Katydids of the genus Ewanella Naskrecki (Mecopodinae) and stick-like katydids of the genus Conocephalus Thunberg (Conocephalinae) are reviewed. The latter representatives are included in the subgenus Megalotheca Karny, stat. n., which was formerly considered a separate genus but is here reduced to a subgenus of Conocephalus. Three new species from South Africa are described: E. breviuscula sp. n., C. (M.) namibius sp. n., and C. (M.) zlobini sp. n. Identification keys to all species of Ewanella and Megalotheca are given.