Research on optimum time period of Beauveria bassiana YS03 against Lissorhoptrus oryzophilus

This paper determined the effects of Beauveria bassiana YS03 on feeding，oviposition and pathogenicity of rice water weevil（Lissorhoptrus oryzophilus） in different periods，investigated the seedling time and spawning peak of rice water weevil adults，to study the optimum time of YS03 to prevent and control rice water weevil. The results showed that in different periods，the effects of YS03 on feeding and oviposition of rice water weevil were not significantly different，and YS03 had good insecticidal effect on rice water weevil adults after 10 days. Field survey indicated that rice water weevils were fast migrating to rice seeding after 3 days，the adult peak appeared in 7 days，and spawning peak appeared in 10 days. 7 days after transplanting，the adult numbers and fecundity of rice water weevil were significantly higher than those in other time. So 3-7 days after rice seedlings planting，spraying B. bassiana YS03 had excellent control effect.