Midges, compared to mayflies, caddisflies and stone flies are the most misunderstood, yet in numbers and distribution these mosquito like flies are the single most important aquatic insect trout eat.

Midges like caddis flies have four stages of metamorphosis. Egg, larvae, pupa, and adult. How ever the fisherman must be prepared with 5 basic patterns to successfully imitate the stage being eaten by the trout at the time.
Midge larvae, underwater pupa, floating pupa, still born adult midge hatching, and adult on the surface ready to fly.

This fly is supposed to look like a "cluster" (or two at least) of midges on the surface.

 Pro tied on Dai-Riki dry fly hooks in size 18