Head dark brown to blackish; forewing ground colour golden brown; white pattern consisting of a rather short basal line, finely edged with brown scales, a tranversal line (formed by merging the first costal and dorsal striae), two (rarely three) costal and two dorsal striae, all except the most apical ones, finely edged with brownish scales. A conspicuous black dot in the apical area.

A white tentiform mine on the underside of a leaf. In later stages, the mine occupies the entire leaf area, on the underside many small longitudinal folds close to each other. At the end the leaf curles completely over the mine and the caterpillar has consumed all the parenchyma, colouring the mine completely white so that it resembles much a like white pod. The frass is concentrated in a corner of the mine.
See also gracillariidae.net and bladmineerders.be.

The final instar does not construct a real cocoon, just some loose threads, a.o. some kind of wall separating the pupal chamber from the frass.

Pupation inside the loose spinning in the mine. The species hibernates in the pupal stage. After emergence of the adult, the pupal skin protrudes from the mine.

The larva lives in on different species Melilotus, especially M. albus, and Medicago.

Road sides, ruderal places.