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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.

Dorsal view of a Grammotaulius betteni (Limnephilidae) (Northern Caddisfly) Caddisfly Larva from the Yakima River in Washington
This is a striking caddis larva with an interesting color pattern on the head. Here are some characteristics I was able to see under the microscope, but could not easily expose for a picture:
- The prosternal horn is present.
- The mandible is clearly toothed, not formed into a uniform scraper blade.
- The seems to be only 2 major setae on the ventral edge of the hind femur.
- Chloride epithelia seem to be absent from the dorsal side of any abdominal segments.
Based on these characteristics and the ones more easily visible from the pictures, this seems to be Grammotaulius. The key's description of the case is spot-on: "Case cylindrical, made of longitudinally arranged sedge or similar leaves," as is the description of the markings on the head, "Dorsum of head light brownish yellow with numerous discrete, small, dark spots." The spot pattern on the head is a very good match to figure 19.312 of Merritt R.W., Cummins, K.W., and Berg, M.B. (2019). The species ID is based on Grammotaulius betteni being the only species of this genus known in Washington state.
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 Rhithrogena Mayfly Spinner Pictures

I'm very tentatively (see the connected forum thread) sticking this mayfly in Rhithrogena for now.

Female Rhithrogena (Heptageniidae) Mayfly Spinner from the West Branch of the Delaware River in New York
Female Rhithrogena (Heptageniidae) Mayfly Spinner from the West Branch of the Delaware River in New York
Female Rhithrogena (Heptageniidae) Mayfly Spinner from the West Branch of the Delaware River in New York
Ventral view of a Female Rhithrogena (Heptageniidae) Mayfly Spinner from the West Branch of the Delaware River in New York
Lateral view of a Female Rhithrogena (Heptageniidae) Mayfly Spinner from the West Branch of the Delaware River in New York
Female Rhithrogena (Heptageniidae) Mayfly Spinner from the West Branch of the Delaware River in New York
This image is overly enhanced to better show the structure of the veins.

Female Rhithrogena (Heptageniidae) Mayfly Spinner from the West Branch of the Delaware River in New York
Dorsal view of a Female Rhithrogena (Heptageniidae) Mayfly Spinner from the West Branch of the Delaware River in New York
Ruler view of a Female Rhithrogena (Heptageniidae) Mayfly Spinner from the West Branch of the Delaware River in New York The smallest ruler marks are 1 mm.

This mayfly was collected from the West Branch of the Delaware River in New York on June 7th, 2007 and added to Troutnut.com by Troutnut on June 8th, 2007.

Discussions of this Spinner

What genus is this Heptageniid?
4 replies
Posted by Troutnut on Jun 8, 2007
Last reply on Feb 1, 2009 by Taxon
I didn't even recognize it as a member of that family at first, but it seems to be the only option. The hind tarsus is distinctly 5-segmented, which I verified under the microscope because you can't see it very well on my photos. However, I because it's a female spinner I can't key it to genus using the Merrit & Cummins keys. Does anyone just recognize it?

I found it drifting, nearly dead on the surface at about 5pm on a hot afternoon.

Start a Discussion of Spinner

References

Female Rhithrogena Mayfly Spinner Pictures

Collection details
Location: West Branch of the Delaware River, New York
Date: June 7th, 2007
Added to site: June 8th, 2007
Author: Troutnut
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