Last modified: Feb. 22, 2021, 1:57 p.m.
See also bladmineerders.be
The adults fly from April till the end of May.
The young larva makes a circular blotch mine in the leaves of Fagus sylvatica, sometimes on Quercus or Tilia. Then it falls to the ground in a case cut from the blotch. This case is subsequently replaced by bigger ones as the larva grows. The caterpillar then eats dead leaves. It hibernates fully-fed in that case. Pupation in the case amongst leaf-litter.
The moths are active during the day.