Papilio marcus Fabricius, 1787

Nakahara, Shinichi, Zilli, Alberto, Calhoun, John V., Espeland, Marianne, Padrón, Pablo Sebastián & Grishin, Nick V., 2022, Resolving two centuries of mistaken identity: Reinterpretation of Papilio marcus Fabricius, 1787 (Lepidoptera: Nymphalidae, Hesperiidae), Zootaxa 5195 (3), pp. 241-255 : 243-248

Papilio marcus Fabricius, 1787

The specific epithet marcus was introduced by Johann Christian Fabricius in his Mantissa insectorvm sistens species nvper detectas adiectis synonymis, observationibvs, descriptionibvs, emendationibvs ( Fabricius 1787: 87). Like other butterfly species described in Fabricius (1787), the name appeared in combination with the generic name Papilio Linnaeus, 1758 , and this taxon is currently widely regarded as a valid species in the Neotropical skipper genus Troyus Warren & Turland, 2012 (Zhang et al. 2019: 8, Fig. 13; Fig. 1A ), although it must be noted that a few early studies did consider this taxon as conspecific with P. phyllus Cramer, 1777 (see below). Fabricius described P. marcus based on an unspecified number of specimens in the collection of “v[on]. Rohr” (i.e., Julius Philipp Benjamin von Rohr [1737-1793]), with an unknown sex from Cayenne [ French Guiana]. For over 100 years, this species-group name was associated with the skipper genus Vettius Godman, 1901 (Godman 1901: 589) , and the combination Vettius marcus was used in many important publications regarding skipper classification (e.g., Evans 1955: 182; Mielke 2004: 84; 2005: 1350). In particular, a number of publications associated this name with illustrations of the adults starting with Geyer (1832: figs 725, 726; Fig. 2 ), who placed marcus under the generic name Cobalus Hu ̈bner, [1819] ( Geyer 1832: 30; Fig. 2 ). Subsequently, the following publications illustrated the wing pattern: Draudt (1923: fig. 188g, ventral surface); Hayward (1934: fig. 21, ventral surface; 1950: pl. 24, figs 14, 15, both surfaces); Lewis (1973: figs 24, 25; 1975: figs 24, 25); Maza (1987: pl. 67, fig. 5, dorsal surface); Canals (2003: figs, both surfaces); Brown & Freitas (2000: fig., ventral surface); Glassberg (2007: 245 fig., live picture, ventral surface); Cock (2009: figs 7-9, both surfaces, live picture); Garwood et al. (2009: 328, fig., live picture, ventral surface); Garwood & Lehman (2013: 224, fig. [identical individual illustrated in preceding article]) and/or its male genitalia: Godman (1900: pl. 102, fig. 10); Hayward (1934: fig. 19; 1950: pl. 12, fig. 14); Evans (1955: pl. 66). The illustrations of genitalia in these studies reflect individuals with characters currently corresponding to the concept of “ marcus ” in the literature ( Fig. 1B ). In addition, both the wing illustrations and genitalia are consistent with each other, thus revealing a long-standing consensus about the identity of the skipper taxon represented by the name “ marcus ”.

Papilio marcus Fabricius, 1787 is in reality a junior primary homonym of Papilio marcus Schaller, 1785 , a name currently validly employed for a species of the popular butterfly genus Morpho Fabricius, 1807 ( Nymphalidae : Satyrinae ) ( Lamas 2004). Because these names apply to taxa not considered congeneric after 1899, the case needs to be referred to the International Commission on Zoological Nomenclature for a ruling under the plenary power regarding this homonymy ( ICZN 1999:Article 23.9.5). Notwithstanding this situation, an examination of the syntype of Papilio marcus Fabricius, 1787 currently housed at ZMUC (see also discussion below; Fig. 1C ) raised some questions as to its identity. Contrary to the current concept of “ marcus ”, as exemplified in the above references, the ventral surface of this male syntype in ZMUC is lacking yellow scaling at the distal side of hindwing M 3 -Cu 1 and Cu 1 -Cu 2, as well as not having whitish markings in the basal side of hindwing cells Cu 2 -2A and 2A-3A. The white marking in the ventral hindwing discal cell does not reach the distal (outer) margin in the figured specimens, whereas this corresponding marking in the syntype of P. marcus reaches the distal margin of the hindwing and, moreover, appears yellowish. Another distinctive difference is the presence of fulvous scaling along the costal and inner margins of the ventral hindwing in the syntype in Copenhagen, whereas this reddish marking is not visible on the ventral hindwing in individuals we perceive as Troyus “ marcus ”.

