Wingspan 17-26 mm.
One of the more distinctive Epiblema species, with its diagnostic angular whitish marking on a dark brown ground colour, although the shape and colour of this mark does vary.
Fairly common in the south and west of Britain, becoming rarer in the north and east.
The larvae feed on the roots and lower stem of mugwort (Artemesia vulgaris).
The adults fly from late afternoon into the evening, and come to light at night.