Isoperla namata Frison .

States bordering Illinois, except Iowa and Wisconsin, support populations of I. namata (Frison 1942; Poulton & Stewart 1991; DeWalt et al. 2010). As noted above, there is some doubt about the taxonomic boundary and distribution of this species. A single Illinois female in the INHS collection has been tentatively identified as I. namata by S. W. Szczytko. A male paratype from Indiana was re-examined and the aedeagus everted revealing two basal spurs and confirming the existence of this species in the state.

IL, Adams Co., Quincy, [39.935, - 91.416], 6/3/1950, J.P. Nielsen, ♀ (INHS); IN, Owen Co., McCormick's Creek, McCormick’s Creek State Park, [39.2906, -86.7174], 4/16/1938, T.H. Frison, ♂ (reared) (INHS) .