三株球孢白僵菌对小菜蛾室内毒力测定

Virulence of Three Strains of Beauveria bassiana aganist Plutella xylostella

为发掘生防潜力,以小菜蛾为供试昆虫,对从湖北省恩施州所采草地贪夜蛾僵蚕体上分离获得的三株球孢白僵菌Bbyn-1、Bbyn-2和Bbyn-3进行室内毒力测定。结果表明,当孢子悬浮液浓度为1×10^(8)个/mL时,接种7 d后菌株Bbyn-1的毒力最高累计死亡率为97.66%;当孢子悬浮液浓度为1×10^(8)个/mL、接种量150μL时,接种7 d后菌株Bbyn-1的毒力最高为99.67%;浸虫法接种7 d后菌株Bbyn-3的毒力最高为96.94%;涂抹法接种7 d后菌株Bbyn-2的毒力最高为93.71%。与球孢白僵菌菌株Bbyn-2和Bbyn-3相比,菌株Bbyn-1有较高的致病力,具有进一步研究和开发的潜力。

Three strains of Beauveria bassiana,Bbyn-1,Bbyn-2,and Bbyn-3 isolated from silkworm of Spodoptera frugiperda(Enshi,Hubei Province)were bioassayed against the second instar larvae of Plutella xylostella.The results showed that the cumulative mortality of Bbyn-1 was 97.66%in the 108 conidia/mL.When the inoculation volume is 150μL,the cumulative mortality of Bbyn-1 can rise up to 99.67%.After inoculating for 7 days,the cumulative mortality of Bbyn-3 was the highest 96.94%by the immersion method,and the cumulative mortality of Bbyn-2 was 93.71%by the smear method.The results also showed that the three strains of Beauveria bassiana had certain effect to Plutella xylostella.The virulence was higher than Bbyn-2 and Bbyn-3 strain,especially Bbyn-1 strain,which has the potential for further research and development.