SYNTYPES [4♂ 3♀] Mexico: Guadalajara, vii «viii.1896» («W.» Schaus) [2♂ 2♀ NHMUK; 2♂ 1♀ ????].
Rothschild & Jordan 1903, Novit. zool. 9 (suppl.): 436, gave the type data as: “In the Tring Museum 4♂♂ 4♀♀ from : Guadalajara, Mexico, vii. (Schaus), type : Tucuman”. Although the punctuation is ambiguous, it is interpreted here to indicate that Rothschild & Jordan considered only the specimens from Guadalajara were “type(s)”, and they are here interpreted as syntypes. The specimen (s) from Tucuman are considered not to be type material. Only one specimen, a female, from “Tucuman” with appropriate label data has been located in the NHMUK, leaving a potential seven syntypes from Guadalajara. Of these, one two males and two females have been found; the location of the remaining two males and one female is unknown. It should also be noted that Rothschild & Jordan gave an incorrect capture date of “vii” [July]; all the syntype labels, however, state “viii” or “August”.
Proposed as a subspecies of Sesia tantalus. Raised to species status by Jordan, 1924, Novit. zool. 31: 298. Erroneously resynonymized with Sesia tantalus as a form by Barnes & Benjamin, 1927, Bull. Southern Calif. Acad. Sci. 26: 38. Reinstated as a species by Hodges, 1971, in Dominick et al., Moths Amer. N. of Mexico 21: 110 (key), 111.