Last modified: March 2, 2021, 11:16 a.m.
This very rare and local species was recorded only once from the Belgian fauna: LX, Bastogne, 1955-08-21, where an empty chrysalid was found in the pupation place on Arnica montana, leg. E. Janmoulle. It was rediscovered in 2018 in an adjacent province (LG) and this time leaf mines were found (Wullaert S. 2019b).
Wingspan 11–13 mm.
Larvae can be found from autumn till May.
Starting with a light green, narrow, sometimes branching corridor, widening considerably later. Frass in an irregular, rather broad central line. In the thin mines in autumn, the frass is more concentrated against the side, making it look like a fly mine.
See also bladmineerders.be
The caterpillar frequently moves to another leaf. Pupation in a separate, lower-surface mine.
One long generation a year: from May till September.
Monophagous on Arnica montana.