Last modified: June 30, 2021, 2:49 p.m.
A very rare and very local species in Belgium, only known from some localities in the southern provinces.
Adults are not often seen, but larvae in their communal webs are frequently found.
The eggs are deposited in a group at a terminal shoot of the foodplant and covered with a spinning in which the hairs of the abdominal last segment of the female are used. The caterpillars live gregariously in a tough, white, silken web from where the feed on the adjacent leaves. The species hibernates in the pupal stages and sometimes the pupa hibernates several times.
The adults are active at night and come to light.
One generation a year: from late February till early April.
Xerothermic slopes, road sides, meadows lined with Prunus spinosa and Crataegus.