepi larvae, 52 to 65% of the larvae in the field were killed in 4 days postapplication.