Bothynus ascanius
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 ascanius

description: Bothynus ascanius (Kirby, 1819)
(Figures 2 (a), 3(b), 6(a,b), 8(a), 9(a,b), 11(a), 12(a), 13(b), 14(b), 15(b), 17(a,b), 18(a), 19(e), 23)
Scarabaeus ascanius. Kirby 1819: 399 (original combination)
Bothynus ascanius. (Hope 1837): 95 (new combination); (Burmeister 1847: 116) (redescription, misidentification), 573 (name citation); (Lacordaire 1856: 413) (remarks), 414 (name citation); Gemminger and Harold (1869): 1251 (catalogue); Heine and Taschenberg 1908: 93 (name citation, etymology, misidentification), pl. 15 (fig. 3 [illustration]); (Arrow 1911: 156) (remarks); (Prell 1936: 146) (name citation); Arrow 1937b: 40 (catalogue); (Blackwelder 1944: 255) (checklist); Endrödi (1969): 113 (identification key), 117 (figs. 163–164, illustration of aedeagus), 134 (redescription and distribution). Endrödi (1985): 275 (identification key, distribution and illustration of aedeagus [figs. 1126–1128]); Krajcik (2005): 38 (checklist); Abadie et al. (2008): 108 (appendix 1 [distribution]); López-García et al. (2016: 496) (checklist).
Diagnosis
Major specimens of B. ascanius resemble B. laevipennis in the large and robust body, pronotum mostly dark and reddish elytra, besides the pronotal sides surrounded with minute punctures in male. However, B. ascanius is distinguished by the following combination of characters: both sexes with visible elytral punctures; inner protarsal claw incised in male, and presence of a ventroapical process in the protarsomere 5 (Figure 11 (a)); hemisternite fused (Figure 12 (a)); basal half of parameres with broadly rounded sides (Figure 13 (b)); female differs by a shallow and declivous cavity (Figure 17 (a)). Minor specimens of B. ascanius can be also confused with those of B. cylindricus by the small pronotal cavity, small punctures on elytra, and incised inner protarsal claw in male. Despite this, B. ascanius is distinguished by the following combination of characters: Stocky body (Figures 3 (b) and 15(b)) and interocular width equals 3.0–3.5 transverse eye diameters in both sexes; sides of male pronotum covered with minute punctures (Figure 9 (b)); spicullum gastrale with medial branch smaller and broader compared to lateral ones (Figure 12 (a)); female pronotum with no apparent concavity (Figure 17 (a)); pronotal sides with minute to small punctures, separated by 2–3 puncture diameters (Figure 17 (b)).
Type material
Lectotype male, labelled: (a) ‘ Bothynus / ascanius, Kirby /Type/G.J.Arrow det’. [partly handwritten]; (b) ‘TYPE COL: 646/ Scarabaeus / ascanius / Kirby/HOPE DEPT.OXFORD’ [partly handwritten, inscribed in a black border rectangle]; (c) ‘ascanius /K.L.Jr./Brazi’ [handwritten] (OUMNH) (Figure 2 (a)).
Additional material
ARGENTINA: Córdoba: La Cumbre, Km 6, 12.xi.2005, P. Smith leg. – 1 male, 1 female (CERPE). Córdoba: Alpa Corral, 10 km, 8–9.ii.2009, F.C. Ocampo leg. – 1 male (CEMT). BRAZIL: Minas Gerais: Vila Monte Verde, 21.xi.19661. – 1 male (DZUP). Paraná: Guarapuava, 05.x.1986 – 1 male (DZUP); Pinhais, 16.xi.2008, F. Dias leg. – 1 male (CERPE); Piraquara, Mananciais da Serra, 17.x.2007, 1000 m, luz, Grossi and Caron legs. – 1 male (CERPE); Tibagi, Fazenda São Damásio, 04.ii.2008, P. Grossi and Parizotto legs. – 1 male (CERPE). Rio de Janeiro: Itatiaia, iii.2018, Paulo Duarte and Gisele legs. – 1 female (CERPE). Santa Catarina: Urubici, Parque Nacional São Joaquim, 16–19.iii.2012, Grossi, Parizotto and Leivas legs. – 1 male, 1 female (CERPE); no data – 1 male (DZUP). São Paulo: São João do Barreiro, Serra da Bocaina, 9–10.ii.2016, 1540 m, luz, C. G. Mielke leg. – 26 males, 18 females (CERPE); São José do Barreiro, Lajeado, Cachoeira do Paredão, 17. xii.2010, L. L. Dumas and J. L. Nessimian legs. – 3 males (CEMT).
