A new species of armored scale, Hemiberlesia neodiffinis Miller and Davidson, is described and illustrated. It occurs in the eastern and midwestern United States and parts of Mexico and has been reported as a pest of tulip poplar and lilac. It previously has been misidentified as H. diffinis (Newstead), which is a tropical species from the Caribbean Islands, Central America, South America, and Mexico. Lectotypes are designated for Aspidiotus diffinis Newstead, A. jatrophae Townsend and Cockerell, and A. jatrophae var. parrotti Newell. Aspidiotus fabernii Houser is transferred to Quadraspidiotus (new combination).