Last modified: Jan. 28, 2020, 10:54 a.m.
A fairly common species in the northern part of Belgium, rather rare in the southern part.
The adult is ochreous with a lot of lighter longitudinal lines. The wingspan is 9–13 mm. The antennae are partly ringed.
The case resembles a seed-head very well and, when fully developed, measures circa 5 mm and has a mouth angle of 45°.
See also bladmineerders.be.
The eggs are oviposited on the flowers of the host plant. The larvae live on Artemisia vulgaris inside an eaten out inflorescence and are therefore very difficult to find. They move around from seed to seed leaving characteristic small perforations in the side of each one and are full-grown in September. The pupation takes place inside the case, often attached low down on a stem.
The adults are night-active from the evening till sunrise and come infrequently to light.
The adults fly in one generation during July and August.