Research Article |
Corresponding author: Vinícius da Costa-Silva ( silvavinicius92@gmail.com ) Academic editor: Vinicius S. Ferreira
© 2024 Vinícius da Costa-Silva, Werner P. Strümpher, Maxwell V. L. Barclay, Fernando Z. Vaz-de-Mello.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
da Costa-Silva V, Strümpher WP, Barclay MVL, Vaz-de-Mello FZ (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): 81-101. https://doi.org/10.3897/contrib.entomol.74.e126799
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An illustrated catalogue of South American species of the genus Omorgus Erichson is presented. Based on this study we propose the following taxonomic changes: Omorgus (Omorgus) capillaceus Scholtz, 1990, syn. nov. and Omorgus (O.) lucidus Pittino, 2010, syn. nov. are proposed as junior subjective synonyms of Omorgus (O.) fuliginosus (Robinson, 1941) and Omorgus (O.) ciliatus (Blanchard, 1847), respectively. Lastly, we designated a male neotype for the ubiquitous New World species Trox suberosus Fabricius, 1775 to replace the missing type.
Keratin feeding, Omorgini, Scarabaeoidea, South America, taxonomy, type specimens
Omorgus Erichson, 1847 (Scarabaeoidea, Trogidae) is a diverse and widespread genus of Trogidae MacLeay, 1819 with c. 150 valid names (
From South America, 17 species of Omorgus are recognized after the studies carried out by
Thus, our main goal is to present an illustrated catalogue of those name-bearing type specimens of South American species of Omorgus whose images have never been published before. Our results, as well as the publication by
A total of 899 specimens of Omorgus (including types and non-type material) from the institutions listed below were examined. The curators are presented in brackets.
CEMT Coleção Entomológica de Mato Grosso Eurides Furtado, Cuiabá, Mato Grosso, Brazil (Fernando Z. Vaz-de-Mello)
CVMD Collection of Víctor Manuel Diéguez [Private Collection], Peñalolén, Santiago, Chile (Víctor Manuel Diéguez).
IADIZA Instituto Argentino de Investigaciones de Zonas Áridas, Mendoza, Mendoza, Argentina (Gustavo Flores and Sergio Roig).
RPMI Collection of Riccardo Pittino [Private Collection], Milan, Italy (Riccardo Pittino).
ZMUK Zoologisches Museum, Universität Kiel, Kiel, Germany (Michael Kuhlmann)
Label data for primary type specimens are transcribed ipsis litteris in quotation marks (“…”). Forward slashes “/” were used to indicate a new line of text on the same label. Comments and additional information are provided in square brackets “[…]”. All handwritten information is underlined. The non-type material follows the format present by
All images taken by the authors were made using a Leica model m205C stereomicroscope with MC190 HD image capture system. Photographs that were not taken by the authors are indicated in the captions of the respective images with the respective copyright of the author and the museum.
Order Coleoptera
Family Trogidae MacLeay, 1819
Subfamily Omorginae Nikolajev, 2005
Tribe Omorgini Nikolajev, 2005
For morphological description and diagnosis, see
Trox suberosus Fabricius, 1775 (by subsequent designation, Lacordaire, 1856).
