There are three species of chaser to be found in Norfolk and all have a dark triangular patch at the base of their hind wings, a feature that distinguishes them from skimmers. Whilst male scarce chasers and male broad-bodied chasers both have blue abdomens, the four-spotted chaser does not. Instead in this species the males and females are essentially similar, being predominately brown in colour with yellow spots along both sides of the abdomen. The key feature of four-spotted chasers is the extra dark spot to be found half-way along the leading edge of each wing. It is these four extra spots that give rise to the common name of this species. There is a second colour form, known as praenubila, where the dark markings on the wings are more extensive. In some individuals the dark mark near the wingtip can become a band that extends right across the width of the wing.