Abstract: A new species, Rheochlus latisetus sp. nov., is described from male and female
adults from Argentina. Emendations and illustrations of the three previously
known species of Rheochlus Brundin, 1966 are provided. A cladistic analysis of
the genus Rheochlus within the tribe Podonomini is presented, and the
phylogenetic relationship with congeners is discussed based on adult characters.
Key words: Diptera; Chironomidae; Podonominae; Rheochlus; phylogeny; cladistic analysis; new species; Argentina; Neotropical Region