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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.

Ventral view of a Hydropsyche (Hydropsychidae) (Spotted Sedge) Caddisfly Larva from the Yakima River in Washington
With a bit of help from the microscope, this specimen keys clearly and unsurprisingly to Hydropsyche.
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.

Isonychia bicolor (Mahogany Dun) Mayfly Nymph Pictures

This Isonychia bicolor nymph from the Catskills displays the prominent white stripe sometimes characteristic of its species. This is the first such specimen I've photographed, because members of the same species in the Upper Midwest have a more subdued stripe (and were once thought to be a different species, Isonychia sadleri). The striking coloration on this eastern nymph is more appealing.

Artistic view of a Isonychia bicolor (Isonychiidae) (Mahogany Dun) Mayfly Nymph from the Beaverkill River in New York
Dorsal view of a Isonychia bicolor (Isonychiidae) (Mahogany Dun) Mayfly Nymph from the Beaverkill River in New York
Isonychia bicolor (Isonychiidae) (Mahogany Dun) Mayfly Nymph from the Beaverkill River in New York
Isonychia bicolor (Isonychiidae) (Mahogany Dun) Mayfly Nymph from the Beaverkill River in New York
Isonychia bicolor (Isonychiidae) (Mahogany Dun) Mayfly Nymph from the Beaverkill River in New York
Isonychia bicolor (Isonychiidae) (Mahogany Dun) Mayfly Nymph from the Beaverkill River in New York
This species does not behave well for the camera, so  I eventually killed this specimen in alcohol to get a better picture of the mouth parts.  This resulting unnatural pose shows them well.

Isonychia bicolor (Isonychiidae) (Mahogany Dun) Mayfly Nymph from the Beaverkill River in New York

This mayfly was collected from the Beaverkill River in New York on April 19th, 2006 and added to Troutnut.com by Troutnut on April 21st, 2006.

Discussions of this Nymph

Sare
Posted by Sare on Jan 28, 2020
Last reply on Jan 28, 2020 by Sare
I just love your webpage and all the info you guys provide and the pics are incredible.
Please keep up the great work you are doing - no other webpage comes close to you guys.
Thanks Sare

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Isonychia bicolor (Mahogany Dun) Mayfly Nymph Pictures

Collection details
Location: Beaverkill River, New York
Date: April 19th, 2006
Added to site: April 21st, 2006
Author: Troutnut
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