Wingspan 13-17 mm.
An attractive species, which when fresh, shows a series of bluish metallic and tawny markings, with a rosy flush to the whitish ground colour.
Widely distributed throughout Britain, it is commonest in the south, becoming gradually scarcer further north.
The moths fly in June and July, and are partially diurnal, the males in particular flying at sunrise and in the afternoon.
The larvae feed internally in the acorns of oak (Quercus) and the nuts of sweet chestnut (Castanea sativa).