Header image
Enter a name
Lateral view of a Female Hexagenia limbata (Ephemeridae) (Hex) Mayfly Dun from the Namekagon River in Wisconsin
Hex Mayflies
Hexagenia limbata

The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.

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.

Female Timpanoga hecuba (Great Red Quill) Mayfly Dun Pictures

This specimen is 14 mm. Technically this is the subspecies T. h. hecuba. The Cascades, Sierras and further West is where the other subspecies, T. h. pacifica is found. The Great Basin seems to have formed a barrier preventing any overlap in their distribution.

This mayfly was collected from Mystery Creek #178 in Idaho on September 15th, 2013 and added to Troutnut.com by Entoman on September 23rd, 2013.

Discussions of this Dun

Great Red Quill
19 replies
Posted by Entoman on Sep 22, 2013
Last reply on Oct 2, 2013 by Jmd123
This critter provided some excellent fishing a little after lunch the day this specimen was collected. They seem to be very delicate in handling as it expired inverted in the fly box while setting up for the photos. On this particular day the duns were up and away with little if any time spent on the water. The fish were feeding on ascending nymphs well below the surface. The hatch was a perfect fishing density and the fish were glutted with these large guys. To the naked eye they appeared chocolate brown with tan rings. The wings were a med. dun. Notice how stout their tapered abdomens are... Real chunks of protein!

The duns did not darken as they aged and as the photos show, there is little (if any) difference in the appearance between the dorsal and ventral surfaces. Very unusual for an ephemerellid...

Start a Discussion of Dun

Female Timpanoga hecuba (Great Red Quill) Mayfly Dun Pictures

Collection details
Location: Mystery Creek #178, Idaho
Date: September 15th, 2013
Added to site: September 23rd, 2013
Author: Entoman
Troutnut.com is copyright © 2004-2023 (email Jason). privacy policy