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Lateral view of a Female Hexagenia limbata (Ephemeridae) (Hex) Mayfly Dun from the Namekagon River in Wisconsin
Hex Mayflies
Hexagenia limbata

The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.

Lateral view of a Clostoeca disjuncta (Limnephilidae) (Northern Caddisfly) Caddisfly Larva from the Yakima River in Washington
This one was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
27" brown trout, my largest ever. It was the sub-dominant fish in its pool. After this, I hooked the bigger one, but I couldn't land it.
Troutnut is a project started in 2003 by salmonid ecologist Jason "Troutnut" Neuswanger to help anglers and fly tyers unabashedly embrace the entomological side of the sport. Learn more about Troutnut or support the project for an enhanced experience here.

Gray Drakes

Like most common names,"Gray Drake" can refer to more than one taxon. They're previewed below, along with 6 specimens. For more detail click through to the scientific names.

Mayfly Family Siphlonuridae

These are pretty much always called 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.
Female Siphlonurus quebecensis (Siphlonuridae) (Gray Drake) Mayfly Dun from unknown in Wisconsin
This one hatched in my house after I brought some nymphs home to photograph.
Lateral view of a Male Siphlonurus quebecensis (Siphlonuridae) (Gray Drake) Mayfly Spinner from the Namekagon River in Wisconsin
Siphlonurus mayfly nymph. These mayflies are known as strong swimmers that maneuver like minnows across the stream bottom

Artistic view of a Siphlonurus quebecensis (Siphlonuridae) (Gray Drake) Mayfly Nymph from the Delaware River in New York

Mayfly Species Heptagenia elegantula

These are very rarely called Gray Drakes.
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.

Mayfly Species Ephemera guttulata

These are very rarely called Gray Drakes.
Ephemera guttulata's size, numbers, and hatching characteristics have made it a favorite of fly fishermen since the sport first came to North American waters.

It is on par with the Midwest's Hexagenia limbata hatch for its ability to lure huge piscivorous 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 huge difference in appearance between green drake duns and the spinners, white-bodied "coffin flies," makes them a peculiarity among major hatches.

The Green Drakes are on the decline due to environmental degradation.
Artistic view of a Female Ephemera guttulata (Ephemeridae) (Green Drake) Mayfly Dun from the West Branch of the Delaware River in New York
For years after I started this website, I was eagerly hoping to find a green drake to add to the collection, but I was never in the right part of the world at the right time. It finally happened on June 1st, 2007.
Lateral view of a Male Ephemera guttulata (Ephemeridae) (Green Drake) Mayfly Spinner from Penn's Creek in Pennsylvania
This spinner was the only member of its species I saw all night during an incredibly thick and tricky mixed hatch on Penn's Creek a few days before the real start of its famous green drake hatch.

Mayfly Species Ecdyonurus simplicioides

These are very rarely called Gray Drakes.
This is an important Western hatch.
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