Bothynus quadratus
Creators: name: Duarte, Paulo R. M.
name: Dupuis, Fabien
name: Grossi, Paschoal C.
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Scarabaeidae
Bothynus
Bothynus quadratus

description: Bothynus quadratus
Not examined.
Additional material
ARGENTINA: Buenos Aires: Brandsen, xi.1991 – 1 male, 1 female (FDPC). La Pampa: General Acha, 37°21'29''S, 64°46'60 W, 250 m, 06.xii.2022, Gabriel Lara leg. – 1 male, 1 female (CCZA). Mendoza: Desaguadero, 05.ii.2017, light trap, G. Arriagada Leg. – 1 male, 1 female (CEMT). San Luis: Belgrano, Fundo El Molle, 33°02'22''S, 66°30'47''W, 622 m, light, 07.ii.2017, G. Arriagada – 1 male (CEMT) BRAZIL: Goiás: Mineiros, Parque Nacional das Emas, 27.i.1989, B.B. Santos leg. – 1 male (CERPE); same data but x.1989, B.B. Santos leg. – 1 male (CERPE); São João D’AlianÇa, Chapada dos Veadeiros, Fazenda Sendai, 14.xi.2007, R. M. Koike leg. – 2 males (EPGC). Mato Grosso: Cuiabá, 18.v.1994, A.B. Kênia leg. – 1 males (CEMT); Diamantino, Alto Rio Arinos, 05.xi.1998, E. Furtado leg. – 1 male (CERPE); Diamantino, Alto Rio Arinos, iii.2011, E. Furtado leg. – 1 male (CERPE); Fazenda Vale da Solidão, 21.x.2014, E. Furtado leg. – 1 female (CERPE); Nossa Senhora do Livramento, 25. iii.2017, D.E.M Reis leg. – 1 female (CERPE). Mato Grosso do Sul: Cassilândia: 1.x.2014, C.A. F. Barbosa leg. – 1 male (CERPE); same data but 30.x.2014, C.A.F. Barbosa leg. – 1 male (CERPE). Minas Gerais: Lavras, 18.ix.2005, L. Durães leg. – 1 male (CERPE); same data but 05.x.2008, J.V.C Leitão leg. – 1 male (CERPE). Pará: Belém, Parque Estadual Utinga, xi.2012, F. Silva leg. – 2 females (CERPE). Paraná: Diamante do Norte, 27.xi.2011, Pitfall, M. A. Chermán leg. – 1 male (CERPE); Foz do IguaÇu, 17.xii.2014, luz, R. Barros leg. – 1 male, 1 female (CERPE); Jaguariaíva, Parque Estadual do Cerrado, 18–19.xi. 2009, 800 m, P.C. Grossi leg. – 2 males (CERPE); Palmas, 18.xi.2013, S. Castilho leg. – 1 male (CERPE); Palmas, 1. xii.2013, S. Boese leg. – 1 male (CERPE). Pernambuco: Recife, 15.Viii.2013, E.M.F Morais leg. – 1 male (CERPE). Santa Catarina: 25.v.2012, A. Mozer leg. – 1 male (CERPE). Rio Grande do Sul: Cerro Azul, 1932 – 1 male (CERPE); Porto Alegre, xii.1949. J. Becker – 1 male (CERPE); Santa Rosa, xii.1931, E. Viana leg. – 1 female (CERPE). São Paulo: Serra da Bocaina, Pousada Lageado, 9–10.ii.2016, 1540 m, C.G. Mielke leg. – 1 male (CERPE); Pederneiras, 14. x.2016, luz, M. Bento leg. – 1 male (CERPE). PARAGUAY: Caazapa: xi.1992 – 1 male (FDPC); Concepción: Estancia Cororo, 10–20.iii.2001, luz, C. Aguilar leg. – 7 males (CERPE); Zanja Moroti, 10.x.2004 – 1 male (FDPC). Guaira: Carlos Pfanni, ii.1981 – 1 male (FDPC). Paraguari: PN Ybycui, 21.xi.1989 – 1 male (FDPC); La Colmena, Salto Cristal, 28.xi.2004, 317 m, B. Garcete leg. – 1 male, 1 female (CERPE). URUGUAY: Maldonado: 1924, Barattini leg. – 1 female (CERPE).
