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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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Millcreek has attached these 2 pictures to aid in identification. The message is below.
Healdsburg, CA

Posts: 344
Millcreek on Nov 26, 2016November 26th, 2016, 11:25 am EST
These nymphs were identified using "The Isoperla of California (Plecoptera; Perlodidae); Larval Descriptions and a Key to 17 Western Nearctic Species" by John B. Sandberg. http://www2.pms-lj.si/illiesia/papers/Illiesia07-22.pdf

The nymphs are approximately 7mm in length excluding cerci and antennae. This is less than the size given in the article but these are early instars.

They were collected on November 24th, 2016 from the Russian River. They were collected in about 16 inches of water in glides with a bottom of gravel and cobble.
"If we knew what it was we were doing, it would not be called research, would it?"
-Albert Einstein
PaulRoberts's profile picture

Posts: 1776
PaulRoberts on Nov 28, 2016November 28th, 2016, 3:10 am EST
Very pretty critters!
Jmd123's profile picture
Oscoda, MI

Posts: 2474
Jmd123 on Nov 28, 2016November 28th, 2016, 10:13 am EST
I agree with Paul - stoneflies seem to be the most colorful of the aquatic nymphs. Of course, somebody on here (Eric or Roger?) will show me a colorful mayfly nymph or caddis larva I wasn't aware of...

No matter how big the one you just caught is, there's always a bigger one out there somewhere...
Oldredbarn's profile picture
Novi, MI

Posts: 2600
Oldredbarn on Dec 5, 2016December 5th, 2016, 1:32 pm EST
Yes...to all, but to me its all about camouflage! It is incredible how gaudy they may look in a petri dish, but they probably disappear on the bottom of the stream...

A month or so back I was watching ducks on a forested pond out by Jackson Michigan. It was chaos! There were geese and ducks everywhere...Migration was in its early stages.

I had my binocs and I was scanning the surface and there was a male Wood duck in all his glory...One of natures show-offs. He had nearly disappeared on the surface as he glided across the pond trying to get away from me. Somehow his coloration blended in with the reflections on the pond...Autumn leaves etc...

It was an eye opener for me.

Maybe he looks just right to the females, or maybe that color combo helps him blend in and survive. Just right for a bird that hangs out in a forest.
"Even when my best efforts fail it's a satisfying challenge, and that, after all, is the essence of fly fishing." -Chauncy Lively

"Envy not the man who lives beside the river, but the man the river flows through." Joseph T Heywood
PaulRoberts's profile picture

Posts: 1776
PaulRoberts on Dec 6, 2016December 6th, 2016, 3:05 am EST
Those little buggers are cute! I bet their mama's and papa's think so too. And I bet the trout even give em a pass. How could they not? In fact I've never caught a trout on a super-realistic baby Isoerla imitation. Don't even carry one. Bet you don't either.

I bet it's the same for male woodducks. Ever seen a goshawk snatch one out of the air in front of you? I haven't. Bet you haven't either.

Actually, it's probably not about camo, or at least mostly so. It's all show, and likely at some higher risk. The hens show us what a woodduck, or mallard, looks like when it needs camo. Note too that drakes lose some of that finery outside the breeding season. Woodies are spooky things though, and at a distance they all look sooty and fly "under the radar" -low and fast and prefer to stick to cover. One really has to get close to fully appreciate a male woody.

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