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 Ricker, W.E. & Ross, H.H. (1975) Synopsis of the Brachypterinae (Insecta: Plecoptera: Taeniopterygidae). Canadian Journal of Zoology 53, 132–153.