TL;DR: Four North American species of hackberry specialists and a new species, which is the western sister taxon of the latter, are described.
Abstract: . The genus Rifargia includes four North American species: R. benitensis (Blanchard), R. ditta (Barnes and McDunnough), R. subrotata (Harvey), and a new species, which is the western sister taxon of the latter. All are hackberry (Celtis) specialists. We provide images for each species, a larval key, and brief descriptions of the five instars for both of the eastern species (R. benitensis and R. subrotata).