Local in damp, shady woodland throughout much of England and Wales, more numerous in the west. Widespread and sometimes locally common on the Isle of Wight, but rarely recorded on mainland Hampshire. Wingspan 9-12 mm. Day-flying. More frequently recorded in the larval stage, when the mines and cases are occasionally numerous; the imago resembles
P. filicivora with violet tinge but lacks white tornal spot. Larva mines fronds of Hart's-tongue, subsequently living within a movable case.