This species is sexually dimorphic. Females give the species it's name, as it has four brown spots on it's forewings, though usually only three spots can be seen, as one is covered by it's wing. Forewing is yellow apart from spots. Males have a yellow body, and grey forewings. The male of this species has a length of about 20mm, while the female has a length of about 24mm.In Britain, this species is Nationally Scarce A, as well as an immigrant.
This species flies from July-September.