[2] The habitat consists of heathland, chalky downland, fenland, moorland and upland areas.

is also a dark but unicolorous form, occurring in Scotland and the North of England; - sylvatica Bell is a grey, obscurely marked, insect without brownish tinge, from Corsica; - septentrionalis Hoffm.

is a small black form from Finland, the Baltic provinces and the Ural Mts., of which moesta Stgr.

from Central Asia is paler, more violet brown, with the markings clearly expressed; anilis Bsd.

[4] Larva grey green, suffused dorsally with reddish, with many small fine streaks; dorsal and subdorsal lines dark; spiracular line pale, whitish or yellowish; head greenish ochreous.