球孢白僵菌菌株Bb-2孢子侵染力和代谢产物毒力

Virulence of Spores and Fermentation Filtrates of Beauveria bassiana Bb-2

利用球孢白僵菌菌株Bb-2(Beauveria bassiana Bb-2)活体孢子和代谢产物对2龄小菜蛾(Plutella xylostella)幼虫和桃蚜(Myzus persicae)进行毒力测定。结果表明,菌株Bb-2在1.1×107、1.1×108、1.1×109个孢子/mL 3个浓度下,对2龄小菜蛾幼虫和桃蚜均表现出较高的侵染力。在高浓度(1.1×109个孢子/mL)条件下,2龄小菜蛾幼虫的4 d累计死亡率为75.0%,桃蚜的4 d累计死亡率为92.5%。在低浓度(1.1×107个孢子/mL)条件下,2龄小菜蛾幼虫的4 d累计死亡率为36.7%,桃蚜的4 d累计死亡率为47.7%。菌株Bb-2发酵液对2龄小菜蛾幼虫和桃蚜均有一定的活性,且对桃蚜的活性明显高于对小菜蛾的活性。

The virulence of Beauveria bassiana strain Bb-2 to Plutella xylostella and Myzus persicae was assayed by its alive spores and fermentation filtrates. The results showed that Bb-2 was highly virulent at three consistencies, 1.1×10^7,1.1xl0^8, 1.1× 10^9 ind./mL. At high consistency 1.1×l0^9 ind./mL, the cumulative mortality of P. xylostella was 75.0%; and of M. persi- cae was 92.5% in 4 d. At low consistency, the cumulative mortality was 36.7%; and of M. persicae was 47.7%. The fermen- tation filtrates of strain Bb-2 were also with anti-pest active; and the virulence against M. persicae was stronger than P. xylostells.