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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.

Mayfly Species Isonychia campestris (Slate Drakes)

Where & when

Time of year : September and October

In 4 records from GBIF, adults of this species have been collected during July (50%) and August (50%).

Species Range

Physical description

Most physical descriptions on Troutnut are direct or slightly edited quotes from the original scientific sources describing or updating the species, although there may be errors in copying them to this website. Such descriptions aren't always definitive, because species often turn out to be more variable than the original describers observed. In some cases, only a single specimen was described! However, they are useful starting points.

Male Spinner

Body length: 9-10? mm
Wing length: 9-11? mm

Somewhat paler than Isonychia sicca; venation dark.

Head of female pale yellowish, with traces, more or less distinct, of brown submedian stripes on the vertex and occiput. Blackish brown spot between eye and lateral ocellus, but no dark mark in corners of occiput. Thorax of male light brown, shaded somewhat with reddish and blackish brown on the scutellum. Fore leg entirely reddish black, tarsi somewhat paler. Middle and hind legs dull yellow, with slight red shading on the femora. Wings with fine veins, all dark-tinged.

Abdomen dorsally dull brown tinged with red, shaded laterally with deeper brown in the form of poorly defined dark patches; lateral margin pale brown. Light brown ventrally, rather paler than the dorsum. Penes similar in form to those of sicca.

Female Spinner

Head of female pale yellowish, with traces, more or less distinct, of brown submedian stripes on the vertex and occiput. Subanal plate of female rather deeply excavated apically, its outer angles acute.


Start a Discussion of Isonychia campestris

References

Mayfly Species Isonychia campestris (Slate Drakes)

Taxonomy
Species Range
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