Last modified: Sept. 7, 2023, 2:28 p.m.
A not so common species throughout Belgium.
Wingspan: 35–45 mm.
Adults of Acronicta cuspis, Acronicta tridens and Acronicta psi cannot be safely distinguished from each other, except by reference to the genitalia. Although larvae of these species are quite different and are easy to identify as species.
From May till October.
The species hibernates, sometimes for several years as a pupa under bark or in bark crevices of the foodplant.
The adults come to light and sugar.
The adults fly in two generations a year: from mid-April till the beginning of September.