Gray Drakes

These large, slender mayflies have nymphs of the swimming type, like Isonychiidae and Metretopodidae, and they generally inhabit slow water. See Siphlonurus for details -- it is the only genus of known importance to anglers.

The spinner falls of this elegant species can be quite important to anglers across the West. Recent revisions have synonymized the Midwestern species Heptagenia diabasia that may be of some local importance.

Ephemera guttulata's size, numbers, and hatching characteristics have made it a favorite of fly fishermen since the sport first came to our waters.

It is on par with the Midwest's Hexagenia limbata hatch for its ability to lure huge piscivorous (Piscivorous: Anything which eats primarily fish is a piscivore.) brown trout to eat insects at the surface once a year. The special charm of the Green Drake hatch is that it often takes place during pleasant Spring afternoons. It can be challenging because the large flies are easy for trout to inspect in the daylight and they feed very selectively, especially late in the hatch.

The Green Drakes are on the decline due to environmental degradation.

This is an important Western hatch.