Mayfly Genus Epeorus (Little Maryatts)
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)
10 species aren't included.
Common Names
| Match | Common Name |
 | Little Maryatts |
 | Small Western Gordon Quills |
| Yellow Quills |
| Slate Maroon Drakes |
| Slate Brown Duns |
| Western Gordon Quills |
| Pink Ladies |
| Slate Cream Duns |
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 (
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Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.
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.29 Mayfly Specimens in the Genus Epeorus:
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.
View 9 PicturesI kept this specimen after photographing it and it molted into a spinner in perfect condition, which I photographed here.Region: Northeast
Collected Apr 30, 2007
Added May 3, 2007
Epeorus pleuralis (Quill Gordon) Mayfly Dun
View 9 Pictures
View 9 PicturesRegion: Catskills
Collected May 7, 2005
Added May 16, 2006
Epeorus vitreus (Sulphur) Mayfly Spinner
View 9 Pictures
View 9 PicturesRegion: Northeast
Collected Sep 19, 2006
Added Oct 4, 2006
3 Streamside Pictures of Epeorus Mayflies:
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This Epeorus pleuralis nymph tried to hatch into a dun while attached to this rock and apparently got stuck. This species is supposed to emerge from its nymphal shuck (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.) on the bottom of the stream and swim to the surface as a bedraggled dun. It seems more like this one was trying to crawl out onto a rock to emerge. The rock itself is covered with a thin layer of fast water in a riffle, and apparently it prevented the dun from making any headway. You can see the dun's eyes and a bit of the mesonotum (Mesonotum: The top of the insect mesothorax.) if you look closely.
In this picture: Mayfly Species Epeorus pleuralis (Quill Gordon).
Here's an underwater view of the pupal shucks of several already-emerged Brachycentrus numerosus caddisflies.
In this picture: Mayfly Species Epeorus pleuralis (Quill Gordon).
A freshly hatched Quill Gordon dun looks out across the surface of the Catskill stream she just escaped.
In this picture: Mayfly Species Epeorus pleuralis (Quill Gordon).
In this picture: Mayfly Species Epeorus pleuralis (Quill Gordon).
Epeorus nymphs with their flat profile and wide gills are excellent at clinging to rocks in fast water. This one clings to the surface of a rock covered with only a thin layer of water rushing over it in a riffle.
In this picture: Mayfly Genus Epeorus (Little Maryatts).
In this picture: Mayfly Genus Epeorus (Little Maryatts).
9 Underwater Pictures of Epeorus Mayflies:
In this picture: Mayfly Genus Epeorus (Little Maryatts) and Mayfly Family Baetidae (Blue-Winged Olives).
In this picture: Mayfly Genus Epeorus (Little Maryatts) and Mayfly Family Baetidae (Blue-Winged Olives).
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.
ReplySynonym of vitreus 3 Replies »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.
I believe rubidus = vitreus
Reply
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