The identification keys of
Trox batesi
Harold, 1872: 126 (original description);
Trox (Omorgus) batesi:
Omorgus (Haroldomorgus) batesi:
Omorgus batesi:
Holotype
(♂
Argentina, Bolivia, Brazil and Paraguay (
(four specimens additionally to
The monotypic subgenus Haroldomorgus Scholtz, 1986a was established to accommodate Trox batesi Harold, 1872, following a morphological phylogenetic analysis aimed at elucidating the suprageneric relationships within Trogidae (refer to Scholtz, 1986a for details). One of the most distinctive features of Omorgus (Haroldomorgus) species is a complete absence of tubercles or ridges on the pronotum and elytra. Additionally, this species exhibits an oval-shaped scutellum that is not constricted at the base, which distinguishes it from the typical modern concept of Omorgus species. Following a morphological phylogenetic analysis conducted by some of the authors (VCS, WPS, and FZVM –
Trox badeni
Harold, 1872: 83 (original description);
Omorgus (Omorgus) badeni:
Omorgus badeni:
Lectotype
(
Brazil. For details of distribution, see
Trox borrei
Harold, 1872: 84 (original description);
Trox (Omorgus) borrei:
Omorgus (Omorgus) borrei:
Omorgus borrei:
Lectotype
(
Argentina, Bolivia, Brazil, Paraguay and Uruguay (
(23 specimens additionally to
BOLIVIA • 1; Jansen leg.;
BRAZIL • 1; Matto Grosso (sic!); 1886; P. Germain leg.;
PARAGUAY – Presidente Hayes • 2; Nanawa, “Paraguayan Chaco”; Mar. 1927; G.S. Carter leg.;
URUGUAY – Artigas • 1; 20 km SE Artigas; 30°31'S, 56°22'W; 27 Dec. 2002, S. & J. Peck leg.;
Trox candezei
Harold, 1872: 113 (original description);
Trox (Omorgus) candezei:
Omorgus candezei:
Holotype, by monotypy
(
According to
Argentina (
(15 specimens). ARGENTINA – Buenos Aires • 1; C. Bruch leg.;
Trox ciliatus
Blanchard, 1847: 190 (original description);
Trox (Lagopelus) ciliatus:
Trox (Omorgus) ciliatus:
Omorgus ciliatus:
Omorgus lucidus
Pittino, 2010 (new synonym);
Lectotype
(
“village the Patagones” [=Viedna, Río Negro, Argentina].
of Omorgus (Omorgus) lucidus Pittino, 2010 (new synonym) examined. Holotype, by monotypy (♀ RPMI – Fig.
Omorgus lucidus Pittino, 2010 was described to accommodate a single female specimen closely resembling Omorgus ciliatus (Blanchard, 1847: 190), from “Buenos Ayres” (Argentina) (see
The diagnostic characteristics cited by
During an investigation of many South American and European collections, more than 170 specimens of proper O. ciliatus (according to the description provided by
In conclusion, we found a great variability in O. ciliatus for morphological characters used by
Details of elytra, dorsal habitus and aedeagus of Omorgus ciliatus (Blanchard, 1847): A. Elytral tubercles present and visible (from Catamarca, Argentina); B. Poorly visible (Salta, Argentina) and C. Elytral tubercles absent (Neuquén). Habitus in dorsal view (D–F) of Omorgus ciliatus specimens and their respective aedeagus (G–I) showing no appreciable variation. Scale bars: 1 mm.
Argentina and Bolivia [?]. We have examined only one specimen at
(171 specimens). ARGENTINA – Buenos Aires, • 1; Baía Blanca; C. Bruch leg.;
BOLIVIA [?] – Without further locality • 1;
Omorgus (Omorgus) indigenus
Omorgus indigenus:
Holotype, by original designation
(♂
Paratypes examined
: ECUADOR – Galapagos • 15; Española Is., Bahia Manzanilla; Prosopis grove behind beach; carrion traps; 5–10 Jun. 1985; S. & J. Peck leg.;
Endemic to Galapagos Islands [Ecuador].
(24 specimens). ECUADOR – Galapagos • 3; Española Is., Bahia Manzanilla; 5–10 Jun. 1985; S. & J. Peck leg.;
Trox loxus
Vaurie, 1955: 58 (original description);
Trox (Omorgus) loxus:
Omorgus (Omorgus) loxus:
Omorgus loxus:
Holotype, by original designation
(♀ MCZH). See
Argentina, Brazil, Colombia, Costa Rica, French Guiana, Mexico, Panama, and Paraguay (
(three specimens additionally to
BRAZIL • 1; Matto Grosso (sic!); 1886; P. Germain leg.;
Omorgus (Omorgus) nocheles
Scholtz, 1990: 1412 (original description);
Omorgus nocheles:
Holotype, by original designation
(♂
Omorgus (O.) nocheles is known only from two specimens collected in 1956 in El Bolsón, Argentina (
Trox pastillarius
Blanchard, 1847: 187 (original description);
Trox (Chesas) pastillarius:
Trox (Omorgus) pastillarius:
Omorgus pastillarius:
Omorgus (Omorgus) pastillarius:
Lectotype
(
Argentina, Bolivia, and Chile (
(352 specimens). ARGENTINA – Buenos Aires • 3; Bahía Blanca; 6 Set.– 3 Oct. 1832; C. Darwin leg.;
BOLIVIA • 3;
CHILE • 8;
PARAGUAY – Amambay • 1; P.N. [National Park] Cerro Corá; 30 Mar. 2003; R. Garcés leg.; CVMD.
