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.H. & Kondratieff, B.C. (1983) Isoperla major, a new species of eastern Nearctic Isoperlinae (Plecoptera: Perlodidae). Annals of the Entomological Society of America 76, 270–273.