The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
In 25 records from GBIF, adults of this species have mostly been collected during July (44%), August (40%), and June (12%).
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.
This species has a pale abdomen shaded with brown; it is close to Paraleptophlebia guttata.
Head and thorax deep blackish, the pleura tinged with brown. Legs whitish. Fore femora tinged with brown throughout; middle and hind femora brown-tinged apically, with the knee brown. Wings hyaline, veins pale. Thorax deep red-brown. Legs pale amber. Longitudinal veins faintly amber-colored.
Abdomen of male whitish hyaline on segments 2-6 and the anterior portion of 7; tergite 2 with considerable dark shading. Apical segments opaque, deep chocolate brown. A short black transverse streak on the postero-lateral corner of segments 2-6, which often has some slight brown suffusion anterior to it, distinguishes this species from P. guttata; in the latter, black lateral dots are present instead of the black streaks. Tails and forceps whitish, faintly brown-tinged at the base. Penes very similar to guttata, but convergent, not divergent apically; the beak-like lateral projections are somewhat shorter and the ribbon-like reflexed spurs longer. (See fig. 133)The subanal plate with a deep narrow U-shaped apical excavation.