Isoperla similis (Hagen, 1861)

was reported from Maryland by Duffield & Nelson (1990) (Fig. 27). This species has since been redefined by Szczytko & Kondratieff (2015) and is now considered a species found mainly along the Piedmont and Atlantic Coastal Plain regions. Szczytko & Kondratieff (2015) included I. similis from Maryland based on a single female from the Blue Ridge Physiographic Province (Fig. 27).