Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York

Blue-winged Olives
Baetis

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.

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Female Sweltsa borealis (Boreal Sallfly) Stonefly Adult Female Sweltsa borealis (Boreal Sallfly) Stonefly Adult

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.

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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 Epeorus albertae (Pink Lady) Mayfly Spinner Pictures

Male Epeorus albertae (Heptageniidae) (Pink Lady) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho

Lateral view of a Male Epeorus albertae (Heptageniidae) (Pink Lady) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho

Ventral view of a Male Epeorus albertae (Heptageniidae) (Pink Lady) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho

Dorsal view of a Male Epeorus albertae (Heptageniidae) (Pink Lady) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho

Ruler view of a Male Epeorus albertae (Heptageniidae) (Pink Lady) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho The smallest ruler marks are 1 mm.

This mayfly was collected from the Henry's Fork of the Snake River in Idaho on August 1st, 2020 and added to Troutnut.com by Troutnut on August 18th, 2020.

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