Lithurgus planifrons Friese, 1908 - Vergara & Ayala, 2002Vergara, C.H. & R. Ayala 2002. Diversity, Phenology and Biogeography of the bees (Hymenoptera: Apoidea) of Zapotitlán de las Salinas, Puebla, Mexico. Journal of the Kansas Entomological Society 75 (1):16-30. (distribution); Yáñez-Ordóñez & Hinojosa-Díaz, 2004Yáñez-Ordóñez, O. & I. Hinojosa-Díaz 2004. La colección himenopterológica (Insecta) del Museo de Zoología Alfonso L. Herrera de la Facultad de Ciencias, UNAM, México. Acta Zoológica Mexicana (nueva serie) 20 (1):167-197. (distribution); Nava-Bolaños & Osorio-Olvera, 2022Nava-Bolaños, A. & L. Osorio-Olvera 2022. Estado del arte del conocimiento de biodiversidad de los polinizadores de México. Revista Mexicana de Biodiversidad 93:1-77. (distribution). - As Lithurge planifrons: - Snelling, 1983Snelling, R.R. 1983. The North American species of the bee genus Lithurge (Hymenoptera: Megachilidae). Contributions in Science, Natural History Museum Los Angeles County 343:1-11. (distribution); Snelling, 1986Snelling, R.R. 1986. The taxonomic status of two North American Lithurge (Hymenoptera: Megachilidae). Bulletin of the Southern California Academy of Science 85 (1):29-34. (distribution); Ayala, 1988Ayala, R. 1988. Abejas silvestres (Hymenoptera: Apoidea) de Chamela, Jalisco, México. Folia Entomológica Mexicana 77:395-493. (distribution). - As Lithurgopsis planifrons: - Sagot et al., 2018Sagot, P, J. Mérida, R. Ayala & R. Vandame 2018. Situación actual del conocimiento de la fauna de abejas (Apoidea: Anthophila) del estado de Chiapas, México. In: (Ed.). Memorias X Congreso Mesoamericano sobre Abejas Nativas. 191-2011. (distribution).
Lithurgus socorroensis Mitchell, 1938:152, ♂♀. Holotype ♀, Braithwaite Bay, Socorro Island, Revillagigedo Group (Mexico), May 7, 1925 (Calif. Ac. Sc., no. 4602, leg. H.H. Keifer); Snelling, 1983Snelling, R.R. 1983. The North American species of the bee genus Lithurge (Hymenoptera: Megachilidae). Contributions in Science, Natural History Museum Los Angeles County 343:1-11.:10, Holotype ♀ (California Academy of Sciences, San Francisco). Synonymized with Lithurge planifrons (Friese, 1908) by Snelling, 1986Snelling, R.R. 1986. The taxonomic status of two North American Lithurge (Hymenoptera: Megachilidae). Bulletin of the Southern California Academy of Science 85 (1):29-34.:29. - As Lithurge socorroensis: - Snelling, 1983Snelling, R.R. 1983. The North American species of the bee genus Lithurge (Hymenoptera: Megachilidae). Contributions in Science, Natural History Museum Los Angeles County 343:1-11. (distribution).