Wingspan is about 10 –14 mm. Forewing ground colour is yellow with a dark brown pattern consisting of two patches, one before and the other distally of the wing center, both patches connected by a thin dark brown line.

Short, stout and spindle-shaped, purplish brown; head capsule and prothoracic plate dark brown.

A very flimsy cocoon on the ground, some earth particles are used to camouflage it.

The egg is oviposited near or on the fruit of the foodplant. Feeding evidence is hardly noticed, just a small hole and some frass protruding from the fruit. Full-grown larvae leave the fruit and drop to the ground in September.
Pupation between leaf litter on the ground. The species hibernates in the pupal stage.
Adults rest during the day in the foliage or on tree trunks and sometimes come to light. Typical resting position on its fore and mid legs, but with the hind legs turned slightly forwards and upwards. These hind legs possess strong spurs and are coloured in the same yellow and dark brown as the wings, possibly aiming to mimic a wasp-like hymenopteran or a thorn-like structure for defense.

The larva lives in the fruits of Alnus glutinosa.

Rather moist environments wherever Alnus grows.