A key to species, descriptions of species, synonymical names, and geographical distribution are presented for the 114 species of Acanthoscelides known to occur in the study area. Of the 114 species, 57 are new and host associations are reported for 97 species. Host associations are primarily with seeds of papilionoid Leguminosae. Seeds of mimosoid and caesalpinoid legumes are also fed upon as are seeds of the plant families Malvaceae, Onagraceae, Rhamnaceae, Sterculiaceae, and Tiliaceae. One surprising finding of the study is that fully 20 species of Acanthoscelides feed in seeds of the Malvaceae. The legume genera Mimosa, Senna, Rhynchosia and Desmodium are the hosts most preferred by the species treated here, but at least 27 other legume genera are fed upon.