Oriental Chestnut Gall Wasp (OCGW)
Symptoms of the Oriental Chestnut Gall Wasp:
Growths are formed by the larvae of the Oriental Chestnut Gall Wasp which tend to be on younger leaves
The growths are between 5-20mm in diameter
Distortion and deformity of leaves which turn brown
The wasp laying eggs
About the Oriental Chestnut Gall Wasp:
The wasp was first seen in the UK in 2015, a second site was later confirmed in a single street in Hertfordshire, England. The oriental wasp is an insect of Asian origin which affects sweet chestnut trees. The wasp is a pest of sweet chestnut trees due to the activity by its larvae which then causes galls to form on the buds, leaves and leaf stalks. The galls start out green when they begin to develop about March, they then turn red by June. They start to dry out and turn brown over the summer, when the adult wasps emerge from them, they can cause the leaves to drop early.