Nemoria mimosaria is recognizable by a distinct white spot on the first abdominal segment, an unmarked second segment (A2), and additional white coloration on the posterior segments of the abdomen. The wings are characterized by a distinct, fairly straight pm line on the forewing that shows a more convex curve near the costa. There is no red terminal line present, and the wing fringes are plain white. The area behind the interantennal fillet is green and does not exhibit any red or brownish collar.

Adult moth pictured above reared ex ovo; parent female collected from Hickory Run State Park, Carbon County, PA June 26, 2003. Larvae reared to adults on grey birch leaves, Betula populifolia.