The allocation of species to species groups within the genus Bombylisoma Rondani by previous authors is discussed and examined by means of phylogenetic analysis. Most characters previously used to define species groups are shown to exhibit a high degree of homoplasy but characters of the male genitalia provide synapomorphies uniting groups of species. As a result of the analysis a new genus Eremyia gen. n. is proposed for B. argentatum (Greathead) and allied species and species groups are defined: a B. minimum (Scopoli) group; a B. senegalense (Macquart) group; a B. tripunctatum (Macquart) group; and a B. argyropygum (Wiedemann) - B. nucale (Bezzi) group. A key is provided for the identification of the Afrotropical species. B. pectorale (Loew) and B. gibbicorne (Bezzi) are shown to be synonyms of B. senegalense (Macquart), and B. twiga sp. n. is described from Kenya.