As we said before, the mayfly is a real icon of fly fishing, but it is also an incredibly valuable fly for your sport, and therefore worth packing plenty of them in your fly box for your fishing trip.
Biologically speaking, a mayfly undergoes three major stages in its typical life cycle: nymph, dun, and spinner. As far as fly fishing goes, five points in this life cycle require distinct artificial fly imitations. These are: nymph, emerger, cripple, dun, and spinner. A nymph imitation is fished exclusively in the subsurface as it is designed to imitate the mayfly during the major portion of its larval stage. An emerger is an artificial fly designed to imitate a mayfly during its emergence from a nymph to a winged adult dun. You should fish this one just beneath the water's surface or within the surface film. A cripple is similar to an emerger, but meant to closely imitate an emergent mayfly caught or trapped in the surface film by its own nymphal shuck, unable to hatch to an adult dun.
Both remaining artificial flies for fly fishing are the dun and spinner, which are designed and fished to imitate the the mayfly’s two separate and distinct winged life stages.