Trox persuberorus Vaurie, 1962: 145 (original description).
Trox (Omorgus) persuberosus:
Omorgus persuberosus:
Omorgus (Omorgus) persuberosus:
Holotype, by original designation
(♂
Paratypes
. Forty specimens from several localities in different institutions (see
Argentina, Bolivia, Brazil, Paraguay, Peru, and Uruguay (
Trox spatulatus Vaurie, 1962: 151 (original description).
Trox (Omorgus) spatulatus:
Omorgus spatulatus:
Omorgus (Omorgus) spatulatus:
Holotype, by original designation
(♂
Argentina (
(215 specimens). ARGENTINA – Buenos Aires • 1; La Plata; MLPA • 12; Quéquen Puerto; 7 Mar. 1928; M.D. Jurado leg.;
Trox suberosus
Fabricius, 1775: 31 (original description);
Trox (Omorgus) suberosus:
Omorgus suberosus:
Omorgus (Omorgus) suberosus:
For a comprehensive list, see
Neotype, here designated
(♂
Widespread (see below). For details of distribution, see
Neotype designation of Trox suberosus Fabricius, 1775. Trox suberosus was originally described in 1775 by the Danish entomologist Johan Christian Fabricius (1745–1808) based on an unspecified number of specimens collected from “Brasilia” (Latin spelling meaning Brazil) that he had examined in the collection of Sir Joseph Banks (“Mus. Dom. Banks”). The collection is housed currently in The Natural History Museum, London, UK (
Omorgus suberosus is native to the New World and is widely distributed throughout South, Central and North America (from Canada to southern Argentina) (
The ubiquitous New World species has also been recorded from other parts of the world (outside of the New World) such as: Australia, Europe (from Belgium, Czech Republic, Spain), North Africa (from Morocco), Southeast Asia (from the Philippines), and on oceanic islands in the Pacific (Fiji, New Caledonia) and Atlantic (Cape Verde, Canary Islands) (
Omorgus suberosus is also known to be highly opportunistic, and in the absence of carcasses will exploit virtually any other source of keratin (or chitin) present in their environment. This species has been recorded feeding on eggs, dung and chicken feathers in poultry farms in Brazil (
On the compilation of Fabricius types,
Since
In order to establish the single name-bearing type specimen of the widespread Trox suberosus, we propose the designation of a neotype. Our proposed neotype specimen (Fig.
Omorgus triestinae
Pittino, 1987: 378;
Holotype, by original designation
(♂
Paratypes. Same data label of the holotype (11
Bolivia, Brazil, and Paraguay (
Trox (Omorgus) fuliginosus
Robison, 1941: 134 (original description);
Trox fuliginosus:
Omorgus fuliginosus:
Omorgus (Omorgus) fuliginosus:
Omorgus (Omorgus) capillaceus
Scholtz, 1990: 1413 (new synonym):
Holotype, by original designation
(♂ USNM – Fig.
of Omorgus (Omorgus) capillaceus Scholtz, 1990 (new synonym) examined. Holotype, by original designation (♀
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 (
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.
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.
Costa Rica, El Salvador, Guatemala, Mexico, and United States (
(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.
Vinícius da Costa-Silva: Conceptualization, Methodology, Investigation, Resources, Data Curation, Writing - Original draft, Writing - Review and Editing, Visualization, Supervision, Project administration. Werner P. Strümpher: Methodology, Investigation, Resources, Writing - Review and Editing, Supervision. Maxwell V.L. Barclay: Methodology, Investigation, Writing - Review and Editing, Visualization. Fernando Z. Vaz-de-Mello: Investigation, Resources, Writing - Review and Editing, Visualization, Supervision.
The authors thanks Michal Geiser for his help with the literature and catalogues about