Toxicity determination of different Beauveria bassiana strains to Loxostege sticticalis L.

The pathogenicities of 16 Beauveria bassiana strains isolated from Inner Mongolia to Loxostege sticticalis L.larvae was tested in the lab.The results indicated that the pathogenicities of 16 strains were different.And S3 strain with high effective mortality(cadaver rate) was selected from the toxicity determination experiment,which showed relatively str-ong toxicity.The cumulative mortality of L.sticticalis larvae inoculated by same strain increased with the increase of spore concentration.Death quantity of L.sticticalis larvae decreased day by day,which showed the cumulative mortality of L.sticticalis larvae increased after treatment.And LT50 of the strain decreased with the concentration increased.