A new species of tarsonemid mite, Steneotarsonemus hippodromus sp. nov., is described from kikuyu grass Pennisetum clandestinum (Poaceae). The new species is the fifth species of the subgenus Steneotarsonemoides. Keys to the subgenera of Steneotarsonemus and species of Steneotarsonemoides are provided, as is a list of species in each subgenus of Steneotarsonemus.