Last modified: April 7, 2021, 5:15 p.m.
A rather common species in most areas of Belgium.
The larva lives in the stem of the food plant, usually in the axils of a bunch of flower stalks, making a gall from which frass exudes and causing the flowers to abort. Sometimes several galls are observed on one stem. The larva of the second generation hibernates in the stem.
Pupation inside the stem in a short, upward-sloping mine with a partial plug in the entrance.
The adults are active at dusk and come readily to light. Once, more than 10 specimens were observed at Niel (AN) in the beginning of April.
Two generations a year: April–June, and again in July–September.
Monophagous on Eupatorium cannabinum.
Humid habitats: along brooks, ponds, lakes and rivers.