Parasitoids of Dryocosmus kuriphilus (Hymenoptera: Cynipidae) in South Korea with Particular Reference to Ecologically Different Types of Torymus (Syntomaspis) sinensis (Hymenoptera: Torymidae)

Abstract

Torymus (Syntomaspis) sinensis was recently recorded in South Korea as a native parasitoid of the chestnut gall wasp, Dryocosmus kuriphilus, and proved differ from a Chinese population, which was imported into Japan and has become established, in the seasonal prevalence of adult emergence. Findings of the present study suggest that the parasitoid which has been recorded in South Korea as “Torymus beneficus” is probably not beneficus but, in fact, T (S.) sinensis, and that the Korean populations of T (S.) sinensis might possibly consist of two types differing in the period of adult emergence. Eight species of parasitoids emerged from withered galls collected in Korea, among which T. (.S.) sinensis was dominant at all investigation sites. Seven other parasitoids, Torymus (Torymus) geranii, Ormyrus punctiger, Eurytoma setigera, E. brunniventris, Sycophila variegata, Eupelmus urozonus and Eupelmus sp. of the first generation, were considered to parasitize the chestnut gall wasp as primary parasitoids and those of the following generations act as hyperparasitoids. © 1995, JAPANESE SOCIETY OF APPLIED ENTOMOLOGY AND ZOOLOGY. All rights reserved.