The Miller Acronicta leporina
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.
It is generally distributed in woodlands and heathland over much of Britain, though commoner in the south, and 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 (Betula) but also on other deciduous trees.