Aulacus ruficeps Westwood, 1851:224, sex not indicated.Para Brasiliae (Mus. Britann.); Smith, 2005Smith, D.R. 2005. Aulacidae (Hymenoptera) of northern South America, emphasizing Colombia. Transactions of the American Entomological Society 131 (1+2):217-253.:247, Holotype (BMNH, Hym. 3.0.137), Lectotype ♀, examined (Natural History Museum, London, UK, Hym. 3.0.137), designated by Smith, 2018Smith, D.R. 2018. Neotropical Pristaulacus Kieffer (Hymenoptera: Aulacidae), species with acute anterolateral mesonotal projections. Transactions of the American Entomological Society 144:309-345.:332. - Schletterer, 1889Schletterer, A. 1889. Die Hymenopteren-Gruppe der Evaniiden. Annalen des Naturhistorischen Museums in Wien 4:107-180; 289-338; 373-546. (distribution). - As Pristaulacus ruficeps: - Smith, 2005Smith, D.R. 2005. Aulacidae (Hymenoptera) of northern South America, emphasizing Colombia. Transactions of the American Entomological Society 131 (1+2):217-253. (distribution); Smith, 2018Smith, D.R. 2018. Neotropical Pristaulacus Kieffer (Hymenoptera: Aulacidae), species with acute anterolateral mesonotal projections. Transactions of the American Entomological Society 144:309-345. (distribution).
Aulacus bicornutus Schletterer, 1889:529, ♀. Holotype ♀, Brasilien (Teffé am Amazonenstrome) (königl. naturhistorische Nationalmuseum zu Budapes), Lectotype ♀, examined (Hungarian Natural History Museum), designated by Smith, 2005Smith, D.R. 2005. Aulacidae (Hymenoptera) of northern South America, emphasizing Colombia. Transactions of the American Entomological Society 131 (1+2):217-253.:247; Smith, 2018Smith, D.R. 2018. Neotropical Pristaulacus Kieffer (Hymenoptera: Aulacidae), species with acute anterolateral mesonotal projections. Transactions of the American Entomological Society 144:309-345.:332, Lectotype ♀ (Hungarian Natural History Museum, Budapest). Synonymized with Pristaulacus ruficeps (Westwood, 1851) by Smith, 2005Smith, D.R. 2005. Aulacidae (Hymenoptera) of northern South America, emphasizing Colombia. Transactions of the American Entomological Society 131 (1+2):217-253.:243. - Dalla Torre, 1901-1902Dalla Torre, C.G. 1901-1902. Catalogus Hymenopterorum hucusque descriptorum systematicus et synonymicus. — Volumen III: Trigonalidae, Megalyridae, Stephanidae, Ichneumonidae, Agriotypidae, Evaniidae, Pelecinidae. Pars II. Breitkopf & Härtel, Leipzig. VIII + 1141. (distribution); Smith, 2018Smith, D.R. 2018. Neotropical Pristaulacus Kieffer (Hymenoptera: Aulacidae), species with acute anterolateral mesonotal projections. Transactions of the American Entomological Society 144:309-345.:332 ( listed as synonym of Pristaulacus ruficeps (Westwood, 1851)).