Wingspan 7-8 mm.
A tiny whitish moth with some yellowish suffusion and a distinct black spot near the wing apex, it is fairly common in most of England, becoming scarcer further north.
The adults fly in July and from September onwards, overwintering sometimes in haystacks.
The larva creates a very distinctive feeding pattern on the leaves of poplar (Populus). The mine is a long, winding shiny 'snail-trail' caused by the slight raising of the epidermis. There is no visible frass, and the larva pupates at the edge of a leaf, causing it to curl.