Tomarus gyas Erichson 1848
Creators: name: López-García, Margarita M.
name: Deloya, Cuauhtémoc
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Dynastidae
Tomarus
Tomarus gyas

description: Tomarus gyas Erichson, 1848
(Figs. 2I, 3F, 4F, 5G, 6D, 7F, 8J, N, 16F, 19F, 27F; 42)
Tomarus gyas Erichson, 1848: 561. Original combination.
Female lectotype here designated (ZMHB) “27452 / Brit. Guyana / Moritz // Tomarus / Gyas Er. // SYNTYPUS / Tomarus / gyas Erichson, 1848 / labelled by MNHUB 2016 // Tomarus gyas / Erichson, 1848 / LECTOTYPE / Det: M.M. López-García 2016”. Female paralectotype (ZMHB) “ Guyana Moritz // HistColl. (Coleoptera) Nr. 27452 / Tomarus / Gyas Erichs. / Brit. Guyan. / Zool. Mus. Berlin // SYNTYPUS / Tomarus / gyas Erichson, 1848 / labelled by MNHUB 2016”. Female paralectotype (ZMHB) “Hist-Coll. (Coleoptera) Nr. 27452 / Tomarus / Gyas Erichs. / Brit. Guyan. / Zool. Mus. Berlin // SYNTYPUS / Tomarus / gyas Erichson, 1848 / labelled by MNHUB 2016”. Female paralectotype (ZMHB) “Hist-Coll. (Coleoptera) Nr. 27452 / Tomarus / Gyas Erichs. / Brit. Guyan. / Zool. Mus. Berlin // SYNTYPUS / Tomarus / gyas Erichson, 1848 / labelled by MNHUB 2016”. Type locality not explicity mentioned in the original description. Lacordaire (1855) attributed the name of the species to Erichson (1848), who gave the first description even though he had cited it as “ T. gyas Hoffgg. ” (Hoffmannsegg).
Description. Habitus as in Fig. 27F. Length 25.0–29.0 mm; humeral width 13.0– 15.5 mm. Color dark reddish brown to black. Head: Frons and clypeus coarsely and densely rugose. Frontoclypeal region with 2 conical tubercles separated by about 4.5 tubercle diameters. Clypeus narrowed towards apex, base 3 times wider than apex. Clypeal teeth triangular, separated by a tooth diameter. Mandible with 2 apical teeth and a lateral, narrowly rounded tooth (Fig. 5G). Mentum abruptly constricted at apical 3rd. Galea of maxilla with teeth 5 and 6 well developed (Fig. 4F). Interocular distance 3.5 times an eye width. Pronotum: Surface with minute to small punctures, denser and deeper on anterior and posterior angles. Apical tubercle prominent, acute; slightly recurved. Subapical fovea deep, rounded, wide (1/2–2/3 as wide as interocular distance), narrower and shallower in females, surface transversely rugose. Scutellum: Surface with minute, sparse punctures. Elytra: Punctures on first interval as large as those on other intervals. Inner surface of apex with rounded, large tubercles forming 25–30 parallel lines (Fig. 8N). Abdomen: Apex of tergite IV with a triangular wide area with large, rounded tubercles forming 15–17 diagonal parallel lines (Fig. 8J). Pygidium with dense rugosity on basal 3rd, apex rounded. Venter: Apex of prosternal process flat, longitudinally oval to subrectangular. Metasternum with short, sparse setae. Legs: Protibia tridentate, with a basal, small denticle. Apex of metatibia crenulate, with 21–30 spinules. Male genitalia: Spiculum gastrale without basal plates. Phallobase as long as parameres. Parameres with 1 dorsal tooth each side; tooth long, acute; apices triangularly expanded (Figs. 16F, 19F). Internal sac with copulatory lamella and short lamellar spiny belt; with a complex of 5 or 7 spine-like accessory lamellae, with dense granules at base.
Diagnosis. Tomarus gyas is recognized by the following character combination: frontoclypeal tubercles conical; pronotal tubercle acute and prominent (Fig. 27F); pronotal fovea rounded (as wide as interocular distance), smaller in female; metasternum with short setae; protibia tridentate and with an additional basal denticle; apex of metatibia with 21–30 spinules; parameres with a long, acute tooth on each side, apical half strongly narrowed, apices triangularly expanded (Figs. 16F, 19F).
Taxonomic remarks. Tomarus gyas is one of the most problematic species of the genus because of variable taxonomic characters of external morphology and similar shape of the parameres that sometimes make difficult the differentiation with close species, which have been proposed as synonyms by some authors. After the original description by Erichson (1848), Arrow (1914) described T. amazonicus to include specimens from Brazilian Amazonia. However, Endrödi (1969) synonymized it under T. gyas based on the approximate shape of the parameres and difficulty to delimitate the differences on the shape of the pronotal fovea and protibiae. More recently, Escalona & Joly (2006) described T. discrepans, which was differentiated only by the shape of the parameres, but it was not recognized in later works such as Ratcliffe et al. (2013). The present phylogenetic analysis and taxonomic revision shows that T. amazonicus is a valid species not close to T. gyas and differing in several characters, such as the shape of the frontal tubercles, setation on the metasternum, stridulatory apparatus, and internal sac of the aedeagus. Tomarus discrepans, although close to T. gyas, is also a different, valid species.
