Local in deciduous, especially oak, woodland, and parkland throughout much of England and Wales, where more widely distributed in the south. In Hampshire common in oak and sweet chestnut woods throughout, but perhaps under-recorded on the Isle of Wight. Wingspan 13-17 mm. The large, subfalcate medio-dorsal blotch, the presence of two or three sometimes contiguous black spots above the pre-tornal marking and the usually extensive series of black dashes in the ocellus are characteristic [Bradley]. Larva feeds within fruit of Sweet Chestnut and Oak, forming spongy galls, and over-wintering in a cocoon.