Taeniopteryx navalis, is the most likely insect to produce enough rising fish for fishing dry flies early in the season. T. navalis begins hatching in large numbers in late February early March. Hatches occur during the warmest time of the day on sunny afternoons.

   I've observed these nymphs along with Strophopteryx fasciata 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.

   Taeniopteryx are much more tolerant of water conditions than other Stonefly nymphs, and are found in a wide variety of environments from clear cool streams, to slower warm silt bottomed rivers.