Last modified: Feb. 27, 2021, 4:06 p.m.
Only known from old records: no new records in Belgium, probably extinct.
Native
Head white; forewing ground colour ochreous brown to brown, white pattern consisting of white basal line, four costal and two dorsal white striae and a small white patch near the basis of the inner margin.
A large tentiform mine on the underside of a leaf, with many small longitudinal folds. The mine extends a large area from the main vein till the leaf margin. The sides of the mine are whitish because the parenchyma is consumed, leaving a green patch in the center. In rare cases, more than one mine occur on one leaf, but then the leaf is contorted. The dark frass is concentrated in one corner of the mine.
See also gracillariidae.net and bladmineerders.be.
Instead of a real cocoon, just some spun threads.
The full-grown last instar spins a loose web of silken threads inside the mine and pupates within them. It is not clear yet whether the larva or the pupa hibernates.
Two generations a year: May–June and August.
This species lives mainly on Quercus robur, though also Quercus pubescens has been recorded as a host.