Calotheca Heyden, 1887 is a flea beetle genus that occurs predominantly in sub-Saharan Africa, comprising 29 species. The examination of new material is revealing a significantly higher species richness and high intraspecific variability. A group of five species, occurring in the southernmost portion of the distribution range for the genus, is here attributed to the C. parvula species group: C. parvula (Weise, 1908), C. pallida (Bryant, 1945), C. danielssoni sp. nov., C. oberprieleri sp. nov., and C. prinslooi sp. nov. Species in the C. parvula group have strong similarities in body shape and sculpture on the integument, spermathecal shape, and for most species the morphology of the median lobe of the aedeagus. A key to species of the Calotheca parvula group is provided along with photographs of the habitus, main diagnostic characters, median lobe of the aedeagus and spermatheca. In addition to the geographic distribution, the available information on the habitat, host plants, and phenology are provided for the five species analysed.