The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
In 52 records from GBIF, adults of this genus have mostly been collected during June (60%), May (33%), and July (6%).
In 33 records from GBIF, this genus has been collected at elevations ranging from 20 to 5614 ft, with an average (median) of 2356 ft.
A hundred or more cases might be stacked in layers on the underside of a particular rock. When the emergence period begins the pupae pop continually from this area. They escape from the cocoon and wash out from under the rock, creating a food line for trout on the downstream side of the pupation site. During the peak evening hours the emerging pupae may create feeding situations in only a small part of the stream. They attract trout into these prime zones (which fly fishermen can find beforehand by searching for the clusters of pupae).
Time of day: Evening
Diet: Omnivorous
Substrate: Silt, sand, or gravel
Environmental tolerance: Prefers cool streams
Shelter type: Horn-shaped sand and gravel cases