Beckocoris Knight, 1968, is revised and redescribed; three new species—B. brendae, B. inventarium, and B. lattini—are described; and Nevadocoris bullatus Knight, 1968, is transferred to Beckocoris, n. comb. All species of Beckocoris are recorded breeding on species of Tetradymia (Asteraceae) with additional records from Chrysothamnus spp. (Asteraceae) and “Dalea” (Fabaceae: Papilionoideae). Nevadocoris Knight, 1968, is revised, redescribed, and two new species—N. lattini and N. tetradymii—are described; all species are recorded breeding on Tetradymia spp., with additional records from Chrysothamnus spp., “Dalea” and Phlox (Polemoniaceae). Species within each genus have largely allopatric distributions within the Great Basin, including most of the Mojave Desert in the south, as well as parts of eastern Utah. Lattinophylus artemisii, new genus and new species, is described as breeding on Artemisia spp., primarily A. tridentata (Asteraceae), with a range largely coterminous with species of Beckocoris and Nevadocoris.