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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.

Dorsal view of a Pycnopsyche guttifera (Limnephilidae) (Great Autumn Brown Sedge) Caddisfly Larva from the Yakima River in Washington
This specimen appears to be of the same species as this one collected in the same spot two months earlier. The identification of both is tentative. This one suffered some physical damage before being photographed, too, so the colors aren't totally natural. I was mostly photographing it to test out some new camera setting idea, which worked really well for a couple of closeups.
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.

Male Rhithrogena hageni (Western Black Quill) Mayfly Spinner Pictures

This specimen was one of several males fluttering around over the river late in the afternoon near the Twin Falls trailhead on May 14. It's pretty clearly the same species as this one collected on June 22 five years earlier.

I also collected a nymph of presumably the same species in the riffle beneath these dancing males.

Lateral view of a Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
Dorsal view of a Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
The anastomosing of the crossveins in the stigmatic area is pretty light compared to other Rhithrogena I've collected. That area is also faintly darker, something harder to see in the photos but fairly conspicuous in the living insect.

Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
Body length 11 mm, wing length 12 mm.

Ruler view of a Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington The smallest ruler marks are 1 mm.
Ventral view of a Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
Ventral view

Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
Dorsal view

Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
Artistic view of a Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
Ventral view of the terminalia through my microscope. This was a different specimen of what seems to be the same species, collected on the same river a week later.

Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington
Another ventral view of the terminalia through my microscope. This was a different specimen of what seems to be the same species, collected on the same river a week later.

Male Rhithrogena hageni (Heptageniidae) (Western Black Quill) Mayfly Spinner from the South Fork Snoqualmie River in Washington

This mayfly was collected from the South Fork Snoqualmie River in Washington on May 14th, 2022 and added to Troutnut.com by Troutnut on May 15th, 2022.


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Male Rhithrogena hageni (Western Black Quill) Mayfly Spinner Pictures

Collection details
Location: South Fork Snoqualmie River, Washington
Date: May 14th, 2022
Added to site: May 15th, 2022
Author: Troutnut
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