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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.

Artistic view of a Perlodidae (Springflies and Yellow Stones) Stonefly Nymph from the Yakima River in Washington
This one seems to lead to Couplet 35 of the Key to Genera of Perlodidae Nymphs and the genus Isoperla, but I'm skeptical that's correct based on the general look. I need to get it under the microscope to review several choices in the key, and it'll probably end up a different Perlodidae.
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 Onocosmoecus unicolor (Great Late-Summer Sedge) Caddisfly Adult Pictures

I first just assumed this was Dicosmoecus based on anglers' conventional wisdom since it's a large orange "October caddis," but Creno set me straight. I should have keyed it out. After another look under the microscope, it lacks an anepisternal wart on the mesopleuron, which rules out Dicosmoecus. The midtibiae have 2 apical spurs and 1 pre-apical spur, and from there the color pattern of the wing points to Onocosmoecus. The location then narrows the species to unicolor.

Lateral view of a Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Ruler view of a Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington The smallest ruler marks are 1 mm.
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Ventral view of a Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington
Dorsal view of a Male Onocosmoecus unicolor (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Adult from the Yakima River in Washington

This caddisfly was collected from the Yakima River in Washington on September 17th, 2020 and added to Troutnut.com by Troutnut on September 19th, 2020.

Discussions of this Adult

mean one thing, write another?
2 replies
Posted by Creno on Sep 19, 2020
Last reply on Sep 20, 2020 by Creno
Onocosmoecus unicolor?

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Male Onocosmoecus unicolor (Great Late-Summer Sedge) Caddisfly Adult Pictures

Collection details
Location: Yakima River, Washington
Date: September 17th, 2020
Added to site: September 19th, 2020
Author: Troutnut
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