Male redescription (Figure 4 (e))
Length: 17.1–25.0 mm. Width: 10.0– 13.1 mm. Colour: Mostly reddish brown; marginal parts of legs and pronotum dark. Head: Clypeus subtriangular, posterior width about 4.0–4.8 times wider than anterior; lateral margins sinuous, constricted towards anterior half; anterior teeth small, conical, about the distance of 2 teeth apart; surface usually glabrous, or with scarce and small setae, nearly entirely rugopunctate, except for rugose disc (Figure 5 (e)). Frontoclypeal carina usually arched, well marked. Frons transversely rugopunctate, glabrous; punctures minute, arranged between wrinkles; posterior region limited by a smooth, transverse area. Interocular width about 3.3–3.5 transverse eye diameters. Mouthparts: Mandibles bearing 3 teeth produced on outer margins (Figure 5 (e, g)); apical and medial teeth triangular; medial tooth wider compared to apical; basal tooth lobed, smaller than previous ones, nearly fused to medial tooth; maxilla bearing 2–3 teeth on apex of galea. Labium subtriangular, surrounded by dense, setigerous punctures; discal region scarcely setose. Antennae: Club subequal in length to antennomeres 2–7 combined. Prothorax: Pronotum usually bearing a small anterior tubercle; cavity rounded, mostly shallow, confined to anterior disc; pronotal surface nearly entirely covered by minute punctures, except for areas close to margins with dense, ocellate, small to large punctures; punctures on anterior corners coalescent to contiguous; punctures close to lateral margins smaller those on anterior corners, separated about 1–4 puncture diameters; cavity rarely rugopunctate or rugose, usually covered with large, deep, transverse, oval punctures. Pterothorax: Scutellar plate subtriangular, usually smooth, sometimes with scarce, minute punctures. Elytra with deep striae covered by small, ocellate punctures; punctures on sutural stria contiguous; punctures on other striae separated by 2–3 puncture diameters; punctures on interstriae mostly minute, small punctures scarce. Legs: Inner protarsal claw simple, equal to outer claw (Figure 11 (l)). Metatarsomere 1 with shortened outer apex. Meso- and metatibia usually bearing only a medial carina produced outer surface. Abdomen: Stridulatory apparatus of tergite 7 usually formed by 1 band of paired, well-marked striae (Figure 19 (b)). Tergite 8 glabrous, rugopunctate on sides and in the middle near anterior margin, disc smooth. Sternites 4–7 moderately rugose on sides, with rugosity becoming fine towards to anterior half of discal region; sternite 7 with a row of setigerous punctures close to posterior margin, usually not reaching the discal region; sternite 8 weakly rugopunctate on corners and on transverse anterior half, posterior half from weakly punctate to smooth, glabrous. Spiculum gastrale: Y-shaped, branches subequal in length; lateral branches separated by U-shaped gap; medial branch rounded apically (Figure 12 (f)). Hemisternite oval, unfused, separated at middle by a narrow, longitudinal membrane, sometimes incomplete; apical margin covered with setae. Aedeagus: Parameres, in dorsal view, smooth, broadly rounded laterally at basal half, strongly constricted lateroventrally towards apical half, apex with 2 rounded, elongate lobes (about 2 times longer than width of own basis) (Figure 13 (q)). Parameres, in lateral view, arched dorsally; ventral area with a deflexed projection subtriangular in shape, basis without carina; apex broadly rounded (Figure 14 (q)).
Female redescription (Figure 16 (f))
Length: 20.0–22.2. Width: 11.9–12.9. Similar to male, except for: tergite 8 flattened in lateral view, bearing an excavation on each side close to posterior margin (Figure 19 (d)), surface glabrous. Sternite 8 parabola-shaped; surface nearly entire rugose, except for a weakly punctate disc; setae confined on posterior margin (Figure 21 (d)).
Distribution
Argentina (Buenos Aires, Entre Rios, La Pampa, Mendoza, San Luis), Brazil (Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais, São Paulo, Pará, Paraná, Pernambuco, Rio Grande do Sul), Paraguay (Concepción, Paraguari), and Uruguay (Maldonado) (Figure 24). Bothynus fabius has the widest distribution among the species of group, occurring from northern Brazil to south-east Argentina. Some adult specimens were collected in the soil at 20 cm depth in General Acha municipality, Argentina (Gabriel Lara, personal communication with PRMD). The species is commonly attracted to light at night and was collected with a‘Luiz de Queiroz’ light trap in a pasture area by Menis and Rodrigues (2021). Furthermore, B. fabius has the characteristic of producing swarms in high populations during the summer in southern Brazil’s natural fields (Grossi et al. 2012).
Remarks
Fairmaire (1878) provided the original description of Scaptophilus fabius, S. striatellus and S. quadratus, in this order. These species appeared in a new combination within the genus Bothynus in Arrow (1937b) (see B. deiphobus remarks). Posteriorly, Endrödi (1969) synonymised B. fabius and B. quadratus under B. striatellus. However, the nomenclatural act performed by Endrödi (1969) was invalid because it disagreed with the principle of priority (Article 23) of the International Code of Zoological Nomenclature (ICZN). Following the order of description presented by Fairmaire (1878), B. fabius should be prioritised over B. striatellus. Although B. striatellus had been the prevailing name for almost a half-century and was used by several authors since Endrödi’s proposition, it does not attain reversal precedence according to article 23.9 of the ICZN. In this case, it should comply with two conditions: (1) the senior synonym or homonym has not been used as a valid name after 1899, and (2) the junior synonym or homonym has been used for a particular taxon, as its presumed valid name, in at least 25 works, published by at least 10 authors in the immediately preceding 50 years and encompassing a span of not less than 10 years. The name B. fabius was used after 1899, so the first condition is not met. Therefore, B. fabius should be revalidated and B. striatellus synonymised under it.
description: Published as part of Duarte, Paulo R. M., Dupuis, Fabien & Grossi, Paschoal C., 2025, Taxonomic revision of the Bothynus ascanius (Kirby, 1819) (Coleoptera: Melolonthidae: Dynastinae) species group, pp. 663-737 in Journal of Natural History 59 (9 - 12) on pages 728-730, DOI: 10.1080/00222933.2025.2456579, http://zenodo.org/record/14971553