In fact, as indicated by one of the labels associated with this syntype in Copenhagen, these wing pattern characters suggest its identity to match that of the species currently known as Vettius phyllus ( Cramer, 1777) . Papilio phyllus was described by Pieter Cramer based on an unspecified number of specimens of an unknown sex from Suriname, owned by Enricus Fredericus Alberti ( Cramer 1777: 122). Although the number of specimen(s) is not explicitly mentioned, Cramer’s original description refers to the specimen as a singular (i.e., “ this little Plebejd.. ”), thus he likely relied on a single specimen. The illustrations of this taxon on pl. CLXXVI [176], accompanying the original description, depict the dorsal surface on Fig. B and the ventral surface on Fig. C. Based on the examination of the original illustrations by Cramer housed at NHMUK (these drawings were used to produce the hand-colored illustrations for the published book; see Chainey 2005), the apparent lack of three whitish, or silver, markings on the ventral hindwing cells M 2 -M 3, M 3 -Cu 1, and Cu 1 -Cu 2 is not in accordance with V. phyllus ; however, this illustration of the ventral surface is largely in agreement with the syntype housed at ZMUC and distinguishable from the aforementioned illustrations of “ marcus ” by the suite of characters mentioned above. To our knowledge, the syntypes of P. phyllus have not been located at RMNH (e.g., Gernaat et al. 2012; B. Hermier, pers. comm.), where some of Cramer and Stoll’s types can be found. The Rothschild collection housed at NHMUK also includes types by Cramer, mostly from the van Lennep collection. These were subsequently purchased by Cajetan Felder, although we were unable to find them in London, and thus we are unable to extend the discussion regarding application of this species-group name beyond the original description by Cramer. Based solely on a phenetic comparison, we are able to exclude a number of available names potentially applicable to the syntype of phyllus , and settle the nomenclature accordingly.

Among the taxa discussed here, the fulvous costal and inner margins of the hindwing, discernible in the marcus syntype in Copenhagen, is a feature observed in what are currently perceived as Vettius phyllus and two closely related species, namely V. chagres Nicolay, 1973 and V. mitsuko Nakahara, Nakamura & MacDonald, 2020 , and these three taxa form a clade ( Nakahara et al. 2020). However, V. chagres and V. mitsuko are both known only from Central America and are externally distinguishable from V. phyllus (see Nakahara et al. 2020) and thus are unlikely to represent the syntype of P. marcus , which is supposedly from Suriname. As evidenced by Zhang et al. (2019), seven species currently placed in Troyus - T. turneri Warren & Turland, 2012 , T. fantasos (Cramer, 1780) , T. onaca ( Evans, 1955) , T. aurelius ( Plötz, 1882) , T. “ marcus ” ( Fabricius, 1787), T. diversa (Herrich-Schäffer, 1869) , and T. drova ( Evans, 1955) - are recovered as a clade, sister to Monca Evans, 1955 and phylogenetically distantly related to Vettius . Despite some of these taxa overall resembling V. phyllus , perhaps explaining why they were previously considered congeneric under the genus Vettius (e.g., Mielke 2004, 2005), none of these species, except for Troyus “ marcus ” (see below for further discussion), possess a fulvous costal and/or inner margin of the hindwing. It therefore seems reasonable to identify the syntype of P. marcus Fabricius, 1787 as P. phyllus based on available species-group names.

The identity of the aforementioned syntype in Copenhagen as P. phyllus is also supported by the original description by Fabricius: Turton’s (1806: 169) translation - [ Papilio Hesperiae Urbicolae ] Marcus . Wing without tails brown with hyaline spots; lower-ones beneath with 2 yellowish fillets, the thinner margin fulvous. Inhabits Cayenne; small. Antennae hooked, Lower-wings with a white thinner margin and large spot in the middle above ”. Papilio phyllus , as perceived by many authors throughout history (e.g., Cramer 1777: pl. [176], figs B, C; Hayward 1934: pl. 11, figs 19, 20; Garwood et al. 2009: 328, fig.), is a widespread species in the Neotropical region and this taxon is the type species of Vettius by original designation of Godman (1901).

