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.
Described by Nelson, C.R. & Baumann, R.W. (1987) New winter stoneflies of the genus Capnia with notes and an annotated checklist of the Capniidae of California (Plecoptera: Capniidae). Entomography 5, 485–521.