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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.

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.
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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