不同温湿度下绿僵菌对红缘天牛幼虫致病力的影响

Pathogenicity of the Metarhizium anisopliae to Asias halodendri larvae at different temperature and humidity conditions

在实验室内测定不同温、湿度下绿僵菌Metarhizium anisopliae对红缘天牛Asias halodendri幼虫的致病力的影响。分别在5个温度、5个湿度梯度下,研究温湿度对绿僵菌对红缘天牛幼虫的致病力影响。28℃、相对湿度>90%是绿僵菌感染红缘天牛的最佳温度和湿度条件。在28℃条件下,5 d后的幼虫的校正死亡率高达94.4%,其致死中时(LT50)约为8 h,明显短于其他各组,且幼虫僵虫率最高。温度高于或低于28℃条件时,绿僵菌对红缘天牛幼虫致死率都会减弱,致死中时(LT50)均在33 h以上,僵虫率也降低。相对湿度越大,对幼虫致病力越强。相对湿度>90%时的致死效果最好,校正死亡率和僵虫率分别为99.3%和50%,此湿度条件下致死速率也最快,LT50仅为35.3 h;相对湿度50%-60%时,幼虫校正死亡率和僵虫率显著降低,LT50约为122 h。

Effects of different temperature and humidity on the pathogenicity of Metarhizium anisopliae to Asias halodendri larvae were tested in the laboratory. Pathogenicity of Metarhizium anisopliae to Asias halodendri larvae at the five temperature gradient. The research results show that 28℃ is the best temperature. At 28℃, M. anisopliae showed the best effect of death to A. halodendri larvae, the corrected mortality rate as high as 94. 4%, and stiff insect rate was the highest. The death velocity was the highest and the LT50 value was about 0. 3 d ; At higher or lower temperature, the infected effects were weakened, and the LT50 value were about 2 d. Relative humidity was higher, the pathogenicity of A. halodendri larvae was higher. At RH of （ 〉 90）%, M. anisopliae showed the best effect of death to A. halodendri larvae, the corrected mortality and stiff insect rate were 99.3% and 50% respectively, the death velocity was the highest and the LT50 value was 1.47 d; When RH was 50% -60%, the corrected mortality, stiff insect rate and death velocity descended, the LT50 value was about 5 d.