Vulnerable (proposed as a future Red Data Book species) on coastal limestone cliffs, sand-dunes and disused chalk quarries in south-western England and the Thames Estuary, recorded in Cornwall, Devon, Essex and Kent from 1983 onwards. Not recorded in Hampshire or on the Isle of Wight to date. Wingspan 10-12 mm. Extremely similar to
B. basaltinella, which see. Larva feeds on various mosses, living within a silken tube or tent.