Wingspan 14-15 mm.
An adventive colonist, first discovered in Britain in 1943 in south-east Kent. Since then it has become widely established over much of England and Wales.
The larvae feed inside the seeds of sycamore (Acer pseudoplatanus), and their presence is sometimes betrayed by small exit holes in the seeds themselves.
The adult moths are on the wing in July and August, from late afternoon onwards, and are most often encountered at light.