Wingspan c.19 mm.
This highly distinctive species once used to occur in England, where a colony was present in Kent until around 1975, since which it has not been recorded. There are also old records from Essex and Co. Durham dating back to the 19th century. It now appears to be restricted to the Burren area of County Clare in Ireland.
The moths fly in June and July around their favoured habitat of dry, chalky grassland.
The larval foodplants are common milkwort (Polygala vulgaris) and chalk milkwort (P. calcarea), the larvae feeding in a slight spinning. The pupa hangs openly from a silken pad on the foodplant.