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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.

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.

Onocosmoecus (Great Late-Summer Sedge) Caddisfly Larva Pictures

See the forum discussion for discussion with a caddis expert (Dave Ruiter / Creno) about the identification of this specimen. I'm a bit perplexed because some gills seem to have more than 4 branches, which would lead in a different direction at Couplet 18 of the Key to Genera of Limnephilidae Larvae, but Dave knew his stuff a lot better than I did. He was convinced this is Onocosmoecus. The current range maps would put this in Onocosmoecus unicolor as the only option, but he believed there are probably multiple not-yet-distinguished species under that umbrella and suggested keeping this one's ID at the genus level for that reason.

Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Case view of a Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Ruler view of a Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska The smallest ruler marks are 1 mm.
Ventral view of a Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Dorsal view of a Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska
Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Chena River in Alaska

This caddisfly was collected from the Chena River in Alaska on May 10th, 2008 and added to Troutnut.com by Troutnut on April 20th, 2011.

Discussions of this Larva

one of the dicosmoecins
3 replies
Posted by Creno on Apr 26, 2011
Last reply on Apr 28, 2011 by Troutnut
Most likely Onocosmoecus but I want to look at a couple critters.
I like the new site look. It will take awhile to look around.
creno

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Onocosmoecus (Great Late-Summer Sedge) Caddisfly Larva Pictures

Collection details
Location: Chena River, Alaska
Date: May 10th, 2008
Added to site: April 20th, 2011
Author: Troutnut
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