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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Kogotus Stonefly Nymph Kogotus Stonefly Nymph

Dorsal view of a Kogotus (Perlodidae) Stonefly Nymph from Mystery Creek #199 in Washington

This one pretty clearly keys to Kogotus, but it also looks fairly different from specimens I caught in the same creek about a month later in the year. With only one species of the genus known in Washington, I'm not sure about the answer to this ID.

8 Recently Added Photos

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 Baetis tricaudatus (Blue-Winged Olive) Mayfly Spinner Pictures

Ruler view of a Female Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho The smallest ruler marks are 1 mm.

Dorsal view of a Female Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho

Ventral view of a Female Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho

I looked closer under a microscope to see that the second longitudinal vein of the hind wing does not fork (ie it isn't Diphetor hageni).

Female Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho

Female Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho

Lateral view of a Female Baetis tricaudatus (Baetidae) (Blue-Winged Olive) Mayfly Spinner from the Henry's Fork of the Snake River in Idaho

This mayfly was collected from the Henry's Fork of the Snake River in Idaho on July 31st, 2020 and added to Troutnut.com by Troutnut on August 16th, 2020.

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