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

Blue-winged Olives
Baetis

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.

A small, old rock wing dam has created an excellent riffle and pool in this classic trout stream.

Stream photos

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Neoleptophlebia Mayfly Nymph Neoleptophlebia Mayfly Nymph

Dorsal view of a Neoleptophlebia (Leptophlebiidae) Mayfly Nymph from the Yakima River in Washington

Some characteristics from the microscope images for the tentative species id: The postero-lateral projections are found only on segment 9, not segment 8. Based on the key in Jacobus et al. (2014), it appears to key to Neoleptophlebia adoptiva or Neoleptophlebia heteronea, same as this specimen with pretty different abdominal markings. However, distinguishing between those calls for comparing the lengths of the second and third segment of the labial palp, and this one (like the other one) only seems to have two segments. So I'm stuck on them both. It's likely that the fact that they're immature nymphs stymies identification in some important way.

10 Recently Added Photos

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.

Finally got an October Caddis

By Troutnut on September 28th, 2017

I've been itching to photograph one of these for years and had an unexpected opportunity tonight when this one flew into a house full of aquatic scientists. It's the first insect I've collected for this site by chasing it around a kitchen with a tupperware container.

Closeup insects by Troutnut from the South Fork Snoqualmie River in Washington

Female Dicosmoecus gilvipes (October Caddis) Caddisfly Adult

16 Pictures

Female Dicosmoecus gilvipes (Limnephilidae) (October Caddis) Caddisfly Adult from the South Fork Snoqualmie River in Washington

I've been hoping to add a really good October Caddis to the photo collection here for years, but so far I had struck out on finding them on the river. Tonight, this one flew into the kitchen during a pizza party at a house along the river, and was quickly pointed out -- one of the perks of hanging out with other aquatic biologists! Maybe next year I can finally get a salmonfly on taco night or something.

Collected September 28, 2017 from the South Fork Snoqualmie River in Washington

Added by Troutnut on September 29, 2017

Collected September 28, 2017 from the South Fork Snoqualmie River in Washington and added by Troutnut on September 29, 2017

Comments / replies

Creno
Grants Pass, OR

Posts: 302

Creno on Sep 30, 2017September 30th, 2017, 1:23 pm EDT

Great Dicosmoecus pics Jason. I presume you kept it :-) The globular 9th I think I am seeing and the very dark, contrasting vein coloration are more typical of D. gilvipes. If you kept it take a good look at the spur count. D. atripes is 1-2-2 while D. gilvipes is 1-3-4. From what I can see the meso-tibia in several of the pics have 3 spurs. However, I am fairly sure fish don't count spurs :-) Have fun
creno

Troutnut

Administrator
Bellevue, WA

Posts: 2758

Troutnut on Sep 30, 2017September 30th, 2017, 2:24 pm EDT

Thanks Dave. I was wondering about that, after looking up the paper with the spur counts after taking the pictures. I thought from the pictures it looked more like 1-2-2, but your comment prompted me to go back and check it under the dissecting microscope. It's 1-3-4, clear as day. I just don't have as good an eye for spurs versus those smaller spikes on the legs in the photos, but the difference was really obvious under the scope.

Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist

Wiflyfisher

Wisconsin

Posts: 622

Wiflyfisher on Oct 6, 2017October 6th, 2017, 2:47 am EDT

Jason, excellent!

Now that WI has an extended inland trout season I have been on the hunt for the elusive Great Autumn Brown Sedges (Pycnopsyche), especially the pupae. So far no success.

John S.
https://WiFlyFisher.com