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.

Stream photos

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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.

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Male Cinygmula (Dark Red Quill) Mayfly Spinner Pictures

I'm unsure of the ID on this one; keys put it closest to Cinygmula reticulata, but I'm very doubtful of the species and not positive on the genus. Epeorus is another possibility, but I don't know which species it would be.

This one was collected in association with a female dun probably of a different family.

Lateral view of a Male Cinygmula (Heptageniidae) (Dark Red Quill) Mayfly Spinner from the South Fork Stillaguamish River in Washington

Male Cinygmula (Heptageniidae) (Dark Red Quill) Mayfly Spinner from the South Fork Stillaguamish River in Washington

Dorsal view of a Male Cinygmula (Heptageniidae) (Dark Red Quill) Mayfly Spinner from the South Fork Stillaguamish River in Washington

Ventral view of a Male Cinygmula (Heptageniidae) (Dark Red Quill) Mayfly Spinner from the South Fork Stillaguamish River in Washington

Ruler view of a Male Cinygmula (Heptageniidae) (Dark Red Quill) Mayfly Spinner from the South Fork Stillaguamish River in Washington The smallest ruler marks are 1/16".

This mayfly was collected from the South Fork Stillaguamish River in Washington on July 1st, 2017 and added to Troutnut.com by Troutnut on July 2nd, 2017.

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