Eudamus oenander Hewitson, 1876

Zhang, Jing, Cong, Qian, Shen, Jinhui, Song, Leina & Grishin, Nick V., 2025, Advancing butterfly systematics through genomic analysis, The Taxonomic Report of the International Lepidoptera Survey 12 (5), pp. 1-201 : 89-90

Investigations into Eudamus oenander Hewitson, 1876

Eudamus oenander was described by Hewitson (1876) from an unstated number of specimens from Pará, Brazil, in the Staudinger collection. The description is short, and its major part, written in English that expands on the Latin preamble, is quoted here in its entirety: “Upperside rufous-brown, the base of both wings blue. Underside rufous-brown. Anterior wing with the costal margin blue from the base to the middle, the inner margin broadly white. Posterior wing lobed, darker at the middle, followed by a band of paler colour. Exp. 1 6/ 10 inch. Hab. Pará. In the collection of Dr. Staudinger. ” This description likely refers to a single specimen, because no others were mentioned, and a single measure (not a range) is given for wingspan. Nevertheless, avoiding the assumption of the holotype to follow the ICZN Code Recommendation 73F ( ICZN 1999), we consider any type specimens of E. oenander to be syntypes.

No known E. oenander syntypes have been reported (Evans 1952; Steinhauser 1987). If they are still extant, they could be in MFNB (most likely) and possibly in ZSMC, or even MTD (the least likely possibility), where the specimens from the Staudinger collection are currently housed. N.V.G. searched for the syntypes of E. oenander in Hesperiidae holdings of these three collections, including unsorted material. Known Hewitson syntypes in the Staudinger collection bear a label with a single word in Hewitson’s handwriting: the taxon name. For instance, a male syntype of Eudamus aegiochus Hewitson, 1876 (currently in the genus Celaenorrhinus Hübner, [1819] ), described in the same publication with E. oenander , is housed in the MFNB collection, and bears such a label “ AEgiochus ”. Syntypes of E. oenander were not found, and we proceeded to figure out the taxonomic identity of E. oenander from its description and other publications.

Williams and Bell (1934) synonymized E. oenander with Telegonus creteus (Cramer, 1780) (type locality in Suriname): “The description of oenander indicates a typical creteus , of which, Capt. Riley informs us, there is no specimen in the Hewitson Collection, nor is there any specimen under the name oenander .” Evans (1952) treated E. oenander as “ Astraptes chiriquensis oenander ”, also placing it with species currently in the genus Telegonus Hübner, [1819] (type species Papilio talus Cramer, 1777 ). However, according to the original description, E. oenander is a medium-sized species, about 4 cm in wingspan (1 6/ 10 inches). Even if it is spread with forewings pulled up to minimize the wingspan, specimens of Telegonus are rarely this small (e.g., some T. parmenides ). Furthermore, the description does not match Telegonus in its details, e.g., we are yet to find a Telegonus specimen with the blue along the forewing costa beneath reaching its middle, rarely its third, and the ventral hindwing is typically with two variously developed bands, not “darker in the middle” with the paler band distad of the darker area.

Therefore, judging from the specimen size, blue wing bases above, forewing beneath with blue costa to its middle and large white tornal area, and lobed hindwing beneath with central dark area with a paler band distad, E. oenander could have been a species of Ectomis Mabille, 1878 , Aroma Evans, 1955 , or possibly some other medium-sized species in this mimicry complex. Several known Ectomis species (e.g., Ectomis bahiana ( Herrich-Schäffer, 1869) and males of Ectomis pervivax (Hübner, [1819])) agree with Hewitson’s description, but they also have bluish ventral hindwing bases, and at least a trace of a

white spot in the middle of the ventral forewing costal margin. These two obvious characters were not mentioned in the original description, and therefore, it is less likely that E. oenander belongs to Ectomis . Conversely, Aroma aroma (Hewitson, 1867) (type locality in Brazil: Pará) agrees with the description nearly perfectly, and Eudamus oenander may be this species, re-described by Hewitson from the same locality nearly a decade later. Moreover, another species of Aroma was proposed by Staudinger (1875) in the genus Telegonus as T. henricus , highlighting similarities in appearance between these species as a source of confusion about their classification. Therefore, we propose to treat Eudamus oenander Hewitson, 1876 as a junior subjective synonym of Aroma aroma (Hewitson, 1867) , new synonym placement, while we continue our search for syntypes of this taxon.

We conclude that E. oenander does not belong to Telegonus , and Evans (1952) misidentified this species. We employ the name Telegonus creteus (Cramer, 1780) (type locality in Suriname) for some specimens that Evans (1952) identified as “ Astraptes chiriquensis oenander ” because out of all Telegonus species currently known from the Guianas, these specimens match best the original description and illustrations of T. creteus . Furthermore, the name of the species Evans (1952) identified as “ Astraptes creteus creteus ” is Telegonus parmenides ( Stoll, 1781) (type locality in Suriname), according to our investigation presented above. Evans (1952) treated T. parmenides as a junior subjective synonym of his “ A. creteus creteus ”.