Rhoizema Barnard, 1934
Recognition of R. mahalevonum, new species expands our understanding of the morphological variation within the genus. This new species from Madagascar differs in wing shape, wing venation, shape of the maxillary palp, and male genitalic form when compared to the South African species. Thus, Barnard’s (1934) original diagnosis of males of the genus is modified as follows:
The males are recognized by having spur formula 224; ocelli absent; maxillary palps 1–2 segmented; antennae slightly longer than the forewing; forks 1 and 2 present in the forewing, fork 5 present in some species; forks 1, 2, and 5 present in the hind wing; forewing discoidal cell short, thyridial cell present or absent; in genitalia, sternum IX strongly produced posteriorly; gonocoxite clubshaped and medially bifurcate; and phallus long, slender and simple, without sclerotized processes.