Wingspan 6-8 mm.
This species occurs widely over most of the British Isles, and can be seen in the daytime between May and August. It rarely flies far, and can be found in shade and weak sunshine. It is a tiny species with a wingspan of around 6 or 7mm, being generally smaller than M. calthella.
The males are distinctive but the females are very similar to M. calthella though have the whole base of the forewing purple (M. calthella has a purple patch on the base of the costa, although it often has purple suffusion scattered over the whole forewing). The adults feed especially on pollen in hawthorn flowers but also on creeping buttercup and other species. The lower flowers of hawthorn are worth investigation.
The early stages are not well described, but the larvae are believed to feed at the bases of herbaceous plants.