Pseudocanthon perplexus ( LeConte, 1847 )

Nazaré-Silva, Everton E. & Silva, Fernando A. B., 2021, A taxonomic revision of the South American species of Pseudocanthon Bates, 1887 (Coleoptera: Scarabaeidae: Scarabaeinae: Deltochilini), Zootaxa 5027 (1), pp. 61-86 : 66

Pseudocanthon perplexus ( LeConte, 1847)

( Figs. 2E , 3A , 4A , 5A , 6A , 7A )

Canthon perplexus LeConte, 1847: 85 (original description); LeConte 1859: 11 (description); LeConte 1863: 36 (checklist); Harold 1868: 67 (description); Harold 1869: 992 (catalogue and distribution); Horn 1870: 46 (description); Blanchard 1885: 164, 167 (description, distribution, and identification key); Kolbe 1905: 579 (description); Blatchley 1910: 915 (description and distribution); Gillet 1911: 31 (catalogue and distribution); Blatchley 1918: 54 (checklist and distribution); Leng 1920: 248 (catalogue and distribution); Schmidt 1922: 64, 78 (description and distribution); Balthasar 1939: 190 (description and distribution); Islas 1942: 334 (identification key); Robinson 1948: 86, 97 (description, distribution, and identification key); Matthews 1966: 83 (cited as type species of Pseudocanthon ); Howden & Young 1981: 35 (cited as type species of Pseudocanthon ).

Canthon perplexum: Blackwelder 1944: 200 (checklist and distribution); Roze 1955: 42 (checklist).

Canthon (Pseudocanthon) perplexus: Krajcik 2006: 29 (checklist); Krajcik 2012: 64 (checklist).

Pseudocanthon perplexus: Bates 1887: 35 (catalogue and distribution); Pereira & Martínez 1956: 109 (taxonomic remarks); Halffter 1961: 232–233 (taxonomic remarks); Vulcano & Pereira 1964: 591–592 (catalogue and distribution); Vulcano & Pereira 1967: 551 (identification key); Halffter & Martínez 1977: 60 (checklist); Howden & Young 1981: 35–36 (description, distribution, and taxonomic remarks); Barbero 2001: 3 (checklist); Medina et al. 2001: 137 (checklist); Navarrete-Heredia et al. 2001: 54 (checklist); Ratcliffe 2002: 13 (checklist); Smith 2009: 40 (checklist); Hamel-Leige et al. 2006: 14 (checklist); Ivie & Philips 2008: 11–12 (checklist, distribution, and taxonomic remarks); Medina & Pulido 2009: 59 (checklist); Carvajal et al. 2011: 119, 314 (checklist and distribution); Solís & Kohlmann 2012: 4 (checklist); Taboada- Verona et al. 2019: 589 (checklist); Schoolmeesters 2020 (catalogue); Vaz-de-Mello 2020 (checklist).

Pseudocanthon perplexum: Martínez 1947: 267 (catalogue); Vaz-de-Mello 2000: 194 (checklist).

Diagnosis. Pseudocanthon perplexus is similar to P. xanthurus in having inconspicuous microsculpture at central portion of pronotum ( Fig. 2B ). However, P. perplexus can be distinguished from P. xanthurus by the following characters: dorsal surface of body almost completely black or metallic blue, orange portion restricted to clypeal surface ( Fig. 3A ); internal edge of protibia strongly arched ( Fig. 2E ); apex of parameres curved inward, with small cylindrical projection at apex of ventral edge ( Fig. 5A ); frontolateral peripheral (FLP) endophallite elongate, bifurcate at inferior portion ( Fig. 6A ); and accessory endophallite (AE) present ( Fig. 6A ). On the other hand, in P. xanthurus surface of clypeus, lateral edges of pronotum, humeral angle, lateral and apex of elytra with orange spots ( Fig. 3B–C ); internal edge of protibia substraight ( Fig. 2F ); apex of parameres rounded, curved outward ( Fig. 5B–C ); FLP elongate, elliptical shaped ( Fig. 6B ); and AE absent ( Fig. 6B ).

Type material. Canthon perplexus LeConte holotype ♀ ( MCZC; 1 specimen): “TYPE / 3703 ” // “ C. perplexus / Lec. ” [LeConte’s handwriting], yellow disc.

