Life History of Curculio Camelliae RoelOfs (Coleoptera: Curculionidae) and its Susceptibility to Metarhizium anisopliae and Beauveria tenella

Abstract

Curculio camelliae attacking camellia fruit in Izu district was investigated ecologically. Adults were observed in camellia from late May to late July. They fed on the gelatinous contents of seeds by inserting a long rostrum through a shell. Females oviposited into seeds in June. Hatched larvae grew up till the 4th instar in the seed for a month. In late July, mature larvae started abandoning the fruit, by boring an exit hole, and dropped on the ground under the tree. Immediately after, they went underground and overwintered there. High percentages of bored seeds were observed especially in the Eastern and Southern area of Izu Peninsula. The susceptibility of weevil larvae to two entomogenous fungi, Metarhizium anisopliae and Beauveria tenella, was estimated by two inoculation techniques, i. e., dipping in spore suspensions or maintenance in spore-infested soil. Larvae showed a high susceptibility to infection with both fungi, and there was no significant difference in the effect between natural and autoclaved soil. It is concluded that M. anisopliae and B. tenella could become potential microbial control agents for the soil-inhabiting larvae of C. camelliae. © 1982, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.