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.
These species hatch in or near the surface in calm water. Emergence is quite fast, but the duns may drift a while.
Egg-Laying behavior
Time of day: Dusk
Habitat: Riffles
The female spinners oviposit by flying over the water and dropping down to the surface to release some eggs, then taking off to do it again. They eventually fall spent.