Artistic view of a Male Pteronarcys californica (Pteronarcyidae) (Giant Salmonfly) Stonefly Adult from the Gallatin River in Montana

Salmonflies
Pteronarcys californica

The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.

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.

Link to pictures of H. culacantha

This topic is about the Mayfly Species Heptagenia culacantha

This species is not known to be important to anglers. It is noteworthy for its relatively recent discovery, its large size, and the striking coloration of its nymphs and duns. They are sometimes called Tiger Mayflies.

This is the largest species of Heptagenia on the continent, and it's also one of the largest in the entire Heptageniidae family. Nymphs and adult females have been collected with bodies up to a size of 19.5mm, a little over 3/4" long.

Example specimens

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Male Heptagenia culacantha Mayfly Spinner

Male Heptagenia culacantha (Heptageniidae) Mayfly Spinner from the Susquehanna River in Pennsylvania

This photo was provided by guide Eric Naguski along with the following comments, "I took this photo just upstream of Three Mile Island on the east shore of the Susquehanna River just below where the Swatara Creek enters. The Susquehanna is not an easy river to sample for bugs in my opinion. It is very large and pushes a lot of water. Especially in the spring when you would collect mature culacantha nymphs. And I don't believe that there are a ton of these Heptageniids around. Also the people who are doing most of the sampling like myself are doing so for water quality monitoring work so they only take the specimens down to genus-level taxonomy".

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Male Heptagenia culacantha Mayfly Dun

Photo credit: Hyun Kounne

Dorsal view of a Male Heptagenia culacantha (Heptageniidae) Mayfly Dun from the Delaware River in New York

Hyun Kounne generously provided photos of the striking, hard-to-find Heptagenia culacantha from the mainstem Delaware River. She mentioned it was one of maybe half a dozen she saw on the water that day.

Troutnut

Administrator
Bellevue, WA

Posts: 2758

Troutnut on Oct 20, 2006October 20th, 2006, 2:35 pm EDT

Many thanks to user Softhackle for digging up this link. I knew about the thread from back when it started, but I wasn't able to find it when I went back to look last night. Good work!

Fly Fisherman Magazine forum topic with two pictures of a H. culacantha dun.

I've added the species to the "live" part of the database and put up a rudimentary page where I can compile any more information we find.

Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist

Americom8
west chester

Posts: 1

Americom8 on Oct 4, 2007October 4th, 2007, 5:46 am EDT

They are infested in WestChester PA.. Try 1100 West Chester Pike, an apt complex. Infested

Troutnut

Administrator
Bellevue, WA

Posts: 2758

Troutnut on Oct 4, 2007October 4th, 2007, 10:18 am EDT

I would think the infestation would be a different species.

Jason Neuswanger, Ph.D.
Troutnut and salmonid ecologist