Latreille [1824: 753] realized that Papilio phyllus and P. marcus Fabricius, 1787 were conspecific based on the fact that the specimen he had in his hands to prepare the description of P. marcus Fabricius, 1787 possessed the bluish dorsal spots and fulvous inner hindwing margin found in P. phyllus . These two features mentioned by Latreille are present in P. phyllus and not T. “ marcus ”, as partly discussed above. The latter feature, mentioned in the description of P. marcus by Fabricius, likely influenced Latreille’s decision to regard these taxa as conspecific, although he considered P. marcus Fabricius, 1787 to be given priority for an unknown reason. Subsequently, several authors considered Papilio phyllus and P. marcus Fabricius, 1787 to be conspecific, starting with Westwood (1852: 527; P. marcus Fabricius, 1787 again as the name taking precedence), followed by Butler ([1870: 273]; P. phyllus as a senior name), Kirby (1871: 590; P. phyllus as a senior name). Plötz (1882: 454) recognized the synonymy of Latreille’s ([1824]) “ marcus ” and P. phyllus , although he regarded P. marcus Fabricius, 1787 (= phyllus sensu Kirby ) as a discrete taxon. Godman (1900: 585) also noticed these synonymous treatments of these two taxa, yet he stated that this was an erroneous taxonomic proposal. The synonymy by these authors is also reflected in Mielke (2005), but it is unfortunate that this fact did not influence a number of other authors who considered P. “ marcus ” to be a discrete taxon.

Zimsen (1964: 546) listed a single specimen for the type material of P. marcus Fabricius, 1787 as “in Kiel” (i.e., ZMUK). Fabricius’ personal collection belonging to the ZMUK was on a long-term loan to the ZMUC from 1958 to 2013, where the Sehested-Tønder Lund collection has been housed since the early 1800s, and they were kept separate ( Tuxen 1967; O. Karsholt, pers. comm.). Subsequently, it was negotiated that all specimens of Coleoptera should be transferred to ZMUK, whereas the rest of the collection should be kept in Copenhagen. As a result, all type material of Lepidoptera from Fabricius’ personal collection and the Sehested-Tønder Lund collection are now property of the ZMUC and housed accordingly.

Julius von Rohr, a German botanist in the Dutch colonial service and residing in Saint Croix, studied cotton culture and embarked on a journey to the West Indies and the northern coast of South America, including Cayenne (i.e., the type locality of P. marcus Fabricius, 1787 ) ( Millspaugh 1902). Hopkins (1999) also noted that von Rohr lived in the American tropics for 30 years, supporting the fact that he was able to directly obtain or collect specimens that were later used by Fabricius to describe P. marcus . According to Papavero (1971), von Rohr was asked by the government to travel to Jamaica, Puerto Rico, Lesser Antilles, as well as along the coast of the Guianas, and later sent back a large insect collection to Copenhagen. Existing literature also supports the claim that Julius von Rohr sent herbarium samples to Niels Tønder Lund ( Hopkins 1999), and, directly or indirectly, to Martin Vahl in Copenhagen ( Fryxell 1969; Millspaugh 1902; Hopkins 2016), as well as to Joseph Banks in London ( Hopkins 2016). Indeed, Fryxell (1969) studied the cotton plant genus Gossypium L. ( Malvaceae ) based on von Rohr’s materials in Copenhagen, which were received by Martin Vahl and remained there until his study. Hence, if insect specimens were shipped with plant materials, it is reasonable to assume that they should have ended up in Copenhagen and entered the Sehested-Tønder Lund collection, unless Banks was the recipient of von Rohr’s insects. Indeed, this taxon did not appear in Aurivillius’ (1898) list of Fabrician Lepidoptera in Copenhagen. Zimsen (1964) lists 267 insect species described by Fabricius based on materials in von Rohr’s possession, although only 13 species appear to be housed in Copenhagen, with Kiel mentioned as the repository for three of them. Henriksen (1921) described the donation of two drawers to the Danish Natural History Society by Sehested and Tønder Lund, which partly included insect materials from von Rohr, and these may have been reflected as “in Copenhagen” in Zimsen (1964). We have reviewed the correspondence between von Rohr and Joseph Banks ( Dawson 1958), and consulted with a knowledgeable historian, Daniel Hopkins (University of Missouri - Kansas City, USA) (pers. comm.), who took notes from official records of various Danish government agencies related to colonial, commercial, and financial affairs. These are all the records of correspondence von Rohr had with relevant people in Europe, in its original handwritten form, in the Danish National Archives, and we used these to trace von Rohr’s movements and to investigate how the specimen might have ended up in Kiel with Fabricius. Relevant passages include the following.

