Dryocosmus kuriphilus

Dryocosmus kuriphilus is a species of gall wasp known by the common names chestnut gall wasp, Oriental chestnut gall wasp, and Asian chestnut gall wasp. It is native to China and it is known in many other parts of the world, particularly the Northern Hemisphere, as an introduced species and an invasive horticultural pest. It attacks many species of chestnut (genus Castanea), including most cultivated varieties. It is considered the world's worst pest of chestnuts.