Wingspan 4-5 mm.
A common species throughout the British Isles, which has a single generation. The adults are on the wing in May and June, and subsequent larvae feeding from June till August.
The larvae mine the leaves of hawthorn (Crataegus), creating a gallery which begins narrowly with black linear frass. The mine then widens, and the frass is laid in distinct arcs, finally becoming irregular and central near the end.
The adults are narrow-winged with bronzy forewings which have a broad silvery fascia, and are purplish-tinged outside this.