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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 Amphizoa (Amphizoidae) Beetle Larva from Sears Creek in Washington
This is the first of it's family I've seen, collected from a tiny, fishless stream in the Cascades. The three species of this genus all live in the Northwest and are predators that primarily eat stonefly nymphs Merritt R.W., Cummins, K.W., and Berg, M.B. (2019).
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.

Female Hesperoperla pacifica (Golden Stone) Stonefly Adult Pictures

I collected this specimen as a nymph and had it in line to be photographed, but it emerged inside my holding container before I got the chance. However, I was able to get some interesting photos of the very freshly-emerged adult that really demonstrate how strikingly colors can change within a few short hours after emergence. The before-and-after pictures are combined here under a single specimen since they portray the same individual at different times within the same stage.

Based on the identification of another specimen from the same date/site, I'm calling this Hesperoperla pacifica.

Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Lateral view of a Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Ruler view of a Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana The smallest ruler marks are 1 mm.
Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana
Ventral view of a Female Hesperoperla pacifica (Perlidae) (Golden Stone) Stonefly Adult from the Gallatin River in Montana

This stonefly was collected from the Gallatin River in Montana on July 2nd, 2019 and added to Troutnut.com by Troutnut on July 18th, 2019.


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Female Hesperoperla pacifica (Golden Stone) Stonefly Adult Pictures

Collection details
Location: Gallatin River, Montana
Date: July 2nd, 2019
Added to site: July 18th, 2019
Author: Troutnut
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