Last modified: March 6, 2021, 10:34 a.m.
A fairly common species in the northern part of Belgium, elsewhere not so common.
First instars mine in the pith of a leaf-sheath? The older larva first lives in the flower-spike or enters the thin stems, at last, in springtime, it lives in the seeds, causing them to bend down so that they hang out in large, conspicuous masses. The larvae hibernate, often gregariously, inside the flower-spike.
Pupation takes place in the seed heads during springtime.
The adults fly around the food plant at dusk and later come to light.
One generation a year: from mid June till the end of August.
Banks of lakes and rivers, freshwater ponds.