Lycomorpha desertus is a moth of the Arctiidae family. It was described by H. Edwards in 1881. It is found in Arizona. The wingspan is about 31 mm. Adults resemble Lycomorpha pholus, but the black area of the forewings is less extensive. The thorax are orange. The abdomen of the females is orange above and below and the abdomen, antennae and tarsi of the males are black.