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.

Waterfalls over smooth bedrock above Titcomb Lakes

From Titcomb Basin in Wyoming

Stream photos

Featured on the forum

Re: Trico emergers
In the Mayfly Genus Tricorythodes by Bwoklink (Martinlf replied)

Re: Trico Tips
In the Mayfly Genus Tricorythodes by Martinlf

Re: UV spectrum and trout
In General Discussion by Martinlf

Re: closing the gender gap in flyfishing
In General Discussion by Konchu (Smallflyguy replied)

Re: Fishing Kupa River, Slovenia
In Fishing Reports by Slocum (Fish1 replied)

Coleoptera (Beetle) Insect Larva Coleoptera (Beetle) Insect Larva

Lateral view of a Coleoptera (Beetle) Insect Larva from Sears Creek in Washington

6 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.

Identification: Key to Species of Agnetina Adults, Couplet 2

Couplet 2
Full Key at a Glance

Adapted from Stark et al (1986)

Option 1	Option 2
Ventral margin of femora dark forming mesal yellow window Anterior view of femur of Agnetina capitata. Figure source: Stark et al (1986)	Ventral margin of femora light Anterior view of femur of Agnetina flavescens. Figure source: Stark et al (1986)
Apical portion of male hemitergal process long and sinuate, toe bluntly rounded Lateral view of hemitergal process of male Agnetina capitata. Figure source: Stark et al (1986)	Swollen area of male hemitergal process adjacent to foot obscuring ankle area Lateral view of hemitergal process of male Agnetina flavescens. Figure source: Stark et al (1986)
Dark pirgment areas on female sterna 8 and 9 large quadrangular Sterna 8 and 9 of female Agnetina capitata. Figure source: Stark et al (1986)	Dark pigment areas of female sterna 8 and 9 not quadrangular Sterna 8 and 9 of female Agnetina flavescens. Figure source: Stark et al (1986)

source	source
2 Example Specimens Male Agnetina capitata (Golden Stone) Stonefly Adult Male Agnetina capitata (Golden Stone) Stonefly Adult 11 Pictures Male Agnetina capitata (Golden Stone) Stonefly Adult Male Agnetina capitata (Golden Stone) Stonefly Adult This stonefly emerged in my aquarium, and unfortunately I severely damaged its wings just trying to catch it. It's still an interesting specimen, especially since I was able to also photograph the nymphal shuck it emerged from. I was surprised by just how light it was shortly after emerging. I photographed it a couple days later when it had darkened considerably; it was a pale, almost pastel yellow at first. 9 Pictures
Agnetina capitata	Agnetina flavescens

Adapted from Stark et al (1986)

The current couplet is highlighted with darker colors and a icon, and couplets leading to this point have a icon.

Couplet 1

Leads to Agnetina annulipes:

Femora transversely banded
Male hemitergal process foot-shaped with long slender ankle and toe
Female subgenital plate truncate, dark pigment covers sternum 8 in continuous mesal band

Agnetina annulipes

Leads to Couplet 2: