It is an abundant and familiar species across its huge range which covers the whole Palearctic region from Ireland to Japan and including the Near East and North Africa.

The wings are greyish white with three irregular black blotches along the costa of the forewing, the largest in the middle.

In the typical form the ground colour is dirty whitish and the median band is almost or altogether obsolete in its posterior half.

The species has an exceptionally long flying season spanning two or three broods, and the adults can be seen any time from April to October in the British Isles.

The larva is grey or green with pale, diamond-shaped markings along the back.