Oriental chestnut gall wasp

The oriental chestnut gall wasp (OCGW) (Dryocosmus kuriphilus) is a notifiable pest of sweet chestnut trees and other trees in the chestnut (Castanea) genus. The adult wasp is 2.5-3 mm in length and the female causes damage to chestnut trees by laying eggs in the buds of twigs. Galls form on the buds, leaves, and petioles as the larvae feeds, this can weaken the tree leaving it vulnerable to other diseases.