Head ochreous; forewing ground colour golden ochreous, white pattern consisting of a thin, long basal line, reaching the middle of the wing and finely edged with brown scales; four costal and four dorsal striae; the first dorsal stria just a match of some whitish scales, the second one much longer than the other ones and curved towards the apex; apical area shining purplish in fresh specimens; a small blackish dot in the apical area.

At first a rather small (max. 14 mm), semi-circular or oval tentiform mine on the underside of a leaf, between two secondary veins, preferably situated near the basis of the leaf. Later, the mine becomes longer; it has one longitudinal fold in the middle. The dark frass is concentrated in a longitudinal U-form inside the mine.
See also gracillariidae.net and bladmineerders.be.

Pupation within the mine without making a real cocoon, but away from the frass heap. Pupa dark brown.

The species hibernates in the pupal stage. However, in xerothermic regions, the larva of a third generation seems to hibernate in evergreen oak species, like Quercus ilex. Recently (2020) this has also been observed in Belgium.

The species has a preference for Quercus species, especially Q. robur, Q. petraea and Q. ilex, but it can develop also on a variety of other trees, like Carpinus betulus, Castanea sativa, Fagus sylvatica, and even Tilia cordata.