Lieinix nemesis, the frosted mimic-white, nemesis mimic white or falcate dismorphia, is a butterfly in the Pieridae family. It is found from Mexico to Peru. The habitat consists of mid-elevation cloudforests. The wingspan is 55–65 mm (2.2–2.6 in). Adults are sexually dimorphic. The upper surface of the male forewing is black and spotted with creamy white. The female forewing is white with a black apical area and a black streak across the discal cell.