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.

Firehole River Sunset

From the Firehole River in Wyoming

Stream photos

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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.

Acroneuria lycorias (Golden Stone) Stonefly Nymph Pictures

This stonefly was collected from the Namekagon River in Wisconsin on January 13th, 2004 and added to Troutnut.com by Troutnut on January 25th, 2006.

Discussions of this Nymph

Moved to Acroneuria lycorias

Posted by Entoman on Apr 8, 2013

Last reply on Apr 8, 2013 by Entoman

Here's a good example of an Acroneurinae species other than A. abnormis that can have a dark body. The presence of anal gills and a thick occiptal bar impinged by a black spot in the middle point to lycorias. The picture is dark and the angle gives the head the flat based triangle look of the Perlinae, but if you enlarge the photo and look closely, the pale occipital bar at the back of the head is located where the ridge should be, precluding that subfamily.

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