Abstract
In Nara Prefecture, spring occurrence of bud damage by the strawberry blossom weevil, Anthonomus bisignifer Schenkling, on forced strawberry and wild host plants were investigated. Overwintering adults emerged from hibernation in late March to early April and began to injure flower buds of Rubus hirsutus Thunb. About 2 weeks later, adults injured strawberry flower buds in a greenhouse from early to mid-April. Thereafter until late April, adults began to injure flower buds of Rosa multiflora Thunb. Overwintering adults used different wild host plants depending on the flower budding period. Larval occurrence was earlier on the greenhouse strawberry than on R. hirsutus growing outside of the greenhouse. The start of first generation adults' emergence from the pupae was estimated as about late April to early May. The density of damaged buds on the strawberry differed greatly among years for unknown reasons. Commercial concentrations of thiacloprid, spinosad, and malathion were effective against adults in in vitro experiments.
