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.

Stream photos

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Limnephilus (Summer Flier Sedge) Caddisfly Larva Limnephilus (Summer Flier Sedge) Caddisfly Larva

Case view of a Limnephilus (Limnephilidae) (Summer Flier Sedge) Caddisfly Larva from the Yakima River in Washington

This seems to be a young larva of Limnephilus. Although not clear in the picture, several ventral abdominal segments have chloride epithelia.

7 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.

Mayfly Species Ameletus dissitus (Brown Duns)

Where & when

In 4 records from GBIF, adults of this species have been collected during June (50%), July (25%), and April (25%).

Species Range

source

Map of specific collection sites

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

Described in Needham et al (1935)

Body length: 10-12.5 mm
Wing length: 10-12.5 mm

A clear-winged species, in which the wings are faintly tinged with greenish grey. Body yellowish.

Head brownish. Thorax brown. Pronotum and posterior portion of metanotum blackish. Fore leg blackish brown; middle and hind legs yellowish to yellowish brown, the femora tinged with darker brown. Wings hyaline, very faintly tinged with greenish grey. Venation blackish brown. Stigmatic cross veins strongly anastomosed.

Abdomen bright yellowish to yellowish brown. Posterior margins of tergites 2-8 and the postero-lateral angles, blackish brown. Tergites 9 and 10 similarly marked, but somewhat darker in color. Sternites somewhat lighter in color than the tergites, “and seemingly marked each with a light pitch-brown blotch at the base in the middle”’ (Eaton). Forceps base light yellowish. Forceps blackish. Tails dark brown, joinings opaque. Genitalia as in fig. 118.

Start a Discussion of Ameletus dissitus

References

Needham, James G., Jay R. Traver, and Yin-Chi Hsu. 1935. The Biology of Mayflies. Comstock Publishing Company, Inc.