Like all other Stenonema, ithaca nymphs are clingers preferring fast riffles. Male duns display large black eyes, female duns display smaller black eyes. Almost all Stenonema have black eyes that change color after exposure to light. Note the pictured males eyes have changed color, the insert showing a freshly hatched female with black eyes, and a female after exposure to light with lighter colored eyes. Stenonema never hatch in great numbers, but will hatch sporadically though the day on cooler cloudy days. The majority of cahill hatches are concentrated on the lower east, west branch, and the main stem. It's rare to find Stenonema ithaca in any number on the upper sections of the east, and west branch. Ithaca duns range in color from Cream to Pale Tanish Yellow. Stenonema ithaca are almost identical to Stenacron canadense except for their larger size.

   Mature nymph species identification - S. ithaca, Tails rigid, and held apart, threadlike gill on abdominal segment 7, abdominal segments 1 - 6 gills truncate at apex, lateral spines on abdominal segments 6 - or 7 - 9, sternites 4 - or 5 - 8 has a brown median cross stripe. Modified from - Burks - The Mayflies, or Ephemeroptera, of Illinois - 1909 reprinted 1953.