Collected at a porch light. 39.5224, -78.3641

Steven Lingafelter at the Smithsonian made the ID based on microscopic inspection of the humeral punctation. Also note the more evenly distributed whitish pubescence (typically more patchy and yellow in E. atomarius). I only have three specimens of E. cortiphagus so I don't know if this would hold true for a larger series, but the background integument color seems to be intermediate between E. atomarius (dark chestnut brown) and E. rufulus (light reddish brown).