Black arches

The eggs are oval, light brown or light red. Larvae are whitish grey to blackish, with grey hairs, red and blue warts, and a dark longitudinal dorsal line which is interrupted or broadened into spots in places. Pupa is golden glossy red-brown or dark brown, with reddish hairs dorsally and rather long anal point.

White forewing with black basal spots and four sharply angulate black transverse lines, the second of which is the broadest; hindwing greyish white and grey. Abdomen light rosepink. The species varies strongly and has received the following aberrational names, nigra Fr.: The two central bands are confluent at the costal and posterior margins, forming black spots, or the whole median area is dark, the red of the abdomen usually weaker, eremita G.: Forewing and abdomen smoke-brown or blackish grey, the former with black markings, atra Linst.: Forewing uniformly black, without markings, hindwing greyish brown, abdomen black, lutea Anel is a light form in which the central bands are interrupted; the red colour of the abdomen is equally deep almost to the thorax, flavoabdominalis Schultz has the abdomen yellow instead of red; subfusca Schultz female is distinguished by everything which is black in true monacha being yellowish brown, and the abdomen being also yellowish brown instead of red; in obsoleta Schultz the dark transverse bands in the median area of the forewing are absent, while they remain in the basal and outer-marginal areas. All these names were given to European specimens.