Bti对三带喙库蚊的杀伤效果及温度的影响

目的 对苏云金杆菌以色列亚种(Bacillus thuringiensis israelensis,Bti)杀伤三带喙库蚊幼虫的效果进行生物测定,并探讨温度对Bti杀伤效果的影响.方法 首先利用概率分析方法对Bti水分散颗粒剂作用于三带喙库蚊幼虫的杀伤效果进行生物测定,然后检测和比较在不同温度下Bti对三带喙库蚊幼虫的杀伤效果,明确温度对Bti灭蚊效果的影响.结果 Bti对三带喙库蚊幼虫的灭杀起效快,12h内即显示很强的杀伤效果.LC50和LC95分别是171.72 IU/L和646.60 IU/L.24h内温度(16～37℃)对杀伤效果有一定的影响,适当提高环境温度,可以增强Bti对蚊幼虫的杀伤效果.结论 三带喙库蚊幼虫对Bti较为敏感,一定范围内升高温度可以提高Bti的起效速度和杀伤效果.本研究结果提示,Bti是三带喙库蚊防制的理想生物杀虫剂.

Killing effect of Bacillus thuringiensis israelensis on Culex tritaeniorhynchus larvae and effect of temperature on the killing.

Objective To study the Killing effect of Bacillus thuringiensis israelensis （Bfi） on Culex tritaeniorhynchus larvae and the effect of temperature on the killing. Methods Firstly, bioassay was carried out to test the mortality of Culex tritaeniorhynchus larvae after Bti treatment by probit analysis and the killing effect of Bti on C tfftaeniorhynchus under different temperature was investigated. Results C. tfftaeniorhynchus larvae were quickly killed by Bti 12 hours after treatment with Bfi LCs0 and LC95 were 171.72 IU/L and 646.60 IU/L respectively. And, the killing etficiency was significantly affected by temperature within the range of 16~37~C in 24 hours. But there was no significant difference between groups 12h and 24h post treatment at 28~C and 37~C. Conclusion Culex tritaeniorhynchus larvae are sensitive to Bti. The Killing Effect of Bti on C tfitaeniorhynchus larvae could be accelerated and improved by enhancemnent of the emperature in a limited range. The results show that Bti is a kind of ideal larvicide to control C tritaeniorhynchus.