不同温湿度下白僵菌对红缘天牛幼虫致病力的研究

为了寻找白僵菌(Beauveria bassiana)对红缘天牛(Asias halodendri)的最佳作用条件,测定不同的温、湿度条件下,白僵菌作用于红缘天牛幼虫后,幼虫的死亡情况.结果表明:(1)31℃是白僵菌感染红缘天牛幼虫的最佳温度.该温度下,幼虫在5 d的校正死亡率高达77.78%,致死速率快,LT50仅为0.121 d,僵虫率为46.67%,显著高于其他各组,温度增高或降低,都会使致死速率和僵虫率降低;(2)相对湿度>90%时,白僵菌对红缘天牛幼虫的致死效果最好,此时的校正死亡率和僵虫率分别为100%和63.33%,致死速率也最快,LT50为1.017 d,相对湿度降低时,幼虫的校正死亡率和僵虫率显著降低.

Pathogenicity of Beauveria bassiana to Asias halodendri larvae under different temperatures and humidities

In order to obtain the optimal treatment conditions of Beauveria bassiana on Asias halodendri,the death of Asias halodendri larvae imposed to Beauveria bassiana were tested under different temperatures and humidities.The results showed that：（1） At 31 ℃,Beauveria bassiana showed the best lethal effect on Asias halodendri larvae,the corrected mortality rate was as high as 77.78% in 5 d,and the muscardine cadaver rate was 46.67%.The lethal rate was the highest and the LT50 value was 0.121 d.These data were better than the other groups evidently.At higher or lower temperature,the infected effects were weakened.（2）When relative humidity（RH）was higher than 90%,Beauveria bassiana showed the best lethal effect on Asias halodendri larvae,the corrected mortality rate and muscardine cadaver rate was 100% and 63.33% respectively,the lethal rate was the highest and the LT50 value was 1.017 d.When RH was relatively lower,the corrected mortality rate and muscardine cadaver rate decreased evidently.