Sweet Chestnut Gall

Dryocosmus kuriphilus

Ian Gilbert discovered galls on sweet chestnut where he lives in Scotland. The galls are believed to be caused by a small, stingless Asian wasp that lays eggs leading to abnormalities in buds, leaves, and petioles. Research indicates that there is only one type of gall known to develop on sweet chestnut in Britain, which supports the likelihood of this identification being accurate. The Asian wasp's galls usually create a bulge at the base, but the absence of such bulges in the picture may suggest that this is an early stage of development. These galls can inflict significant damage, prompting a survey of sweet chestnut trees located on Cabin Hill in Hainault Forest. Fortunately, no galls were found here.