A characteristic coppery-golden Y-shaped marking is present in the middle of the wings.

[1] They fly at night and on sunny afternoons and mainly feed on the nectar of tansy (Tanacetum vulgare).

[6] The larvae feed on birch (Betula species) and alder (Alnus glutinosa).

[3] They overwinter in a shoot or hard male catkin of the host plants.

In late March or April, larvae congregate and pupate in a cocoon under the bark.