The Elm sphinx, (Ceratomia amyntor), sometimes called the Four-horned Sphinx, is a North American species of moth in the Sphingidae family. It has a wingspan of 3¼ - 4½ inches (8.2 - 11.5 cm). As the name suggests, the larvae (caterpillars) feed on elm trees (Ulmus), but they can also be found feeding on birch (Betula), basswood (Tilia), and cherry (Prunus).