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.
Size 11 mm. Prior to this photo the specimen dropped its large egg mass that was a very dark (almost black) olive sphere almost twice the diameter of the abdomen. Notice the abdomen visible through the wings is both thickened and shortened post egg drop.