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.

Sunlight perfectly strikes the trees at a bend in the Foss River in the Washington Cascades.

From the Foss River in Washington

Stream photos

Featured on the forum

Re: Trico emergers
In the Mayfly Genus Tricorythodes by Bwoklink (Martinlf replied)

Re: Trico Tips
In the Mayfly Genus Tricorythodes by Martinlf

Re: UV spectrum and trout
In General Discussion by Martinlf

Re: closing the gender gap in flyfishing
In General Discussion by Konchu (Smallflyguy replied)

Re: Fishing Kupa River, Slovenia
In Fishing Reports by Slocum (Fish1 replied)

Glossosoma (Little Brown Short-horned Sedge) Caddisfly Larva Glossosoma (Little Brown Short-horned Sedge) Caddisfly Larva

Dorsal view of a Glossosoma (Glossosomatidae) (Little Brown Short-horned Sedge) Caddisfly Larva from the Yakima River in Washington

I caught this tiny larva without a case, but it seems to key pretty clearly to to Glossosomatidae. From there, the lack of sclerites on the mesonotum points to either Glossosoma or Anagapetus. Although it's difficult to see in a 2D image from the microscope, it's pretty clear in the live 3D view that the pronotum is only excised about 1/3 of its length to accommodate the forecoxa, not 2/3, which points to Glossosoma at Couplet 5 of the Key to Genera of Glossosomatidae Larvae.

11 Recently Added Photos

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.

Ecdyonurus criddlei (Little Slate-Winged Dun) Mayfly Nymph Pictures

This is an interesting Heptageniid mayfly since in western Montana it is only found in cold lakes, especially those in Glacier National Park.

This mayfly was collected from Kintla Lake in Montana on July 31st, 2007 and added to Troutnut.com by Bnewell on June 26th, 2011.

Discussions of this Nymph

Ecdyonurus nymphs

Posted by Jmw975 on Dec 11, 2012

Last reply on Dec 11, 2012 by Jmw975

Hi all,
These specimens are in great shape!

the lower nymph in this photo is definitely not E. criddlei, but E. simplicoides. E. simplicioides has that distinctive color pattern with the pair of rectangular pale markings on tergum 4 and no median markings on the other terga.

The upper specimen is probably E. criddlei, but seems to have more extensive pale markings than specimens from further west.

cheers,
Jeff

Start a Discussion of Nymph