Non-type material examined. 1♀ and 3♂. VENEZUELA: BARINAS: Santa Bárbara , [07°48’50.42’’N; 71°10’30.57’’W], 185 m, IV.1981, no collector — 1♀ 3♂ ( CMNC) .

Distribution. From South America, we were able to examine only specimens from Venezuela. According to literature data, this species was also cited from Colombia and Brazil (Amazon region) by Vulcano & Pereira (1964, 1967), and Colombia by Howden & Young (1981). Specimens from the Howden collection were deposited at the CMNC. Since no P. perplexus specimens from Colombia were found in the CMNC, the Howden & Young (1981) record was likely based on a misidentification. We are not sure about these records since we have not examined that material. Thus, we have included a “?” next to these records at distribution map ( Fig. 7A ). The currently known distributional range for P. perplexus is from south of the United States of America to Venezuela, including Bahamas and Trinidad, in the Antilles ( Vulcano & Pereira (1964); Ivie & Philips, (2008)). Areas of endemism [South America]: Brazilian sub-region: Pacific dominion: Guajira and Magdalena provinces. Boreal Brazilian dominion: Imerí province (see Morrone 2014: fig. 12).

Note about the holotype of Canthon perplexus LeConte, 1847 . Since LeConte (1847) explicitly mentioned in his description that the species was based on a single specimen, it is the holotype by monotypy. The MCZC specimen listed above is undoubtedly the holotype because it is housed in LeConte’s personal collection at MCZC, has an identification label with the name “ C. perplexus ” in LeConte’s handwriting (see Horn et al. 1990), and agrees with the the original description.

Figures

FIGURE 2. Details of the external morphology in species of Pseudocanthon Bates, 1887. A, P. vazdemelloi new species pronotal disc; B, P. xanthurus (Blanchard, 1847) pronotal disc; C, P. vazdemelloi new species detail of left lateral of elytron; D, P. pantanensis new species detail of left lateral of elytron (arrow indicates eighth elytral stria present); E, P. perplexus (LeConte, 1847) protibia in dorsal view (arrow indicates median emargination); F, P. xanthurus (Blanchard, 1847) protibia in dorsal view; G. P. pantanensis new species pygidium; H, P. chaquensis new species pygidium. Scale bar: 0.5 mm (2A–D); 0.2 mm (2E–H).

FIGURE 3. South American species of Pseudocanthon Bates, 1887, dorsal view. A, Pseudocanthon perplexus (LeConte, 1847); B–C, P. xanthurus (Blanchard, 1847); D, P. vazdemelloi new species; E, P. pantanensis new species; F, P. chaquensis new species. Scale bar: 1 mm (3A–E); 2 mm (3F).

FIGURE 4. South American species of Pseudocanthon Bates, 1887, ventral view. A, Pseudocanthon perplexus (LeConte, 1847); B, P. xanthurus (Blanchard, 1847); C, P. vazdemelloi new species; D, P. pantanensis new species (arrows indicate angulation at posterior edge of metafemur); E, P. chaquensis new species (arrows indicate angulation at posterior edge of metafemur). Scale bar: 1 mm (3A–E); 2 mm (3F).

FIGURE 5. Aedeagus in South American species of Pseudocanthon Bates, 1887, lateral and ventral views, respectively. A, Pseudocanthon perplexus (LeConte, 1847); B–C, P. xanthurus (Blanchard, 1847) (arrows indicate variation at apex of parameres); D. P. vazdemelloi new species; E, P. pantanensis new species; F, P. chaquensis new species. Scale bar: 0.5 mm.

FIGURE 6. Endophallites in South American species of Pseudocanthon Bates, 1887. A, Pseudocanthon perplexus (LeConte, 1847); B–C, P. xanthurus (Blanchard, 1847); D, P. vazdemelloi new species; E, P. pantanensis new species; F, P. chaquensis new species. Accessory endophallite (AE). Complex of axial and subaxial (A+SA) endophallite. Frontolateral peripheral (FLP) endophallite. Superior right peripheral (SRP) endophallite. Scale bar: 0.2 mm.

FIGURE 7. Known distribution in South America of species of Pseudocanthon Bates, 1887. A, P. perplexus (LeConte, 1847) and P. xanthurus (Blanchard, 1847); B, P. vazdemelloi new species, P. pantanensis new species, and P. chaquensis new species.