Abstract
Beauveria bassiana strain HF338 had the highest pathogenicity among 77 isolates to larvae of the chestnut weevil, Curculio sikkimensis (Heller) (Coleoptera: Curculionidae). Its pathogenicity at 25°C was similar to that of Metarhizium anisopliae strain HF293. Its pathogenicity at 15°C remained high, whereas that of M. anisopliae HF293 was greatly reduced. Its pathogenicity to chestnut weevil adults and nut fruit moth, Cydia kurokoi (Amsel) (Lepidoptera: Tortricidae), was also higher than those of M. anisopliae HF293. In field tests, the survival rate of chestnut weevil larvae decreased to 2.9% when B. bassiana HF338 was applied at 1×1011 conidia/pot. The high pathogenicity of B. bassiana HF338 makes the strain a potential microbial agent for the control of chestnut pests.