Distribution. Argentina to Costa Rica. No specimens were examined from Ecuador, but specimens were cited by Endrödi (1969, p. 74) from Guayaquil.
Natural history. Specimens were collected with light traps between 140–2,530 m.
Locality records (Fig. 42). 296 specimens examined from BMNH, CEIOC, CEUN, CTI, FSCA, HJG, ICN, LEUC, MEKRB, MEFLG, MLS, MN/UFRJ, MPUJ, MZUSP, SENASA, UPN, UPTC, UNSM, and USNM. Some records from Neita-Moreno & Ratcliffe (2017). ARGENTINA (40). Buenos Aires (2): Quilmes; San Jacinto. Catamarca (2): Catamarca; El Rodeo. Corrientes (5): Bella Vista; Corrientes; Goya; Rio Paraná. Entre Ríos (2): Concordia; Paraná. Formosa (2): Pilcomayo. Jujuy (2): Jujuy; Parque Nacional Calilegua. La Rioja (1): La Rioja. Río Negro (1): General Roca. Salta (12): Campinchuelo; Coronel Moldes; General Güemes; Hipólito Yrigoyen; Parque Nacional El Rey; Pocitos; Rosario de Lerma; Salta; Vespucio. Santa Fé (6): Rosario de Santa Fé; Santo Tomé. Santiago del Estero (2): Amigo; Santiago del Estero. Tucumán (2): Tucumán. BOLIVIA (19). Beni (1): Cavinas. Chuquisaca (1): Camatindi. La Paz (2): Chulumani; Río Madidi. Santa Cruz (14): Buena Vista; Flor de Oro, Parque Nacional Noel Kempff Mercado; Boyuibe (11 km N); Flora & Fauna Hotel (3.7 km S). Tarija (1): Yacuiba. BRAZIL (115). Bahía (1): Salvador, Canela. Espírito Santo (9): Ribeirão do Engano, Vale do Itauna. Mato Grosso (5): Corumba; Porto Velho, Río Tapirapé; Tres Lagoas. Mina Gerais (4): Cambuquira; Caxambu; Lambary; Passa Quatro. Pará (1): Cachimbo; Mangabeira; Mocajuba. Rio de Janeiro (16): Belem; Campo Grande; Itatiaia; Manguinhos; Passa Tres; Serra dos Orgaos; Teresópolis. Rio Grande do Sul (7): Pelotas; Puerto Alegre; São Leopoldo. Rondônia (16): Ariquemes, near Fazenda Rancho Grande (62 km SW); Cacaulandia, Fazenda Rancho Grande (7 km NE); Ouro Preto do Oeste. São Paulo (51): Angatuba; Atibaia; Barueri; Bofete; Itatiba; Jardim America; Monte Alegre, Fazenda Santa Maria; Piracicaba; Pirassununga; Riberao Preto, Fazenda da Pedra; Riberao Preto; Tieté. Imprecise data (2). South Eastern Part. GUIANA (4). No data (4). COLOMBIA (40). Amazonas (2): Puerto Nariño. Antioquia (7): Medellín. Arauca (7): Arauquita, Campamento Caño Limón. Boyacá (1): Puerto Boyacá. Caldas (2): Manizales, Ecoparque Alcazares. Casanare (2): Aguazul; Yopal. Guaviare (1): Caño Mocuaré. Huila (1): Acevedo. Magdalena (1): Río Frío. Meta (3): Granada; Restrepo; Villavicencio. Nariño (2): Pasto. Norte de Santander (1): Cúcuta. Quindío (1): Quimbaya, Reserva Natural La Montaña del Ocaso. Santander (1): Río Cararé. Tolima (1): Espinal. Vichada (1): Gaviotas. No data (3). COSTA RICA (4). Cartago (1): Turrialba. Heredia (2): La Selva. No data (1). PANAMA (1). Panamá (1): Bayano (2.5 km W Ipiti). PARAGUAY (1). Asunción (1): Asunción. PERU (48). Ayacucho (3): La Mar, Santa Rosa. Cuzco (7): La Convención, Kinteroni. Pilcopata; Estación Biológica Villa Carmen; Quince Mil. Huánuco (3): Tingo María. La Libertad (2): Trujillo, Hacienda Casa Grande. Lima (1): Lima. Madre de Dios (28): Amazonas Lodge (N of Atalaya); Reserva Nacional Tambopata, 30 air km SW Puerto Maldonado. San Martín (3): Huallaga; Moyobamba. No data (1). URUGUAY (51). Colonia (3): Colonia; La Floresta. Maldonado (42): Maldonado; Punta Ballena. Montevideo (6): Colón; Montevideo. VENEZUELA (8). Aragua (3): Maracay. Distrito Capital (5): Caracas.
Natural history. Adults can be collected using lights at night.
description: Published as part of López-García, Margarita M. & Deloya, Cuauhtémoc, 2022, Cladistic analysis reveals polyphyly of Tomarus (Coleoptera: Scarabaeidae: Dynastinae): new classification and taxonomic revision, pp. 1-119 in Zootaxa 5211 (1) on pages 60-62, DOI: 10.11646/zootaxa.5211.1.1, http://zenodo.org/record/7345007