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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.

Lateral view of a Onocosmoecus (Limnephilidae) (Great Late-Summer Sedge) Caddisfly Larva from the Yakima River in Washington
This specimen keys pretty easily to Onocosmoecus, and it closely resembles a specimen from Alaska which caddis expert Dave Ruiter recognized as this genus. As with that specimen, the only species in the genus documented in this area is Onocosmoecus unicolor, but Dave suggested for that specimen that there might be multiple not-yet-distinguished species under the unicolor umbrella and it would be best to stick with the genus-level ID. I'm doing the same for this one.
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 Ephemerella invaria (Sulphur) Mayfly Dun Pictures

Lateral view of a Male Ephemerella invaria (Ephemerellidae) (Sulphur) Mayfly Dun from the Little Juniata River in Pennsylvania
Artistic view of a Male Ephemerella invaria (Ephemerellidae) (Sulphur) Mayfly Dun from the Little Juniata River in Pennsylvania
Ruler view of a Male Ephemerella invaria (Ephemerellidae) (Sulphur) Mayfly Dun from the Little Juniata River in Pennsylvania The smallest ruler marks are 1 mm.
Male Ephemerella invaria (Ephemerellidae) (Sulphur) Mayfly Dun from the Little Juniata River in Pennsylvania
Male Ephemerella invaria (Ephemerellidae) (Sulphur) Mayfly Dun from the Little Juniata River in Pennsylvania
Ventral view of a Male Ephemerella invaria (Ephemerellidae) (Sulphur) Mayfly Dun from the Little Juniata River in Pennsylvania

This mayfly was collected from the Little Juniata River in Pennsylvania on May 25th, 2007 and added to Troutnut.com by Troutnut on June 4th, 2007.

Discussions of this Dun

need a good pattern
1 replies
Posted by Anttam on May 19, 2008
Last reply on Jan 7, 2009 by Phishheaduj
any cdc patterns you nuts know of for Sulfpurs?
looking for a site with instructions or any help

Start a Discussion of Dun

Male Ephemerella invaria (Sulphur) Mayfly Dun Pictures

Collection details
Location: Little Juniata River, Pennsylvania
Date: May 25th, 2007
Added to site: June 4th, 2007
Author: Troutnut
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