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Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

Mayfly Species Ephemera guttulata (Green Drake)

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 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.

Where & when

Time of year : Late May through late June

This hatch begins in Pennsylvania in late May and moves into the Catskills through early June. Mid to late June sees Green Drake action in the Adirondacks and other northern New England rivers.

Hatching behavior

Time of day : Noticeable emergence all day long, peaking in late evening, sometimes all compressed to dusk

Green drakes nymphs swim to the surface and emerge from their shucks very quickly. Ernest Schwiebert describes the difficulty this gave him in trying to catch a nymph:

"They emerged from their shucks with such speed that I was usually left with an empty shuck and the subimago with which I was already familiar. I began to think that catching the trout was easier than catching the nymphs that the trout were catching."

This haste makes emerger patterns unimportant, but luckily the duns take a long time to get off the water. They flutter around and make several awkward attempts, drawing explosive strikes from trout. Hackled imitations that can be twitched to match this behavior are popular.

Knopp and Cormier write that the best hatches happen during "sustained periods of warm weather."

Spinner behavior

Time of day: Dusk

These spinner falls can be extremely intense and they are the most anticipated part of the Green Drake action. They return to mate about three days after emerging as duns.

Just like Ephemera simulans, Ephemera guttulata spinners in the air do not always mean spinners on the water. Subtle shifts in weather may push promising spinner clouds of both species back into the trees for the night. This usually happens when they are still gathering at treetop level. Once the swarms descend and you find yourself surrounded by them, they are almost sure to fall on the water, and good fishing will follow unless the trout have just filled up on nymphs and duns during the hatch.

The spinners are known as "Coffin Flies" and they are black and white. They look like a completely different species than the greenish yellow duns.

Nymph biology

Substrate: Silt and detritus, sometimes fine gravel and sand

Environmental tolerance: Low tolerance for pollution and warm water

Most writers say Green Drakes tend more toward the silty habitats of Hexagenia than do Ephemera simulans and Ephemera varia. It does not, however, require the same vast beds of silt for a good hatch, and the nymphs may do well in small patches of silt which pile up in the quiet spots in pocket water and rocky pools. They are reported to inhabit sand and fine gravel in sufficiently fertile streams. In Ted Fauceglia's recent book Mayflies he says they are actually more abundant in this typical Ephemera habitat.

Ephemera guttulata Fly Fishing Tips

The mature nymphs of this species are darker than the yellow bodies of other Ephemera nymphs. Ernest Schwiebert described them as "dark greyish-brown."

The males are smaller than the females, and both genders vary greatly in size depending on the fertility of the water. You should size your flies based on naturals you collect or on the local fly shops; don't just buy a few from a national outlet and expect them to match your river's hatch.

Specimens of the Mayfly Species Ephemera guttulata

1 Female Dun
Female Ephemera guttulata (Green Drake) Mayfly Dun
It's about time I got a green drake on this site!
1 Male Spinner
Male Ephemera guttulata (Green Drake) Mayfly Spinner
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.
1 Female Spinner

1 Streamside Picture of Ephemera guttulata Mayflies:

Recent Discussions of Ephemera guttulata

Green Drake Hatch Temp?
1 replies
Posted by NEMatt on May 23, 2014
Last reply on May 24, 2014 by Entoman

I was looking for a water temperature range for the Green Drake hatch. Anyone know?
GD Shuck
10 replies
Posted by Martinlf on May 29, 2013
Last reply on Jun 2, 2013 by Crepuscular
Jason's photo of a GD shuck suggests that at hatch time the backs of the nymphs may be a greyish or grey olive color. Possibly useful information, if this is an accurate surmise.
Emergence period of green drakes
5 replies
Posted by Beardius on Aug 1, 2008
Last reply on Dec 5, 2008 by Beardius
Emergence periods for green drakes usually run for 7-10 days in most streams. However, there are streams in the east where emergence periods are prolonged by some of the nymphs being parasitized by Nanocladius and Epoicocladius midge larvae. In these streams, emergence may be prolonged to 21 days. Unparasitized nymphs emerge before parasitized nymphs, with each group showing separate peaks of emergence about a week apart. This is based upon my own research on green drake emergence in streams with these midge species.

My question here is this: does anybody know of streams that have this type of prolonged emergence (2-3 weeks) in NY, PA, MD, or WV?
Green Drake Hatch Frustrations
7 replies
Posted by Billy on Jun 6, 2007
Last reply on Jun 12, 2007 by GONZO
We were fortunate this past weekend to be on Pine Creek during the Green Drake hatch. The spinner fall was incredible. A question I have is why do we miss so many strikes and yet, using the same techniques, the ones we do catch and release practically hook themselves. We were getting strikes on Green Drake Duns and Cripples and Spinners.

One individual described it to us that after observing the trout underwater during a Green Drake hatch, many of the strikes pull a small part of the fly (wing, leg) underwater and they swirl and swallow it there. If that is true, then I can rationalize missing more than 18 fish this weekend. If anyone has observed this please post your observations. Normally we do not have such a great contrast in miss to hookup ratio.

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