Wingspan 4-6 mm.
A relatively local species, but hard to find and probably overlooked in many places due to its upland bias. It has been found in England, Wales and Scotland, but is scarce in the south-east. In Ireland it has occurred in the south-west.
The foodplant is bilberry (Vaccinium), the larvae creating a mine which begins as a contorted gallery with a central line of frass, which then widens out and forms a false blotch. These can be found in July and from September to October.
The adult has dark purplish wings with a whitish fascia, orange head and white eyecaps.