Catocala ilia (Cramer). Close to form duplicata Worthington. From Barnes, W. and J.H. Mcdunnough. 1918. Illustrations of the North American species of the genus Catocala. Memoirs of the American Museum of Natural History;n.s., vol. 3, pt. 1. DOI:http://dx.doi.org/10.5962/bhl.title.57639 Source: http://biodiversitylibrary.org/page/38534376