A new subspecies within the Simulium damnosum complex is described from the Lualaba river, East Zaire, on the basis of polytene chromosome analysis and larval morphology, under the name Simulium (Edwardsellum) squamosum kitetense ssp. n. Chromosomally it is most similar to S. squamosum, from which it differs by three new fixed inversions. Morphological differences include a reduced number of rays on the premandibular fans, the particular aspect of the combs on those rays, and the general colour of the body which is a very light yellow. A second population from a nearby river was morphologically and chromosomally quite different, although more samples are needed to clarify its taxonomic position.