A series of 15 species described from specimens collected from the leaves of mango trees at a single site in Mexico are newly placed as synonyms of the California citrus thrips, Scirtothrips citri (Moulton) (Thysanoptera: Thripidae). These species were originally discriminated based on differences in the precise placement of setae in the median area of the pronotum, and this chaetotaxy is here recognized as variable within populations of this thrips from various sites in California and Mexico. Preliminary results from molecular analysis of 2 genes, CO1 and 28S-D2, indicate that there is variation at the molecular level between populations of S. citri. However, this variation is not sufficient to support new species designations, and no consistent morphological divergence between these populations was detected.