Last modified: March 25, 2021, 12:16 p.m.
A very rare and local species in Belgium.
The final straw-colored case is about 11 mm long.
The mouth angle is. 25°.
See also bladmineerders.be.
The eggs are deposited on a flower of mainly Thymus.
The larva begins its life by eating out the ripe fruit of a floret of Thymus serpyllum. Then it hibernates.
After hibernation the larva switches to grasses, making a new case made out of a mined grass leaf. Larvae from the end of August till the end of May.
The adults are mostly day-active.
The adults fly in July till in August.