Header image
Enter a name
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.

Case view of a Pycnopsyche guttifera (Limnephilidae) (Great Autumn Brown Sedge) Caddisfly Larva from the Yakima River in Washington
It's only barely visible in one of my pictures, but I confirmed under the microscope that this one has a prosternal horn and the antennae are mid-way between the eyes and front of the head capsule.

I'm calling this one Pycnopsyche, but it's a bit perplexing. It seems to key definitively to at least Couplet 8 of the Key to Genera of Limnephilidae Larvae. That narrows it down to three genera, and the case seems wrong for the other two. The case looks right for Pycnopsyche, and it fits one of the key characteristics: "Abdominal sternum II without chloride epithelium and abdominal segment IX with only single seta on each side of dorsal sclerite." However, the characteristic "metanotal sa1 sclerites not fused, although often contiguous" does not seem to fit well. Those sclerites sure look fused to me, although I can make out a thin groove in the touching halves in the anterior half under the microscope. Perhaps this is a regional variation.

The only species of Pycnopsyche documented in Washington state is Pycnopsyche guttifera, and the colors and markings around the head of this specimen seem to match very well a specimen of that species from Massachusetts on Bugguide. So I am placing it in that species for now.

Whatever species this is, I photographed another specimen of seemingly the same species from the same spot a couple months later.
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.

Siphlonurus autumnalis (Gray Drake) Mayfly Nymph Pictures

This mayfly was collected from Crazy Beaver Spring in Montana on August 31st, 2007 and added to Troutnut.com by Bnewell on June 28th, 2011.

Discussions of this Nymph

Mix-up
2 replies
Posted by GONZO on Jul 2, 2011
Last reply on Jul 2, 2011 by Troutnut
I've really been enjoying looking at Dr. Newell's additions to the "Aquatic Insect Encyclopedia," but there seems to have been some sort of mix-up here. The 2nd photograph is an female ephemerellid dun, possibly something like Ephemerella tibialis.

Start a Discussion of Nymph

Siphlonurus autumnalis (Gray Drake) Mayfly Nymph Pictures

Collection details
Location: Crazy Beaver Spring, Montana
Date: August 31st, 2007
Added to site: June 28th, 2011
Author: Bnewell
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy