The White Underwing or The Relict (Catocala relicta) is a moth of the Erebidae family. It is found in southern Canada, from Newfoundland to Vancouver Island, south to Missouri, and Arizona. The wingspan is 67–75 mm. Adults are on wing from July to September in one generation depending on the location. The larvae feed on Betula papyrifera, Carya ovata, Populus alba, Populus balsamifera, Populus deltoides, Populus nigra, Populus tremuloides, Quercus species, and Salix species (including Salix eriocephala).