不同地理来源的球孢白僵菌对甜菜夜蛾幼虫的致死效应

The lethal effect of Beauveria bassiana from different geological locations on the larvae of Beet Armyworm

为探讨不同地理来源的球孢白僵菌对甜菜夜蛾种群的控制效果,测试了3个地区4株球孢白僵菌菌株孢子悬浮液对甜菜夜蛾2龄幼虫的致死效应,并对其致死效果进行了时间-剂量-死亡率（TDM）模型拟合。结果表明：在处理后第4—7天球孢白僵菌菌株BD-038（河北保定）、2096N（上海）、菌株A（广东广州）、菌株B（广东广州）对甜菜夜蛾幼虫的致死中浓度（LC_（50））（单位：孢子/mL）分别为5.46×10^5—3.41×10^7、1.32×10^7—2.31×10^8、1.76×10^7—5.47×10^8、2.94×10^8—6.63×10^9,其中菌株BD-038在1×10^6—1×10^8孢子/mL的致死中时间（LT_（50））分别为6.4854—3.6689 d,菌株2096N和菌株A在1×10^8孢子/mL的LT_（50）分别为4.7565 d和5.2085 d。由此表明菌株BD-038对上海地区甜菜夜蛾幼虫具有较高的毒力。

To investigate the control effect of Beauveria bassiana on Spodoptera exigua （Hiibner）, beet ar- myworm, this paper tested the lethal effect of four strains of Beauveria bassiana from three different geological lo- cations on 2-instar larvae of beet armyworm, and fitted the lethal effect with the Time-Dose-Mortality （TDM） model. The results showed that the median lethal concentration （ LCs0 ） for the strain BD-038 （ Baoding city, He- bei province）, strain 2096 N （ Shanghai）, strain A （ Guangzhou city, Guangdong province） and strain B （ Guang- zhou city,Guangdong province）were 5.46×10^5-3.41×10^7、1.32×10^7-2.31×10^8、1.76×10^7-5.47×10^8、2.94×10^8-6.63×10^9 conidia/mL, respectively. The median lethal time （ LT50 ） of the strain BD-038 at the concentration of 1×10^6-1×10^8 were 6. 4854--3. 6689 d, strain 2096N and A at the concentration of 1×10^8 LT50 were 4. 7565 d and 5. 2085 d, respectively. From the above results it was concluded that the strain BD-038 has a high toxicity to beet armyworm in Shanghai ,which might provide a basis for further field control.