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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.

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.

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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