Synonymized with Sphinx cestri [sic] by Burmeister, 1878, Descr. physique R├®publique Argentine5 (L├®pid.) (1): 321. Reinstated as a species by Kirby, 1892, Synonymic Cat. Lepid. Heterocera1: 689. Rothschild & Jordan, 1903, Novit. zool.9 (suppl.): 75, incorrectly treated diffissa as a junior name of Protoparce petuniae. This error was corrected by Rothschild & Jordan, 1903, Novit. zool.9 (suppl.): 935. However, K├Âhler, 1924, Z. wiss. InsektBiol.19 (Sonderheft): 6, and Bryk, 1953, Ark. Zool. (N.S.) 5: 151, among others, continued erroneously to treat petuniae as the senior name. Transferred to Manduca by d'Abrera, , Sphingidae Mundi: 26.