This is a fairly small species with a wingspan of 29–34 mm. It usually has pale grey forewings with darker markings towards the base, including the prominent black mark at the root of the wing which gives the species its common name. However this is a variable species and darker forms exist, including examples of industrial melanism which are prevalent in some towns and cities. The characteristic basal markings are not usually apparent on such individuals. The hindwings are pale or dark grey. The species flies at night in July and August  and is attracted to light and sugar, as well as various flowers.
- Chinery, Michael Collins Guide to the Insects of Britain and Western Europe 1986 (Reprinted 1991)
- Skinner, Bernard Colour Identification Guide to Moths of the British Isles 1984
|This Xyleninae article is a stub. You can help Wikipedia by expanding it.|