Nationally scarce (Nb) on cliffs along the northern coasts of Britain and Ireland (ssp. colquhounana) and in mountains in northern regions (ssp. penziana). Unlikely to be recorded in Hampshire or on the Isle of Wight. Wingspan 21-27 mm. Although extremely variable, the large size and elongate forewings readily distinguish this species from related species. Larva feeds on roots of Thrift and Sea Plantain (ssp. colquhounana) and Sheep's-fescue (ssp. penziana), living within a silken tube or tent.