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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 Sweltsa (Chloroperlidae) (Sallfly) Stonefly Nymph from the Yakima River in Washington
This species was fairly abundant in a February sample of the upper Yakima.
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.

Leskorcala has attached these 5 pictures to aid in identification. The message is below.
Posts: 16
Leskorcala on Aug 24, 2020August 24th, 2020, 3:46 pm EDT
hello, In late July and first week of august I spotted many 2 winged mayflies spinners on the walls of my house (I live about 20 yards from the edge of Bitterroot river, MT ) All of the spinner adults had 2 tails
I have narrowed down by size, tail numbers,emergence to family Heptageniidea , Genus Empeours I believe its E. albertae species. The Slate cream dun
Hope someone can conform this for me. I am in process doing year long project identify all teh major hatches on my home river, hope to get it done next year.
Martinlf's profile picture
Palmyra PA

Posts: 3047
Martinlf on Aug 26, 2020August 26th, 2020, 12:49 pm EDT
When Roger sees this he'll probably give you an ID.
"He spread them a yard and a half. 'And every one that got away is this big.'"

--Fred Chappell
Taxon's profile picture
Site Editor
Plano, TX

Posts: 1311
Taxon on Aug 26, 2020August 26th, 2020, 4:25 pm EDT
Well Louis, would if I could, but frankly, I'm thoroughly stumped.
Best regards,
Roger Rohrbeck
Martinlf's profile picture
Palmyra PA

Posts: 3047
Martinlf on Aug 27, 2020August 27th, 2020, 4:34 pm EDT
"He spread them a yard and a half. 'And every one that got away is this big.'"

--Fred Chappell
Troutnut's profile picture
Bellevue, WA

Posts: 2758
Troutnut on Sep 3, 2020September 3rd, 2020, 6:35 pm EDT
Hi Les,

Very nice pictures!

I think this probably is Epeorus. From the fourth picture, it looks like the first two tarsal segments are approximately the same length, which usually points to that genus.

I don't think the species is albertae, unless I have misidentified the specimens labeled as albertae on this site, including this one most recently. The coloration of the abdomen is very different, and I seem to recall the spots on the femora are a key feature of albertae as well.

Unfortunately I'm not sure what species it is, as I don't have my ID resources with me at the moment on a trip.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
Posts: 16
Leskorcala on Sep 10, 2020September 10th, 2020, 5:08 pm EDT
Thanks Jason for your feedback. this is very popular hatch on my home water , lot of anglers would call them PMD but the 2 tail is easy giveaway
sorry in my original post I said 2 winged mayfly ( I was referring to 2 tail mayfly ) anyway , I can see now looking at some references images where spots on femora are absent on this mayfly.

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