August 30, 1784: von Rohr wrote to Joseph Banks from Cayenne, where he was living for a year or so.

February 11, 1785: von Rohr is reported to still be in Cayenne, asking the Danish government for funding to return home.

When von Rohr finally gets back to St. Croix, he learned that the clove seedlings he forwarded from Cayenne were destroyed by a hurricane [in August 1785] and he turns his attention to repairs of official buildings in St. Croix.

May 31, 1786: a communication from von Rohr in St. Croix.

December 22, 1786: von Rohr receives a prize for his work in St. Croix.

October 29, 1787: the colonial office in Copenhagen refers to von Rohr, in St. Croix, where he has been given another year off from his regular duties to work on a book about cotton cultivation.

In addition, there are official communications from von Rohr in St. Croix on April 28, 1787 and July 11, 1787.

Fabricius moved to Kiel from Copenhagen in 1775 and remained there until his death in 1808 ( Tuxen 1967). Although evidence exists that Fabricius visited Copenhagen periodically starting from 1796, it is unclear whether he visited Copenhagen prior to 1787 to acquire specimen(s) he used to describe P. marcus . Nevertheless, considering the proximity of Kiel and Copenhagen, the possibility of Fabricius obtaining specimens in Copenhagen, either directly or indirectly, and ending up in Kiel is likely high. On the other hand, considering the records described here, it seems unlikely that von Rohr returned to Copenhagen, or elsewhere in Europe, in the period in question, taking into account the slowness of travel at that time. As stated in Papavero (1971), he most likely sent insects to Europe, including P. marcus , perhaps from Cayenne, in 1784 or 1785. Considering von Rohr’s correspondence with Banks during his time in the Antilles and the northern coast of South America, he might have sent specimens of P. marcus to Banks, which eventually ended up with Fabricius. Other possible recipients of von Rohr’s insect specimens include Martin Vahl, Tønder Lund and Sehested, both at Copenhagen.

Hopkins (2016) stated “ Von Rohr was travelling with three local Amerindian guides and two black slaves of his own, he wrote; one of his slaves specialised in collecting insects, the other in plants ”. An examination of correspondence between Benjamin Smith Barton and von Rohr, which took place in Philadelphia, USA, in 1793, when von Rohr visited a number of scientists, suggests that these enslaved collectors who travelled with von Rohr were named Julius and Marcus. If Marcus collected a specimen, or specimens, which Fabricius later used to describe P. marcus . it is possible that the specific epithet is based on von Rohr’s enslaved insect collector. Nevertheless, this is no more than speculation.

We have consulted with Ole Karsholt (ZMUC) to confirm that there is only a single specimen of P. marcus in Fabricius’ personal collection housed in Copenhagen, and thus the number of syntypes is in agreement with Zimsen’s (1964) type catalogue. The original description by Fabricius does not contradict this unique specimen of Papilio marcus in Copenhagen, and most likely was considered by Fabricius to represent P. marcus . Thus, it is suitable to serve as the objective standard for this named entity. Since providing evidence for the existence of additional syntype (s) is not possible, we therefore accept this male specimen as an authentic syntype of P. marcus Fabricius, 1787 . Consequently, we designate this specimen as the lectotype of P. marcus Fabricius, 1787 in order to settle the nomenclature and identity, as perceived in the present study (i.e., as a junior synonym of P. phyllus ) (lectotype designation). Although three subspecific names have been associated with P. phyllus ( Mielke 2005) , the marcus lectotype from Cayenne is likely to represent the nominate race, considering that the type locality of P. phyllus lies in its neighboring Suriname.

Given that we identified the syntype of P. marcus Fabricius, 1787 as P. phyllus , we review species-group names historically associated with P. “ marcus ” in order to find a name that suits the current concept of P. “ marcus ”, as outlined above.

Figures

FIGURE 1. Pictures of relevant Troyus species:A) sequenced Troyus phyllides from Suriname (molecular voucher: 19022E04; deposited in USNM); B) genitalia of Troyus phyllides from Rondônia, Brazil (dissection vial: SN-20-107; deposited in MGCL); C) Lectotype of Papilio marcus Fabricius, 1787 housed in ZMUC (ZMUC 00029699); D) Lectotype of Vettius phyllides housed at SMT (molecular voucher: 18094F06).

FIGURE 2. The earliest recorded illustrations of “marcus” (placed in the genus Cobalus) in Geyer (1832). From the Ernst Mayr Library and Archives of the Museum of Comparative Zoology, Harvard University.