The regular form of 4 Spotted Chaser dragonfly has, as its name suggests, 4 wing spots, in the middle of the leading edge of each wing. The marks at the outer leading edge of each wing ate known as Stigmata and almost all dragonflies have them. In this Praenubila form however, the spots and Stigmata are enlarged into smudges of dark colour. Its not uncommon, just a variant that is seen from time to time.