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.

This topic is about the Caddisfly Genus Chimarra

Chimarra aterrima is the most important species.

Example specimens

Posts: 5
Hellgie on Mar 30, 2010March 30th, 2010, 12:03 pm EDT
I would like to see a picture of an emerging Chimarra or a pupa stage before emerging if anyone has one. I am baffled and curious to how and when they change from a yellow/orange larva to a black adult fly. Also, what would be a good emerger pattern for this fly? Lafontaine emerger in what color?
Martinlf's profile picture
Palmyra PA

Posts: 3047
Martinlf on Mar 31, 2010March 31st, 2010, 11:48 pm EDT

I'm no expert on Chimarra, and hope one of the caddis guys will give you a good answer. We have several but they haven't been on recently (perhaps they're out collecting caddis larvae). I'd guess that a black Lafontaine would work, but it's just a guess. I've had my best luck with a CDC adult for this caddis, black body and wing.
"He spread them a yard and a half. 'And every one that got away is this big.'"

--Fred Chappell
Site Editor
"Bear Swamp," PA

Posts: 1681
GONZO on Apr 1, 2010April 1st, 2010, 1:55 am EDT

Concentrations of little black caddisflies that are seen emerging on the surface are probably not Chimarra. In the information in this section, Jason mentions that the pupae usually crawl out to emerge. They will even use your waders for that purpose if you stand for any length of time in an active emergence site. (You'll notice the freshly emerged adults accumulating just above the waterline.) Rather than a surface imitation like the LaFontaine emerger, I find that something like a small blackish soft-hackle crawled along the bottom usually works best.

As for the color, the transformation from larva to pupa is very dramatic in many ways, and caddisfly larvae are often very differently colored than the emerging pupae/adults. See a similar discussion by clicking on the "Pupa color?" thread in the same section.
Martinlf's profile picture
Palmyra PA

Posts: 3047
Martinlf on Apr 2, 2010April 2nd, 2010, 3:09 am EDT
Thanks, Gonzo, for the clarification. Again you give me some ideas on what to do when I'm trouting, this time, when black caddis are about.
"He spread them a yard and a half. 'And every one that got away is this big.'"

--Fred Chappell
Posts: 5
Hellgie on Apr 6, 2010April 6th, 2010, 4:54 pm EDT
Thanks for all the replies. I'll have to try the Peacock and Starling pattern. I have found that a small size 16 and 18 prince nymph also works well during the hatch.

Posts: 1
Gazzer on Apr 9, 2018April 9th, 2018, 3:58 pm EDT
I would too, so far I haven't come across one.
I once fished a hatch of chimarra cadiss on the lower east branch in 45 degree water.
The pupa popped to the surface in small groups it seemed.the were very buoyant. The pupa pulsed on the surface migrating themselves twards the shore. Some found my waders and split thier shucks out of the water sqirming and wiggling out to adults.
The pupa were irridecent peacock hearl like color with the ribbing like peacock quill.
The trout were feeding heavily on them and I managed to catch 2 very nice browns on a peacock quill pupa recommend by Budge at the Beaverkill Angler. Before the time of the cell phone camera and video I only have memory.
I tried to create such floating pupa with foam not very successful I let it go to fish other hatches.

Quick Reply

Related Discussions

Last Reply
Apr 5, 2012
by Entoman
May 18, 2020
by Wbranch
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy