Oriental Chestnut Gall Wasp, Dryocosmus Kuriphilus Yasumatsu

The oriental chestnut gall wasp, Dryocosmus kuriphilus Yasumatsu, threatens the chestnut industry in southeastern United States. The wasps form galls in American chestnut, Castanea dentata (Marsh.) Bork., Chinese chestnut, C. mollissima Bl., and Japanese chestnut, C. crenata Sieb. & Zucc. The galls suppress shoot elongation and reduce fruiting. Trees with severe infestations lose their vigor and often die. Commercial growers may expect yield reductions of 50-70%. Severe infestations may result in the decline and death of chestnut trees. The oriental chestnut gall wasp is a severe pest to the chestnut industry in Japan and Korea (Payne 1978).