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Lateral view of a Male Baetis (Baetidae) (Blue-Winged Olive) Mayfly Dun from Mystery Creek #43 in New York
Blue-winged Olives

Tiny Baetis mayflies are perhaps the most commonly encountered and imitated by anglers on all American trout streams due to their great abundance, widespread distribution, and trout-friendly emergence habits.

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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Posts: 2
Crossb1111 on Sep 14, 2010September 14th, 2010, 9:23 am EDT
Just wondering if anyone might have any suggestions as to what hatches may be coming off of the rile river this upcoming weekend (sept 18) and what flies they might suggest. Thanks for any input.
Oldredbarn's profile picture
Novi, MI

Posts: 2600
Oldredbarn on Sep 14, 2010September 14th, 2010, 10:57 am EDT

Just got back from the Au Sable this past weekend...I saw the small Black Dancer Caddis #18-20...There was a tiny Baetis...Maybe the pygmalus #22 or so...We saw a few Cinammon Caddis #14 and what I thought were a size 14 Light Cahill but I never caught one to check it out and I wouldn't count on this one (must be the last of them) though I caught a couple small fish on a lighter bodied Borchers...(?)

Don't forget ants, beetles, and some small streamers...

There may be a few Iso's left but I never spotted one and the late season Paraleptophlebia debilis...Small Slate Mahogany #16-18 though I didn't see any and the larger later Baetis tricaudatus & heimalis though I didn't positively spot any of these either.

The hatch activity I watched was very sparse...When we were wading the South Branch during the clean-up we had a really nice fish feeding in a slick...Wouldn't you know it...When no one was carrying a rod!

Sorry if some of these bugs' names don't match the newer names ascribed to them...I'm at work and heading home for the evening and just rattling this off from memory...an old farts memory...

"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
Konchu's profile picture
Site Editor

Posts: 498
Konchu on Sep 14, 2010September 14th, 2010, 12:51 pm EDT
I'm not aware of much fall/late summer activity on the Rifle. I collected aquatic insects there several years back at Omer. The only three significant (not in scientific terms, thank you) mayflies over the course of a year that I remember from that stream are Ephemerella subvaria, E. needhami, and Neoephemera bicolor. BTW, if anyone ever collects any N. bicolor there, I'd really, REALLY like to see them! It's an interesting stream.
Jmd123's profile picture
Oscoda, MI

Posts: 2474
Jmd123 on Sep 14, 2010September 14th, 2010, 1:15 pm EDT
Caddis flies!!!! They are on the river until early October. Try white, cream, light tan, and light gray, in sizes 12-14. I fished the Rifle hard (4-5 nights/week) for four seasons (1998-2001) and was delighted to find that the caddis hatches keep right on coming until summer is well past over. And, the fish do respond...You will see them skimming over the water as the sun goes down.

Keep some attractors handy as well - my favorites are White and Royal Wulffs in sizes 10-12. Also, hoppers for daylight - I used to use a Joe's Hopper in size 10 - and make some into crickets (all-black with gray wings) and katydids (all-green) for evening into darkness...

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

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