Diplectrona modesta Banks, 1908 (Trichoptera: Hydropsychidae) is a common species of caddisfly found across eastern North America and often used in water quality biomonitoring studies.  The variation in habitat choice and morphology, as noted by many taxonomists, has led to suggestions that D. modesta may be a species complex consisting of two or more species.  This study examined mitochondrial COI and nuclear ribosomal large subunit (28S) gene sequences from populations of D. modesta in the eastern United States. The variation found suggests that D. modesta consists of more than one species.