Header image
Enter a name
Lateral view of a Female Hexagenia limbata (Ephemeridae) (Hex) Mayfly Dun from the Namekagon River in Wisconsin
Hex Mayflies
Hexagenia limbata

The famous nocturnal Hex hatch of the Midwest (and a few other lucky locations) stirs to the surface mythically large brown trout that only touch streamers for the rest of the year.

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.

Stonefly Species Sierracapnia washoe (Little Snowflies)

Where & when

In 1 records from GBIF, adults of this species have been collected during February (100%).

Species Range


Source: Sierracapnia, A New Genus Of Capniidae (Plecoptera) From Western North America

Diagnosis. The males of all Sierracapnia species can be separated by their uniquely shaped and curved epiprocts (Figs 2, 6, 10, 14, 18, 29, 34). In addition, Sierracapnia washoe males are distinguished from all other species in the genus, except Sierracapnia mono and Sierracapnia shepardi, by having a wide median knob on tergum 7 (knob width 30 - 36 % of tergum width) (Figs. 23, 26, 30; Table 1). The dorsal membrane of the epiproct is dark in both Sierracapnia washoe and Sierracapnia shepardi, but is lightly colored in Sierracapnia mono and all other Sierracapnia species. Sierracapnia washoe and Sierracapnia shepardi are quite similar, sharing dark epiproct membranes, size and shape of tergal knobs, similarities in dorsal view of male terminalia, and nearly identical female subgenital plates. Yet, Sierracapnia washoe differs from Sierracapnia shepardi in the shape and proportions of the epiproct in lateral view. The epiproct of Sierracapnia washoe (Figs. 22, 29) is stouter (length 4.0 - 4.5 times depth versus 5.0 - 5.5 times depth for Sierracapnia shepardi), less reversely curved, and with longer arching dorsolateral horns than for Sierracapnia shepardi (Fig. 18; Table 1). When expanded, the eversible crest of Sierracapnia washoe (Fig. 31) is much larger than that which occurs in Sierracapnia shepardi.

The females of Sierracapnia washoe and Sierracapnia shepardi cannot be separated without associated males. Presently, the known distributions of these two species do not overlap. Sierracapnia shepardi has a wide north-south distribution in the central and southern Sierra Nevada, California, but has not been found in Nevada, while Sierracapnia washoe occurs in a north-south narrow band of western Nevada that extends 170 km south from the Granite Range near Gerlach to the mountains near Virginia City (Figs. 39, 40).

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.

Source: Sierracapnia, A New Genus Of Capniidae (Plecoptera) From Western North America

Male. Body length 3.7 - 6.3 mm (mean, 5.0 mm); wings macropterous; length of forewing 4.4 - 5.3 mm (mean, 4.8 mm); body color dark brown or black. Abdominal tergum 6 without median knobs (occasional individuals with median pair of slightly sclerotized bumps). Tergum 7 with a notched median knob (Figs 21, 23, 26, 27, 30; Table 1), knob width 30 - 36 % segment 7 width, depth of apical notch in knob variable. Tergum 8 lacking median knobs, with membranous central area dividing right and left sclerotized portions (Fig. 23). Tergum 9 with median pair of sclerotized knobs (Figs. 21, 23, 27, 29). Terga 7 and 9 knobs covered with dense rounded tubercles of conical sensilla; terga 6 - 9 with long stiff setae. Epiproct glabrous, except for caudal setae. Anterior half of epiproct surface covered with numerous shallow sensory pits, these less abundant or absent from epiproct neck and base. Epiproct laterally compressed and elongated; in lateral view, slightly convex dorsally and deeply convex ventrally, ventral edge of keel located between pair of tergum 9 knobs (Figs. 21, 23, 27, 29); epiproct width increases between narrow neck region and dorsolateral horn tips; epiproct extends forward to posterior margin of tergum 8; epiproct length 4.0 - 4.5 times maximum width and 4.0 - 4.5 times maximum depth; apical half of epiproct membrane is an eversible crest that is longitudinally folded or grooved and dark gray or black, except extreme tip lighter (Figs. 22, 24, 26, 28, 29); eversible crest may be greatly expanded in size at apex (Fig. 31) or not; epiproct apex broadly rounded, with short median posterior-projecting lobe (Figs. 24, 28). Dorsolateral horns arch above main body of epiproct, creating slight membranous gap between the sclerotized horns and main body; horns long, about 24 - 29 % epiproct length when viewed laterally; horn tips extend forward to 83 - 88 % of epiproct length (Figs. 22, 29; Table 1); horn tips slightly divergent; dorsolateral horns and epiproct body light brown, contrasting with dark membrane (Figs. 22, 24, 26, 28, 29).

Female. Body length 4.4 - 7.5 mm (mean, 5.9 mm), color dark brown or black; wings macropterous (Fig. 41); length of forewing 5.6 - 6.6 mm (mean, 6.0 mm); subgenital plate wide, heavily sclerotized, and black, sclerotization extends from the truncated posterior edge of sternum 8 onto sternum 7 (Figs. 25, 33). Sternum 7 sclerotization varies for individuals and populations; females from the Selenite Range have nearly full sclerotization, but most females from Storey County and Granite Range have a limited posterior band of sclerotization and a small lightly sclerotized area in mid segment.

Start a Discussion of Sierracapnia washoe

Stonefly Species Sierracapnia washoe (Little Snowflies)

Species Range
Troutnut.com is copyright © 2004-2024 (email Jason). privacy policy