Wingspan c. 12 mm.
The Syncopacma genus contains several species which are virtually impossible to distinguish except by genitalia dissection, and larseniella is one of these, easily confused with cinctella among others.
It is distributed in southern and eastern England, though earlier records from elsewhere are clouded by the fact that larseniella and cinctella were once considered a single species.
The larvae feed on greater bird's-foot trefoil (Lotus corniculatus), in a spinning between leaves. The adults fly during June and July and are attracted to light.