Pupal Mortality of the Oriental Tea Tortrix, Homona magnanima DIAKONOFF (Lepidoptera

The mortality of Homona magnanima pupae was investigated at the tea gardens in Mizuho and Fuchu, Tokyo from 1989 to 1990. Two species of chalcids, Brachymeria lasus and B. excarinata, 6 species of ichneumonids, Itoplectis alternans spectabilis, Coccygomimus disparis, C. luctuosus, C. nipponicus, Agrothereutes lanceolatus, and Scambus vulgaris, 2 species of tachinids, Zenillia dolosa and Bessa parallela, and an entomopathogenic fungus, Erynia radicans were reared from the pupae collected from both sites. The ichneumonid, Phaeogenes sp., a cytoplasmic polyhedrosis virus, and an entomopox virus were recorded only at Mizuho. The mortalities due to these factors changed with time and locality. The highest mortalities caused by parasitic wasps, tachinids. E. radicans, and viruses were 68.8%, 17.9%, 15.8%, and 4.0%, respectively. The species structure of the parasitoid complex differed among host generations: I. alternans spectabilis and C. disparis were the major species in the overwintering generation, while B. lasus and B. excarinata were dominant from the 1st to 3rd generations.