Last modified: Aug. 23, 2019, 1:44 p.m.
A common species throughout Belgium.
Greyish green with brownish head capsule.
First instars make a short serpentine mine on the upperside of a leaf that later broadens into a whitish blotch. Later instars contract the mine into an elongated tube. The free living instars roll a leaf margin downwards and fasten it with white silk.
See also gracillariidae.net and bladmineerders.be.
A transparant, yellow-shining cocoon.
Mines with caterpillars can be found from March till October, without a clear seasonal maximum. Pupation in a transparant, yellow-shining cocoon, most of the time at the underside of a leaf and at the leaf margin. The species hibernates in the adult stage. Moths take shelter in cracks of trees, with a preference for pine trees. They hide during daytime but come to light.
The adults fly in two generations a year: in June, and again from late August till April of the next year.
The larvae feed mainly on Alnus glutinosa, more rarely on Alnus incana.