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.

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Female Baetidae (Blue-Winged Olive) Mayfly Spinner Pictures

This is one of the smallest mayflies I've ever collected, about 3mm long.

Female Baetidae (Blue-Winged Olive) Mayfly Spinner from the West Branch of Owego Creek in New York

Lateral view of a Female Baetidae (Blue-Winged Olive) Mayfly Spinner from the West Branch of Owego Creek in New York

Ventral view of a Female Baetidae (Blue-Winged Olive) Mayfly Spinner from the West Branch of Owego Creek in New York

Ruler view of a Female Baetidae (Blue-Winged Olive) Mayfly Spinner from the West Branch of Owego Creek in New York The smallest ruler marks are 1 mm.

This mayfly was collected from the West Branch of Owego Creek in New York on August 9th, 2006 and added to Troutnut.com by Troutnut on August 11th, 2006.

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