Last modified: April 23, 2019, 12:44 p.m.
A declining species in Belgium. It used to be common in the 19th century. The reason of the decline might be the rarity of thistles.
Most observations are misidentifications of Agonopterix propinquella which has the forewing more arched.
See also bladmineerders.be
The species starts its life as a leafminer, but the caterpillars soon eat externally on the leaves of the foodplant. After a while they spin the leaflets together to form a tube in which they hide.
Pupation among detritus or in the earth at the base of the foodplant. The species hibernates as an adults. These adults are rarely seen during the day but they sometimes they come to light or can be beaten from the foliage.
One generation a year: from August, hibernating, till May of the next year.
Open terrain, waste ground, ruderal places, road sides.