Wingspan 35-45 mm. Another variable species, the whitest forms occurring in parts of Scotland and the darker ones in northern England and the Midlands, in industrial areas. Typically, the species is pale greyish, a form known as f. grisea.

Woodlands, other well wooded areas and heathland

Flies from June to August

The highly distinctive caterpillar is pale green and is covered with extremely long whitish hairs, giving the whole larva a feather-like appearance. It feeds mainly on Birch but also on other deciduous trees.

It is fairly frequent and distributed over much of Britain though commoner in the south. In a recent survey to determine the status of all macro moths in Britain this species was classified as common.

Fairly common in Leicestershire and Rutland. L&R Moth Group status = A (common and resident)