Wingspan 4.5-6 mm.
The commonest of a complex of similar species which have oak (Quercus) as the foodplant.
The larvae feed in June and July and between September and November, forming a long gallery, initially with narrow black frass, later becoming more dispersed. The egg is laid on the upperside of the leaf.
The adult moths are similar to several other species in the group, having uniform dark brownish wings with a bronzy sheen. They are on the wing from May to June and in July and August.