Comparison on infection of Metarhizium anisopliae and Beauveria bassiana to Dendrolimus punctatus

Metarhizium anisopliae and Beauveria bassiana had been used to control Dendrolimus punctatus in lab .The lab test showed that there were not much differences in the toxicity to 3rd ～ 4th instar larvae of D . punctatus between M .anisopliae and B .bassiana at 25 ℃.The median lethal concentration of M .anisopliae was 6.38 108 sporesL-1 , and the median lethal time was 8.60 ～ 15.19 days for the concentration of 1.0 1011 ～ 1.0 107 sporesL-1 .The median lethal concentration of B .bassiana was 5.06 108 sporesL-1 , and the median lethal timewas 7.80 ～ 14.79 days for the concentration of 1.0 1011 ～ 1.0 107 sporesL-1 .The strain of M .anisopliae was more tolerant to high temperature and drought than B .bassiana .At high temperature or low humidity , the pathogenicity on D .punctatus was superior to that by B .bassiana .The lab test indicated that M . anisopliae was of greater value in controlling D .punctatus .