Last modified: April 23, 2019, 12:44 p.m.
A common and widespread species in Belgium, present in all provinces.
Head brown; forewing ground colour brown, white pattern consisting of a straight basal line, a patch near the base at dorsum, four costal and three dorsal striae, all finely edged with dark brown scales; a dark brown patch in the apical area.
First instars whitish green, later on yellowish.
At first a short (max. 7 mm) blotch mine along the vein where the egg was oviposited, then growing into a long tentiform mine reaching from the main vein till the leaf margin. Some longitudinal folds close to each other. Frass is concentrated in a corner of the mine.
See also gracillariidae.net and bladmineerders.be.
A loose, white, silken cocoon at the opposite side of the mine than where the frass is concentrated. Pupa brown till blackish.
The egg is oviposited close to a vein on the underside of a leaf.
Pupation inside the silken cocoon. The species hibernates in the pupal stage, in the fallen leaf among leaf litter on the ground. The pupal skin is protruding through the mine after emergence of the adult.
Two generations a year: end of April till early June and July–August.
The species is monophagous on Fagus sylvatica.
Beech forests, parks, hedge rows aligned with Fagus.