Common in oak woodland throughout much of England and Wales, and parts of Scotland. In Hampshire and on the Isle of Wight still locally common in the New Forest and the north-east, but has declined markedly from the middle of the 20th Century. Wingspan 39-44 mm. The main confusion species is Lunar Marbled Brown D. ruficornis, which see. Larva feeds on Oak, over-wintering as a pupa.
The abundance in each month is indicated as follows:
No records Very occasional Irregular Uncommon Off-peak, but not unusual Off-peak, but not unusual Main flight time