Last modified: Feb. 11, 2022, 11:01 a.m.
A fairly common species in Belgium, especially in Flanders at the coastal area. In the southern part of the country it is very rare.
Oval tentiform mine on the underside of a leaf between two secondary veins, showing no longitudinal folds. On the underside the mine is hardly visible as is has almost the same colour as the rest of the leaf, on the upperside, however, the mine is visible as a lighter green or yellowish blotch than the rest of the leaf. The sides of the mine are lighter and a green spot remains in the center, but it grows gradually smaller when the caterpillar consumes the leaf tissue. The frass is contained in a corner of the mine.
See also gracillariidae.net and bladmineerders.be.
A very thin cocoon. The pupa is dark brown, almost blackish.
The eggs are deposited on the underside of a leaf, and there can be several mines on the same leaf. Pupation inside the mine. The adults rest during the day on tree trunks and in the foliage. They become active at dusk and come to light.
Two generations a year: May–June and August.