Flies of the curvicauda group of the genus Anastrepha with different color patterns that were previously recognized as four species are here reported to be color morphs of a single species, Anastrepha nigrotaenia (Enderlein), new combination, on the basis of morphological and molecular study. The names Toxotrypana australis Blanchard, Toxotrypana nigra Blanchard, Toxotrypana picciola Blanchard, and Toxotrypana proseni Blanchard, as well as Toxotrypana pseudopicciola Blanchard, previously considered a junior synonym of T. nigra, are here considered new synonyms of A. nigrotaenia. Specimens reared from the same samples of fruit of Araujia sericifera Brot. (Apocynaceae) in Uruguay that comprised three species based on the previous morphological concepts were nearly all identical in COI and 16S sequences and all clustered in a single clade with other specimens of these taxa in phylogenetic and multispecies coalescence analyses based on 1347 ortholog loci obtained with Anchored Hybrid Enrichment. A redescription and diagnosis are provided for A. nigrotaenia, and its host plant and distribution data are compiled and summarized.