Barred Chestnut Diarsia dahlii
Wingspan 32-42 mm.
Widely distributed but local, in Scotland, the northern half of England and Wales, it is scarce elsewhere except in parts of south-east England.
The females are usually darker than the males, some of the darker forms resembling Purple Clay (D. brunnea).
It inhabits woodland and moorland, where the caterpillars live on birch (Betula) and bilberry (Vaccinium myrtillus).