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**Mayfly Genus Epeorus (Little Maryatts)**

Mayflies

Caddisflies

Stoneflies

Taxonomic Navigation -?-

Kingdom Animalia (Animals)

» Phylum Arthropoda (Arthropods)

» Class Insecta (Insects)

» Order Ephemeroptera (Mayflies)

» Family Heptageniidae (March Browns, Cahills, Quill Gordons)

» Genus Epeorus (Little Maryatts)

Species in Epeorus
Epeorus albertaePink Lady	0	0
Epeorus deceptivus	0	0
Epeorus fragilis	0	0
Epeorus frisoni	0	0
Epeorus grandis	0	0
Epeorus longimanusSlate Brown Dun	0	0
Epeorus pleuralisQuill Gordon	0	0
Epeorus punctatus	0	0
Epeorus suffusus	0	0
Epeorus vitreusSulphur	0	0

9 species aren't included.

Common Names

Match	Common Name
	Little Maryatts
	Western Gordon Quills
	Yellow Quills
	Small Western Gordon Quills
	Slate Cream Duns
	Pink Ladies
	Slate Brown Duns
	Slate Maroon Drakes

Pictures Below ↓

There is remarkable variety of form and color within this prolific genus of fast-water mayflies. Different species are found across the country, and several cause good hatches. Fly anglers are likely to encounter the lesser species on occasion, too.

The best Epeorus hatch in the East is Epeorus pleuralis, the famous Quill Gordon, the first abundant large mayfly hatch of the year. Epeorus vitreus comes a little later and is important in both the East and Midwest.

In the West, Epeorus longimanus dominates in fast, high-altitude streams, while Epeorus albertae inhabits slower and lower waters.

Hatching Behavior

All Epeorus duns emerge from their nymphal shucks (

View Full Size

Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.

Shuck: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.) below the surface, often while still attached to the stream bed. Most species (with the exception of Epeorus pleuralis) take to the air quickly after emerging. These two factors make wet emerger patterns especially effective during Epeorus hatches.

Spinner Behavior

Female Epeorus spinners oviposit by making repeated dips to the surface. They deposit a few eggs, sometimes rest briefly, and then take off for another run.

Nymph Biology

Most Epeorus species require fast, pure water flowing over gravel or boulders. Some can inhabit moderate currents.

Pictures of 52 Mayfly Specimens in the Genus Epeorus:

Specimen Page:12 3 4...6

Male Epeorus pleuralis (Quill Gordon) Mayfly Dun

View 9 PicturesI kept this specimen after photographing it and it molted into a spinner in perfect condition, which I photographed here.

Collected April 30, 2007 from Dresserville Creek in New York
Added to Troutnut.com by Troutnut on May 3, 2007

Male Epeorus pleuralis (Quill Gordon) Mayfly Spinner

View 10 PicturesI spent (Spent: The wing position of many aquatic insects when they fall on the water after mating. The wings of both sides lay flat on the water. The word may be used to describe insects with their wings in that position, as well as the position itself.) most of the day looking for Epeorus pluralis duns or spinners without any luck on the major Catskill rivers. Finally in the evening I arrived at a small stream somebody had recommended, and when I got out of the car I was happy to find that I had parked in the middle of a cloud of male spinners.

Collected April 19, 2006 from Mongaup Creek in New York
Added to Troutnut.com by Troutnut on April 22, 2006

Male Epeorus albertae (Pink Lady) Mayfly Spinner

View 14 Pictures

Collected July 11, 2017 from the North Fork Stillaguamish River in Washington
Added to Troutnut.com by Troutnut on July 12, 2017

Specimen Page:12 3 4...6

9 Underwater Pictures of Epeorus Mayflies:

Underwater Photo Page:12

View Full Size and Comment (2.1X larger)

In this picture: Mayfly Genus Epeorus (Little Maryatts) and Mayfly Family Baetidae (Blue-Winged Olives).

StateNew York

LocationMongaup Creek

Date TakenApr 19, 2006

Date AddedApr 22, 2006

AuthorTroutnut

CameraPENTAX Optio WPi

View Full Size and Comment (2X larger)

In this picture: Mayfly Genus Epeorus (Little Maryatts), Insect Order Trichoptera (Caddisflies), and Mayfly Family Baetidae (Blue-Winged Olives).

StateNew York

LocationMongaup Creek

Date TakenApr 19, 2006

Date AddedApr 22, 2006

AuthorTroutnut

CameraPENTAX Optio WPi

View Full Size and Comment (2X larger)

In this picture: Mayfly Genus Epeorus (Little Maryatts) and Mayfly Family Baetidae (Blue-Winged Olives).

StateNew York

LocationMongaup Creek

Date TakenApr 19, 2006

Date AddedApr 22, 2006

AuthorTroutnut

CameraPENTAX Optio WPi

Underwater Photo Page:12

Recent Discussions of Epeorus

Distance between the eyes of male Epeorus

Posted by Troutnut on May 3, 2007

There has been some discussion here before about Epeorus identification, especially the distance between the eyes of the adult males, which is one identifying characteristic. The keys say that the distance should be "less than the width of the median ocellus," but I have collected a few male duns that didn't quite fit that requirement.

We figured they were Epeorus anyway, so it's not a big deal, but a new specimen I collected sheds a bit of light on the question.

I collected a dun whose eyes were also a bit far apart, which you can see here:

http://www.troutnut.com/specimen/681

Then it molted into a spinner:

http://www.troutnut.com/specimen/682

The spinner's eyes were really almost touching, well within the description of the genus. So that answers our question: the duns may have a little wider spread and the gap will close up in the spinners.

Reply Synonym of vitreus 3 Replies »

Posted by GONZO on Oct 4, 2006

Last reply on Oct 4, 2006 by Troutnut

I believe rubidus = vitreus

There is 1 more topic.

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Jargon Defined:

Duns: Mayflies have two adult stages. They first emerge from the water as duns (scientifically known as the subimago stage). They then molt into the spinner (imago) stage, in which they mate and die. Sometimes the word "dun" is confusingly used to refer to a brownish gray color in fly tying materials.

Oviposit: To lay eggs.

View Full Size

Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.

Shucks: The shed exoskeleton left over when an insect molts into its next stage or instar. Most often it describes the last nymphal or pupal skin exited during emergence into a winged adult.

Spent: The wing position of many aquatic insects when they fall on the water after mating. The wings of both sides lay flat on the water. The word may be used to describe insects with their wings in that position, as well as the position itself.

Spinner: There are two winged stages of adult mayflies. They emerge from the water as duns, molt on land (usually) into their fully mature stage, spinners. As spinners, they mate, lay eggs, and die.

Useful References:

Arbona, Fred Jr. 1989. Mayflies, the Angler, and the Trout. Nick Lyons Books.

Caucci, Al and Nastasi, Bob. 2004. Hatches II. The Lyons Press.

Knopp, Malcolm and Robert Cormier. 1997. Mayflies: An Angler's Study of Trout Water Ephemeroptera . The Lyons Press.