Discovery of insect parasitism and subsequent development of parasitoid research in Japan

In Japan, early research on insect parasitism, i.e., from 1850 onwards, had a profound effect of sericulture. Insect parasitism in Japan was recognized in 1856, when S. Iimuro first described parasitism of silkworm larvae by the tachinid Blepharipa sericariae. C. Sasaki published a full report on the life history of this parasitic fly in 1887, showing that the female fly laid microtype eggs on mulberry foliage, that these eggs were ingested by the silkworm larva as it fed, and that they hatched in the host gut to parasitize it. C. Sasaki shared credit for this epoch-making discovery with his father, N. Sasaki, who pioneered research on parasitism in Japan. Much work on ecology, behavior, physiology, and control of this pest fly was done from the time of discovery until the 1950s, when sericulture began to decline in Japan. Subsequent contributions to parasitoid research included Utida’s [Ecology 38 (1957) 442] outstanding work on population interactions in laboratory host-parasitoid systems. More recently, most parasitoid research has dealt with ecology, especially behavioral ecology of parasitoids and the use of parasitoids in biological control of insect pests. However, the taxonomy of the parasitoid fauna is not well developed in Japan, constituting a major obstacle to continued ecological research.