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.