Isoperla marlynia (Needham & Claassen) .

This riverine species in known from the Great Plains east to New Jersey and north to the Canadian Maritime Provinces (DeWalt et al. 2010). The only records from Indiana pertain to historical collections from the lower White River between 1936 and 1940. In Illinois, this species is known only from the Rock River at Rock Island, taken between 1928 and 1932. A single exuvium was recently collected from the Pecatonica River near the Wisconsin border, confirming its continued presence in Illinois.

IL, Stephenson Co., Pecatonica River, Winslow at Winslow Rd., 42.49302, -89.78979, 6/23/2010, R.E. DeWalt, E.W. Hernandez, M.M. Brown, exuvium (INHS) .