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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.

Lateral view of a Clostoeca disjuncta (Limnephilidae) (Northern Caddisfly) Caddisfly Larva from the Yakima River in Washington
This one was surprisingly straightforward to identify. The lack of a sclerite at the base of the lateral hump narrows the field quite a bit, and the other options followed fairly obvious characteristics to Clostoeca, which only has one species, Clostoeca disjuncta.
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.

CalebBoyle has attached these 2 pictures to aid in identification. The message is below.
Charlotte, NC

Posts: 11
CalebBoyle on May 23, 2007May 23rd, 2007, 2:27 pm EDT
Hi guys,

I found this female mayfly near where I live and wanted to see what you all thought about it. It was found in gaston county (near Charlotte) in North Carolina. When I first glanced at it I thought it must be some kind of drake, but quickly realized it couldn't be. There are only 2 tails and this monster is 36-37mm long. I have never heard of Hexagenia in North Carolina, but isn't this a H. limbata? If so what records are there for NC hatches and how common are they? Most of the pictures that I have seen of limbata have darker markings on the abdomen, but then what other mayfly is this size other than a Litobrancha recurvata?

Caleb Boyle
Taxon's profile picture
Site Editor
Plano, TX

Posts: 1311
Taxon on May 23, 2007May 23rd, 2007, 3:03 pm EDT
Nice photos, Caleb. You have (3) Hexagenia species in N. Carolina, H. atrocaudata, H. bilineata, and H. limbata. However, given its size and date of emergence, it is almost certainly H. limbata. Incidentally, notice the characteristic vestigal terminal filament! That is one I've been saving for you, Gonzo.
Best regards,
Roger Rohrbeck
Troutnut's profile picture
Bellevue, WA

Posts: 2758
Troutnut on May 23, 2007May 23rd, 2007, 3:20 pm EDT
It's H. limbata. That's a widely variable species, and back in the 1940s it was actually broken into about 6 sub-species with different looks and geographic ranges. The sub-species aren't considered valid anymore (it's all just one undivided species now, I think) but the point is that H. limbata comes in many flavors.

Somebody recently emailed me asking me to identify one from Texas, too.
Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist
Site Editor
"Bear Swamp," PA

Posts: 1681
GONZO on May 23, 2007May 23rd, 2007, 4:08 pm EDT
Roger--Thanks for the terminal filament reference. You've been saving that one for a while!

Caleb--Beautiful specimen! The variability in color/markings that Jason mentions always amazes me when I view specimens of this transcontinental species.
Charlotte, NC

Posts: 11
CalebBoyle on May 24, 2007May 24th, 2007, 8:43 am EDT
Thanks guys for the confirmations-- I had just never heard about limbata this far south. I agree Gonzo, I have seen some photos of color variations that are really different.


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