Wingspan 10-13 mm.
The latest of the Betula feeding Eriocraniidae, with larvae feeding from mid-June into August. Like related species, the larva mines a leaf of the foodplant, starting with a narrow gallery, leading to a blotch filled with filament-like threads of frass.
The adult moths are very attractive when viewed closely, having a metallic golden ground colour, intensely speckled with purple and blue. There is also a golden tornal spot. They fly from late April into May and can be netted during the day flying around the foodplant, birch (Betula).
The species is locally but well distributed throughout Britain.
See also: Leafmine (British Leaf Mining Fauna)