Omorgus (Omorgus) fuliginosus ( Robinson, 1941 )

da Costa-Silva, Vinícius, Strümpher, Werner P., Barclay, Maxwell V. L. & Vaz-de-Mello, Fernando Z., 2024, An illustrated catalogue of South American species of Omorgus Erichson, 1847 (Coleoptera, Trogidae, Omorginae) including a neotype designation and taxonomical changes, Contributions to Entomology 74 (1), pp. 81-101 : 81-101

Omorgus (Omorgus) fuliginosus ( Robinson, 1941)

Fig. 11

Trox (Omorgus) fuliginosus Robison, 1941: 134 (original description); Blackwelder and Blackwelder 1948: 31 (checklist).

Trox fuliginosus : Vaurie 1955: 66 (redescription); Vaurie 1958: 45 (distribution); Blackwelder 1973: 35 (checklist); Ratcliffe 1978: 301 (distribution).

Omorgus fuliginosus : Baker 1968: 43 (larvae description); Deloya 1992: 3 (natural history); Deloya 1996: 43 (natural history); Morón et al. 1998: 91 (distribution); Deloya 2000: 66, 73 (checklist); Smith 2003: 6 (checklist); Deloya 2003: 130 (diagnosis and distribution); Deloya 2005: 122, 124, 128 (key); Mora-Aguilar and Montes de Oca 2009: 575 (distribution).

Omorgus (Omorgus) fuliginosus : Zidek 2013: 10 (checklist); Zidek 2017: 101 (checklist); Pablo-Cea et al. 2023: 16 (catalogue of El Salvador).

Omorgus (Omorgus) capillaceus Scholtz, 1990: 1413 (new synonym): Deloya 2005: 122 (checklist); Zidek 2013: 8 (checklist); Zidek 2017: 99 (checklist).

Type specimen examined.

Holotype, by original designation (♂ USNM – Fig. 11 ). First label [white aged, typeset]: “ New Braunfels / IV. 10 ’ 02 Tex ”. Second label [white aged, typeset]: “ H. Mittendorf / Collector ”. Third label [red, printed]: “ Type No / 55468 / USNM ”. Fourth label [red, Mark Robinson’s handwriting]: “ HOLOTYPE / Trox / fuliginosus / Mark Robinson ”. Sixth label [white, printed]: “ USNMENT / [QR Code] / 01474112 ” (Fig. 11 C ). Type locality: “ New Braunfels ” [Texas, United States].

Type specimen

of Omorgus (Omorgus) capillaceus Scholtz, 1990 (new synonym) examined. Holotype, by original designation (♀ CMNCH – Fig. 12 ). First label [white aged, unknown’s handwriting]: “ Botoga / Colombia / S. Amer. ”. Second label [white, typeset]: “ Carn. Mus. / Acc. 2275 ”. Third label [white, printed]: “ [QR code] / CMNCH - IZ / 724,596 ”. Fourth label [white with red border, Clark Scholtz`s handwriting]: “ Omorgus / capillaceus / C. H. Scholtz 1988 / HOLOTYPE ” (Fig. 12 C ). Type locality: “ Bogota, Colombia ”.

Remarks.

Omorgus (Omorgus) capillaceus was one of the species described by Scholtz in 1990 during his monographic revision of the Trogidae of South America. This species was identified in the collection of the Carnegie Museum of Natural History ( CMNCH) and described based on a single female specimen, distinguished by its morphological differences from other South American species. Scholtz noted that O. capillaceus was similar to O. monachus ( Herbst, 1790) and O. fuliginosus ( Robinson, 1941) , both of which are North American species. However, he highlighted a diagnostic feature that distinguishes O. capillaceus from other similar-looking species: the absence of a velutinous covering on the elytral disc, which is present in its relatives.

Upon reviewing the holotype of O. capillaceus , it became evident that the specimen is merely a worn variation of O. fuliginosus . While we concur with Scholtz’s observation of the glabrous elytral disc, this feature alone is insufficient for distinguishing Trogidae species without considering male genitalia. Trogidae specimens often exhibit significant intraspecific variation, and it is not uncommon to encounter specimens that are partially or entirely glabrous (or worn) in collections (V. Costa-Silva, personal observation).

Another factor that may have led Scholtz to describe a new species is the specimen’s locality: Bogota, Colombia. The holotype of O. capillaceus was associated with the label number “ 2275 ” (Fig. 12 C ), which corresponds to specimen from the Henry Klages Collection, acquired by the CMNCH on May 28, 1903 (Robert Androw, personal communication to VCS). However, as documented by Nearns and Androw (2013) and Costa-Silva et al. (2024), the Henry Klages collection has been noted for containing numerous mislabelled Nearctic and Neotropical specimens, including some cases of misidentification within the Trogidae (see Costa-Silva et al. 2024 for examples). Omorgus fuliginosus is known from the United States, Mexico, Guatemala, El Salvador, and Costa Rica ( Vaurie 1955; Ratcliffe 1978; Deloya 2000), making its record in Colombia questionable, but not impossible.

Therefore, we conclude that O. capillaceus should be considered a junior subjective synonym of O. fuliginosus , having been described based on a worn and mislabelled specimen from Bogotá, Colombia.

Geographic distribution.

Costa Rica, El Salvador, Guatemala, Mexico, and United States ( Vaurie 1955; Ratcliffe 1978; Deloya 2000).

Non-type examined material

(9 specimens). MEXICO – Veracruz • 5; Carr. Actopan, Passando la Desv. Idolos ; 30 Aug. 1994; L. Arellano & R. Sanchez leg.; CEMT • 1; Carr. Alto Lucero, Km 2 Desviación la Concepción ; 18 Oct. 1994; L. Arellano & R. Sanchez leg.; CEMT • 1; Carretera Xalapa-Alto Lucera, 1 km de Espinal ; 31 Aug. 1994; L. Arellano & R. Sanchez leg.; CEMT • 1; Catemaco, Parq. de la Flora y Fauna Silvestre tropical ; 29 Apr. 1990; F. Capistran leg.; CEMT • 1; Plan de Hidalgo, Mpio de Papantla ; 19 Mar. 1997; R. Sanchéz & M. E. Favila leg.; CEMT .

Figures

Figure 11. Holotype of Trox fuliginosus Robinson, 1941 (now Omorgus fuliginosus). A. Habitus in dorsal view; B. Habitus in lateral view; C. Labels. Photos by Robert Finn (USNM). Length of specimen: 14–15 mm.

Figure 12. Holotype of Omorgus capillaceus Scholtz, 1990. A. Habitus in dorsal view; B. Habitus in lateral view; C. Labels. Photos by Vanessa Verdecia (CMNCH).