Head ochreous to brown; forewing ground color golden brown, a white pattern consisting of two transverse bands, two costal and one dorsal striae; a small dark spot in the apical area; basal line absent.

Whitish to yellowish with a light brown head capsule.

A tentiform mine on the underside of a leaf, situated between two secondary veins and most of the time not close to the main vein. Underside without clear longitudinal fold, but with several small wrinkles. The black frass is concentrated in a corner of the mine.
See also gracillariidae.net and bladmineerders.be.

A tough, white cocoon, attached to the roof of the mine, without any frass.

The eggs are oviposited singly on the underside of a leaf, but many eggs can occur on one leaf.
The species hibernates in the pupal stage in the cocoon among fallen leaves between leaf litter on the ground.
After the emergence of the adult the pupal skin protrudes from the mine.
Adults rest during the day on tree trunks, they become active at dusk and come to light.

The larva lives mainly on Alnus glutinosa, but it also occurs not infrequently on Alnus incana.

River sides, open places in forests.