Last modified: Feb. 23, 2022, 6:54 p.m.
Used to be a rather common species in Belgium, but nowadays rare and only in the southern part of the country.
Wingspan 17–22 mm, forewings unicolourous bronze, sometimes with golden hue. A brownish-grey discal spot. Antennae in the male with some black scales at the base. Head of male ochreous yellow, eyes enlarged, in the female yellow head, eyes normal.
Whitish transparent skin. Head and all three thoracic plates shining black.
The case of the young larva is made of a seed capsule of Knautia of which it eats the contents. Later on, plant particles are added till the case becomes up to 12 mm, it is more or less oval.
The larva lives at first on the seeds of the food plant, then on the lower leaves and possibly on leaf litter, from a flat bivalved case on the ground. Pupation in the case. The moths are active during the day. They like to rest on the flowers of the larval foodplant.
The adults fly from the end of June till early August, sometimes as late as mid September.
Meadows, roadsides, forest edges with a lot of flowers, as long as the larval foodplant grows there as well. The species has been observed in extensively used landscapes.