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.

Firehole River Sunset

From the Firehole River in Wyoming

Stream photos

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Holocentropus Caddisfly Larva Holocentropus Caddisfly Larva

Dorsal view of a Holocentropus (Polycentropodidae) Caddisfly Larva from the Yakima River in Washington

This one seems to tentatively key to Holocentropus, although I can't make out the anal spines in Couplet 7 of the Key to Genera of Polycentropodidae Larvae nor the dark bands in Couplet 4 of the Key to Genera of Polycentropodidae Larvae, making me wonder if I went wrong somewhere in keying it out. I don't see where that could have happened, though. It might also be that it's a very immature larva and doesn't possess all the identifying characteristics in the key yet. If Holocentropus is correct, then Holocentropus flavus and Holocentropus interruptus are the two likely possibilities based on range, but I was not able to find a description of their larvae.

11 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.

Male Eurylophella minimella (Chocolate Dun) Mayfly Spinner Pictures

The genus ID on this specimen is confident but species is very tentative, based on the tentative ID of a seemingly-identical specimen from a nearby river a few days apart.

Lateral view of a Male Eurylophella minimella (Ephemerellidae) (Chocolate Dun) Mayfly Spinner from the Namekagon River in Wisconsin

Male Eurylophella minimella (Ephemerellidae) (Chocolate Dun) Mayfly Spinner from the Namekagon River in Wisconsin

Ventral view of a Male Eurylophella minimella (Ephemerellidae) (Chocolate Dun) Mayfly Spinner from the Namekagon River in Wisconsin

Dorsal view of a Male Eurylophella minimella (Ephemerellidae) (Chocolate Dun) Mayfly Spinner from the Namekagon River in Wisconsin

This mayfly was collected from the Namekagon River in Wisconsin on June 3rd, 2005 and added to Troutnut.com by Troutnut on May 24th, 2006.

Discussions of this Spinner

Not invaria

2 replies

Posted by GONZO on May 24, 2009

Last reply on May 24, 2009 by GONZO

This spinner is Eurylophella rather than E. invaria. The long 9th abdominal segment of Eurylophella is often the easiest way to avoid confusing the duns and spinners with Ephemerella. The claspers and genitalia of this male are also representative of Eurylophella.

Invaria Spinners

10 replies

Posted by Martinlf on Aug 9, 2007

Last reply on Aug 10, 2007 by JAD

These photos show a darker invaria spinner than I'm used to seeing. I know color varies a good bit in invaria nymphs and duns, so I suppose color variation is pretty wide with the spinners also, correct?

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