Ootheca mutabilis (Schönherr) and O. bennigseni Weise are recognized as two prominent pest species on beans (Phaseolus vulgaris (L.), Fabaceae), in Central and East Africa. These beetles destroy root tissue and seedlings, skeletonize the leaves of plants and feed on inflorescences, causing serious crop losses. Both species also feed on cowpeas (Vigna unguiculata (L.) Walp. (Fabaceae). Ootheca mutabilis is known to be a vector of several plant viruses. The current taxonomic status of the African genus Ootheca is discussed, and the following species are transferred from the genus Ergana Chapuis to Ootheca Dejean as new combinations: O. bifrons (Laboissière), O. bourquii (Laboissière), O. caerulea (Jacoby), O. fulvipes (Jacoby), O. chapuisi (Jacoby), O. minuta (Laboissière), O. nigrilabris (Laboissière), O. podagrica (Laboissière), O. proteus (Chapuis), O. semicaerulea (Jacoby), O. variabilis (Laboissière), and O. vittata (Laboissière). Ootheca vexa nom. n. is proposed as the replacement name for Ootheca apicicornis (Laboissière) comb. n. (from Ergana), a junior homonym of O. apicicornis Laboissière. Ootheca mutabilis and O. bennigseni have been studied to provide information and illustrations to facilitate their identification. Ootheca meridiana sp. n. is described as a new pest species of beans and cowpeas from southern Africa.