Local in woodland and on heathland throughout much of the British Isles. In Hampshire and on the Isle of Wight fairly frequent amongst birch, especially on boggy heathland, but less common than formerly, occurring mainly in the south-west and north-east of the county. Wingspan 25-29 mm. Dark forms could be confused with Dingy Mocha C. pendularia
, which differs in more hooked apex of forewing and more pointed hindwing. Larva feeds on Downy and Silver Birch, over-wintering as a pupa.