Head brown, with some mixed white scales; forewing ground colour rather dark brown; white, sometimes yellowish white, pattern consisting of a basal line, not edged; a narrow, but mostly long patch at the dorsem near the base, sometimes connected to the first dorsal stria; four costal and three dorsal striae, the first dorsal stria is the longest.

A rather large, elongated tentiform mine on the underside of a leaf, frequently close to the leaf margin and the leaf basis. The mine is parallel to the leaf margin and has one or more central longitudinal folds. In later stages, the mine is stringly contorted and the leaf margin may be covering the entire mine. The black frass is concentrated in a corner of the mine.
See also gracillariidae.net and bladmineerders.be.

A tough light brown cocoon in which no frass is present.

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

The species lives on various, long-leaved species of Salix, with a preference for Salix alba, but it has also been recorded on other species, like: S. daphnoides, S. fragilis, S. incana, S. purpuralis and S. viminalis.