Ferreira, W.D., Oliveira, L.A.D., Inez, T.G. & Hermes, M.G. (2017) A new species of Pirhosigma Giordani Soika, 1978 (Hymenoptera, Vespidae: Eumeninae), with additional notes and a key to the species in the genus. Zootaxa, 4300 (2), 269–278.