中文摘要：

目的研制苏云金杆菌以色列亚种（Bacillus thuringrensis var.israelesis,Bti）颗粒剂新剂型并测定其杀灭蚊幼虫效果。方法分离筛选Bti菌株,采用载体湿法包衣试制成Bti颗粒剂。通过模拟现场试验、持效性试验和外环境试验分别测定该制剂对蚊幼虫杀灭效果、持效期及在外环境的稳定性。结果野外分离的Bti菌株对库蚊、伊蚊幼虫的LC50分别为0.461 0μl/L和1.713 3μl/L。试制的216 ITU/mg Bti颗粒剂1～3 g/m2施药后淡色库蚊幼虫死亡率为83.3%～100%,3～5g/m2埃及伊蚊幼虫死亡率达72.7%～100%。0.5 g/m2颗粒剂处理的水体13 d后接种3龄淡色库蚊幼虫死亡率仍高达55.3%。外环境试验中,216 ITU/mg Bti颗粒剂2～4 g/m2对蚊幼虫1～3 d防治效果达92.4%～100%,20 d达51.6%～75.7%。结论采用分离菌株研制的Bti颗粒剂具有较好的杀灭蚊幼虫效果,在外环境中试用持效期长且稳定性好。

英文摘要：

Objective To develop a new formulation of Bacillus thuringrensis var. israelesis （Bti） granules and assess its ef- fect on mosquito control. Methods The Bti granule formulation was produced by coating Bti liquid on the surface of the carrier. and imitation tests, persistence tests and field tests were carried to assess its mosquito larvicidal effect, extended period and stabil- ity. Results A strain of Bti isolated from field had high toxicity to mosquito larvae and its LCs0 values for larvae of Culex pipiens pallens and Aedes aegypti were 0.461 0 μl/L and 1.713 3 ~I/L respectively. The developed 216 ITU/mg Bti granules had a control effect of 83.3%-100% to larvae of C. pipiens pallens at the dosage of 1-3g/m^2, and 72.7%-100% to A. aegypti at the dosage of 3-5g/ m^2. When the 3rd instar larvae of C. pipiens pallens were put in the water that was treated with the granules at the dosage of 015 g/m^2 13 days before, the larval mortality still reached to 55.3%. The field tests showed that with the treatment of 2-4 g/m^2 Bti granules, the control effects on the larvae were high from 92.4% to 100% within the first 3 days and about 51.6%-75.7% after 20 days. Conclusion The developed new formulation of Bti granules with the isolated strain has a preferable control effect on mosquito larvae and reveals a longer persistence and better stability than liquid formulation in the field tests.