Hatch activity of Strophopteryx fasciata follows T. navalis by about two weeks or so, late February early March. Hatches occur during the warmest time of the day on sunny afternoons.

   I've also observed these nymphs along with Taeniopteryx navalis drifting along in the surface film, and along with adults crawling along the snow covered river bank by the thousands, even as ice still partially covers the river. Once they begin hatching Fish can be found rising to them in years with an early spring or unseasonably warm weather as early as the first or second week in March, but most dry fly fishing doesn't become consistent until early or mid April.