A not so common species in Belgium, but probably much more widespread.

The larva makes a leaf mine on the upperside of Populus tremula, occasionally also on P. alba and P. canescens. It starts as a narrow, contorted gallery usually beside a rib and later it widens, often forming a false blotch by merged 'S' turns, or even a true blotch. 

The adults fly in one protracted generation during June and July.