Header image
Enter a name
Artistic view of a Male Pteronarcys californica (Pteronarcyidae) (Giant Salmonfly) Stonefly Adult from the Gallatin River in Montana
Pteronarcys californica

The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.

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.

Fredw has attached these 4 pictures to aid in identification. The message is below.
Vancouver Island, BC

Posts: 10
Fredw on Jul 4, 2013July 4th, 2013, 8:12 pm EDT
I believe this may be the dun from my previous post, but would like some clarification. The netting that you see is actually from my landing net.the spacing across three holes in the landing net is 11.74mm. not sure if the first pic is fully emerged

thanks for your help

Taxon's profile picture
Site Editor
Plano, TX

Posts: 1311
Taxon on Jul 4, 2013July 4th, 2013, 9:39 pm EDT
Hi Fred,

Yes, I believe it to be a Callibaetis female subimago, but would sure be a lot more comfortable making that call if I could see its hind wing. :-)
Best regards,
Roger Rohrbeck
Entoman's profile picture
Northern CA & ID

Posts: 2604
Entoman on Jul 10, 2013July 10th, 2013, 10:42 pm EDT
Hi Fred,

Now that is the way Callibaetis (Speckled Duns) usually look. Fairly confident it is C. ferrugineus hageni. The clear wings on your earlier topic's specimen made me cautious but I have no doubts about this one. Is it the same species? Most likely, as the male spinners can have clear wings without the blotches normally associated with this genus. Its nymphs are very good swimmers and actively dart around in the weeds prior to and during hatching. They are a favorite trout food and by far our most important western stillwater mayfly.
"It's not that I find fishing so important, it's just that I find all other endeavors of Man equally unimportant... And not nearly as much fun!" Robert Traver, Anatomy of a Fisherman

Quick Reply

Related Discussions

Last Reply
May 26, 2018
by Taxon
Aug 9, 2013
by Taxon
Mar 24, 2011
by FredH
Nov 17, 2012
by FredH
Nov 4, 2011
by Dinerobyn
Apr 8, 2010
by Taxon
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy