It is known by the name "large rose sawfly" although the related species Arge ochropus is also known by this name.

Its most conspicuous feature is a large rounded yellow abdomen.

Larvae reach about 25 mm and are pale green with black dots and a yellow head.

Larvae appear in early summer and reach full size by the end of July.

Adults feed on nectar and pollen from Tanacetum vulgare and Heracleum sphondylium.