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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.

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.
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BrettHRomer has attached these 6 pictures to aid in identification. The message is below.
Posts: 2
BrettHRomer on May 7, 2008May 7th, 2008, 2:12 am EDT
Hey guys...wanted to say we've had an excellent couple of weeks fishing here in good ol East Tennessee! I've been picking apart the Watauga River for the past 6 months trying to figure out the on slaught of hatches that river seems to have! I really wanted to fish the caddis hatch this year but seemed to miss out.

The other day while on the water we watched sporadic hatches of what appeared to be sulphurs coming off. Sizes ranging from about a 14 to a size 16 absolutely no smaller! I managed to snap a picture of one of these guys, but only after mashing his/her wing! I spent around 4 hours looking through Jason's site only coming up with the little yellow quill. I'm really confused guys. It has huge black eyes....ah forget it here's the pictures! This one would fit nicely on a size 14 TMC 100!

That veiny wing and the heavily segmented body is what's telling me it's not a sulphur!

I also managed to snap a few other pictures of some other specimans for you and a pic of a hydro for you all to marval at!

Here's that caddis!

Site Editor
"Bear Swamp," PA

Posts: 1681
GONZO on May 7, 2008May 7th, 2008, 4:41 am EDT

The yellow mayfly dun is a male heptageniid, the nymph is an Ephemerella nymph (probably one of the "sulphurs"), and the caddisfly pupa appears to be a hydropsychid.

PS--Welcome to the site!
JOHNW's profile picture
Chambersburg, PA

Posts: 452
JOHNW on May 7, 2008May 7th, 2008, 11:24 am EDT
It's good to hear the Watauga is doing so well insect wise. I'm curious as to what general area of the river your samples are from?
I was under the impression that the lower section (below the Old National Rayon in Elizabethton) was pretty limited for mayflies. I certainly hope that that old info is now incorrect and the insect life is fully rebounding from the fire.
"old habits are hard to kill once you have gray in your beard" -Old Red Barn
Taxon's profile picture
Site Editor
Plano, TX

Posts: 1311
Taxon on May 7, 2008May 7th, 2008, 11:48 am EDT

To supplement to Gonzo's family identification of your yellow mayfly dun, I believe it be Stenacron heterotarsale, now classified as Stenacron interpunctatum.
Best regards,
Roger Rohrbeck
Grants Pass, OR

Posts: 302
Creno on May 7, 2008May 7th, 2008, 12:48 pm EDT
Brett - if you still have the caddis specimen it can probably be identified to species since the black wingpads are quite developed. I would expect to be able to see obvious gill tufts if this is a hydropsychid. It looks to me like there are broad, flattened palps just under the head. (they could be the forelegs but they don't look right) If so this would probably be a brachycentrid. That would also explain what appear to be fairly thick antennae. Hydropsychids (except the Arctopsychinae) have fairly fine antennae, particularly at the tips.

Posts: 2
BrettHRomer on May 7, 2008May 7th, 2008, 2:36 pm EDT
Man! You all are awesome....I'd like to take all u guys fishing and pick ur brains! I'd love to be able to learn all this stuff, makes for a better tier! As far as the Watauga, it's pretty good...I wouldn't say a full rebound as of yet, but the fish are always willing to take what you give them in the lower section...Below persinger bridge all the way out! The river is absolutely chalked full of caddis!!!! Both cased and free living...I have one pattern that is absolutely killer for cased caddis on that river, a buddy and I dreamed it up after a couple of different patterns that wouldn't make the cut.

As for the caddis I no longer have that speciman! I need to get some bug balm! Anyone know any supplements?

Thanks again guys!
JOHNW's profile picture
Chambersburg, PA

Posts: 452
JOHNW on May 8, 2008May 8th, 2008, 10:26 am EDT
"....I'd like to take all u guys fishing and pick ur brains!"

Careful what you wish for with this crew.

As an aside have you started seeing any drakes on the mountain streams down that way? I'm thinking the hatch should be just about ready to pop.
"old habits are hard to kill once you have gray in your beard" -Old Red Barn

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