球抱白僵菌对中华按蚊的致病力测定

Study on the pathogenicity of Beauveria bassiana to Anopheles sinensis

目的测定球孢白僵菌对不同齡期和不同生境中华按蚊幼虫的致病力,探索球孢白僵菌对中华按蚊的生物防治潜能。方法中华按蚊按龄期和生境分为不同的处理组,采用球孢白僵菌孢子悬浮液处理,记录各处理组中华按蚊的累计死亡数,计算致死中时LTso。结果中华按蚊龄期越低,对球孢白傴菌的敏感性越高,处理10 d后,I.I、I龄幼虫死亡率达100%,与N齡幼虫和蛹死亡率比较差异有统计学意义(F=372.28,df=19,P<0.05)。与野外采集蚊虫相比,室内饲养中华按蚊死亡高峰期提前2~3d,不同栖境(BH、WS、DP、SX、M)按蚊幼虫的致死中时LTso分别为3.07.3.73.2.89.4.74.2.52 d,各组间幼虫累计死亡率比较差异有统计学意义(F=30.39,df=19,P<0.05)。结论实验室条件下的球孢白僵菌对中华按蚊各品系均有较强的致病力,有望用于中华按蚊的生物防治。

Objective To explore the virulence of Beauveria bassiana to larvae of Anopheles sinensis at different ages and in different habitats in order to provide a theoretical basis for expanding resources to biologically control mosquitoes.Methods A suspension of B.bassiana spores was used to treat larvae and pupae of An.sinensis which were divided in-to different treatment groups by age and habitat.The cumulative mortality rate of An.sinensis was recorded,and LT50 at the time of death was calculated.Results The earlier the instar of An.sinensis larvae,the greater the sensitivity to B.bassiana.After treatment with B.bassiana for 10 d,the mortality of the 1st instar,2nd instar,and 3nd instar larvae reached 100%.This rate was significantly higher than that of 4nd instar larvae or pupae(F=372.28,df=19,P<0.05).Compared to mosquitoes collected in the wild,An.sinensis bred indoors was more sensitive to B.bassiana,and death peaked 2-3 d earlier.The median lethal time(LT50)of An.sinensis in different habitats(BH,wS,DP,SX,and M)was 3.07 d,3.73 d,2.89 d,4.74 d,and 2.52 d,respectively.The cumulative mortality of larvae differed signifi-cantly among groups(F=30.39,df=19,P<0.05).Conclusion Under laboratory conditions,B.bassiana is highly pathogenic to An.sinensis strains,and this finding could be used to biologically control An.sinensis.