Last modified: Aug. 13, 2019, 3:07 p.m.
A very rare species in Belgium, mostly found as a case on the foodplant.
This species uses a seed of the host plant as its case.
See also bladmineerders.be.
The eggs are laid on the flowers of the foodplant. The young caterpillar initially lives inside a seed of the host plant and, later on, uses an empty seed to move around and feed on the inside of other seeds.
So, this species is a seed-feeder. The caterpillar leaves its feeding place before wintertime and moves down to hibernate –mostly– in leaf litter. There, it pupates in springtime.
The moths fly from late May till the end of July.
The larvae of this species feed monophagously on Juncus gerardii.