The
wingspan is 32–37 mm. The length of the forewings is 16–20 mm. Forewing red brown much mottled with darker; median shade prominently darker; the wavy whitish submarginal line forming a conspicuous white triangle on submedian fold; upper stigmata pale grey; claviform small, black-edged; hindwing dull fuscous, the basal half paler, with dark veins and lunule;- in
splendens Stph. the brown tint is predominant and the markings are obscured; — in
rufa Tutt, with the markings also obscured, the red tint overpowers the brown; while
pallens Stgr. is pale yellowish grey brown, with the markings indistinct; this form is found in W.
Turkestan and also in Iceland; –
scotica Tutt is a dark purplish grey form from Scotland and England, Finland, Lapland, and E. Siberia. ==Biology==