A new species, D. rengei sp. nov. of the genus Dirphia Hübner, 1819 (”1816”) (Lepidoptera: Saturniidae, Hemileucinae) is described from Zamora Chinchipe and Napo provinces of Ecuador. The male holotype is stored in the scientific collections of the Estonian Museum of Natural History, Tallinn. The new species is compared with its (probably) nearest relatives, D. radiata Dognin, 1916 and D. irradians Lemaire, 1972.