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Artistic view of a Male Pteronarcys californica (Pteronarcyidae) (Giant Salmonfly) Stonefly Adult from the Gallatin River in Montana
Salmonflies
Pteronarcys californica

The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.

Lateral view of a Female Sweltsa borealis (Chloroperlidae) (Boreal Sallfly) Stonefly Adult from Harris Creek in Washington
I was not fishing, but happened to be at an unrelated social event on a hill above this tiny creek (which I never even saw) when this stonefly flew by me. I assume it came from there. Some key characteristics are tricky to follow, but process of elimination ultimately led me to Sweltsa borealis. It is reassuringly similar to this specimen posted by Bob Newell years ago. It is also so strikingly similar to this nymph from the same river system that I'm comfortable identifying that nymph from this adult. I was especially pleased with the closeup photo of four mites parasitizing this one.
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 undulata (Small Western Red Quill) Mayfly Spinner Pictures

This male was collected at the same time as this female and is likely the same species.

It keys pretty clearly to Rhithrogena undulata using the key in Traver 1935, although the size is larger than expected for that species in that source.

Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Dorsal view of a Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Ruler view of a Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana The smallest ruler marks are 1 mm.
Ventral view of a Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana
Male Rhithrogena undulata (Heptageniidae) (Small Western Red Quill) Mayfly Spinner from the Madison River in Montana

This mayfly was collected from the Madison River in Montana on July 1st, 2019 and added to Troutnut.com by Troutnut on July 18th, 2019.


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Male Rhithrogena undulata (Small Western Red Quill) Mayfly Spinner Pictures

Collection details
Location: Madison River, Montana
Date: July 1st, 2019
Added to site: July 18th, 2019
Author: Troutnut
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