The giant Salmonflies of the Western mountains are legendary for their proclivity to elicit consistent dry-fly action and ferocious strikes.
In 6 records from GBIF, adults of this species have been collected during June (67%) and July (33%).
To determine whether a specimen of Agnetina belongs to Agnetina flavescens, use the Key to Species of Agnetina Nymphs or Key to Species of Agnetina Adults.