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Artistic view of a Male Pteronarcys californica (Pteronarcyidae) (Giant Salmonfly) Stonefly Adult from the Gallatin River in Montana
Pteronarcys californica

The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.

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.
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Mayfly Species Callibaetis montanus (Speckled Duns)

Where & when

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

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.

Female Spinner

Body length: 6 mm
Wing length: 8 mm

A brownish yellow species; cross veins of fore wing few in number; marginal intercalaries occur singly; male not known.

“Body discolored; notum testaceous, irrorated on each side with brown ochre, and traversed lengthwise by a median brown-ochreous stripe intersected by a light yellowish line” (Eaton). Legs “somewhat of a dull light Vandyke brownish-grey, stippled or irrorated minutely and densely in the femora with very light burnt umber brown”; tarsal joinings similar in color; distal joints of the tarsi darkened, claws black. Wings vitreous; cross veins of fore wing few in number, intercalaries single. Costal vitta light raw-umber brown in color, occupying the costal, subcostal and “next adjoining spaces,” and widened at the base of the wing; this band varies in intensity apically and in the basal costal space. Veins similar in color, except the basal costal cross veins, which are whitish. 6 or 7 cross veins before the bulla; beyond it “about 7 rudimentary and 7 well-defined simple and almost straight” cross veins. Tails white; joinings and basal joints yellowish.

Start a Discussion of Callibaetis montanus


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

Mayfly Species Callibaetis montanus (Speckled Duns)

Species Range
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