[Biological characteristics of Metarhizium anisopliae var. major and its virulence to white grubs].

With Beauveria brongniartii and Metarhizium anisopliae var. anisopliae as the reference, this paper studied the biological characteristics and invading ability of Metarhizium anisopliae var. major, a new variety separated from white grubs. The results showed that the optimal culture condition of M. anisopliae var. major was similar with that of other entomopathogenic species, and the optimal temperature was 25 degrees C. Among the three test media, PPDA was the most appropriate one, followed by SDAY and Czapek. M. anisopliae var. major had a stronger virulence than B. brongniartii at lower temperature, with an accumulative mortality of white grubs being 88.23% and 76.47%, respectively, after treated with soil and through spraying, suggesting that M. anisopliae var. major had a good prospect to widely apply in field.