Teratopomyia Oldroyd, 1980 is monotypic. Tetrapomyia cyanea (Fabricius, 1781), the oldest known southern African asilid species, remains the only species after a study of 184 specimens. No evidence could be found to suggest that undescribed species or even geographical variants exist. It is not a commonly encountered species and is usually found in low numbers. Although superficially similar to representatives of other genera, relationships within the subfamily will only be known once phylogenetic studies have been conducted. Tetrapomyia cyanea is widely distributed in South Africa, but most commonly encountered in the Western Cape and Eastern Cape provinces. While there is some evidence of an association with flowering plants, this may be indirect and relate to prey availability.