The South African sister genera Parapseudosthenarus Schuh and Pseudosthenarus Poppius are revised. A monophyletic group containing both genera is diagnosed. Two new species of Parapseudosthenarus are described, bringing the total to three. Seven new species of Pseudosthenarus are described, bringing the total to 11. Morphological details are documented with light and scanning electron microscopy; whole insects are documented with colour digital photographs. Approaches to species discrimination are discussed. Parapseudosthenarus is shown to be broadly distributed across South Africa and Namibia whereas Pseudosthenarus is restricted to Namaqualand and the Little Karoo. Extensive host documentation is presented, indicating that both insect genera are restricted to plant genera placed in the tribe Crotalarieae (Fabaceae: Faboideae), and that most species are restricted to a single host genus; most Pseudosthenarus species breed only on the monophyletic Cape Group within Crotalarieae. Host plants are documented with colour digital images from the field and from herbarium specimens.