Male redescription (Figure 3 (b))
Length: 20.5–30.8 mm. Width: 10.9–21.1 mm. Colour: Head, pronotum, tibiae and tarsi dark; other parts dark reddish. Head: Clypeus subtrapezoidal (posterior from 2.7–3.0 times wider than anterior); lateral margins regularly convergent; anterior teeth transverse, usually lobed (Figure 6 (a,b)); surface coarsely rugopunctate, glabrous. Frontoclypeal carina strongly marked. Frons coarsely rugose, scarcely setose. Interocular width equals 3.0–3.5 transverse eye diameters. Mouthparts: Mandibular outer margin bearing 3 teeth; apical and medial teeth strong, flattened, transversely arranged, slightly back produced, separated by a deep notch; apical tooth usually obliquely truncated; medial and basal teeth lobed; basal tooth smaller than other ones. Maxillary galea with 3 pointed teeth arranged on apex (Figure 7 (b)). Maxillary palpomere 4 oval, slightly flattened dorsoventrally, bearing a broad sensorial spot produced to apical half. Labium subtriangular. Antennae: Club nearly 1.8 times longer than antennomeres 3–7 combined. Prothorax: Pronotal anterior tubercle strong, conical, sometimes rounded apically; cavity broadly rounded, deep in major males (Figure 8 (a)), shallow and narrow in minor males; lateral margins poorly visible, nearly completely hidden by the lateral edges of pronotum; cavity surface transversely rugose; lateral area near margins with large, deep, contiguous punctures, becoming minute to posterior disc (Figure 9 (a, b)); transverse area near posterior margin with large, coalescent, C-shaped punctures. Pterothorax: Scutellar plate usually smooth, rarely with scarce punctures. Elytral striae shallow, covered by small, ocellate punctures, separated by about 1–2 puncture diameters; interstriae with punctures from minute to small, irregularly scattered. Metaventrite densely setose. Legs: Inner protarsal claw deeply incised, with outer branch narrower and more pointed than inner one (Figure 11 (a)). Tarsomere 5 with a small, triangular, subapical, ventrolateral process. Abdomen: Tergite 7 with stridulatory apparatus formed by 1 band of numerous, transverse, barely marked striae confined on discal area. Tergite 8 slightly emarginate on anterior margin; surface densely rugopunctate on sides, with disc weakly punctate; setae scarce, transversely scattered on an area close to posterior margin. Sternites 4–7 with rugopunctate and dense setae on sides, disc with small setigerous punctures; sternite 8 densely punctate, glabrous, with setae confined on posterior margin. Spiculum gastrale: Y-shaped; medial branch widely triangular at basis, shorter compared to lateral branches, rounded at apex (Figure 12 (a)). Hemisternite in shape of an inverted triangle, with a transverse row of numerous setae on apical margin (Figure 12 (a)). Aedeagus: Parameres, in caudal view, rounded laterally at basal half, strongly constricted lateroventrally at apical half; apical plates elongated, oval (Figure 13 (b)); surface densely covered by longitudinal punctures at basal half, bearing numerous small tubercles irregularly arranged at sides of apical half. Parameres, in lateral view, arched dorsally, bearing a ventrobasal process, subapical surface deeply excavated, apex rounded (Figure 14 (b)).
Female description (Figure 15 (b))
Body length: 22.7–29.6 mm: Body width: 13.0– 16.5 mm. Female is similar to male, except in the following aspects: Prothorax: Pronotum weakly rounded laterally compared to male; anterior tubercle small or obsolete; cavity shallow, declivous, transversely rugose or rugopunctate on tubercle basis, bearing dense, large, deep, contiguous punctures towards posterior area; anterior pronotal corners densely rugopunctate; posterior sides covered by dense, large punctures on an area close to margins, becoming smaller, sparser about 2–3 puncture diameters apart towards disc; punctures on disc minute (Figure 17 (a,b)). Legs: Inner protarsal claw usually simple, rarely with a small, ventromedial lobe. Protarsomere 5 with no ventroapical process. Metafemur with ventral surface covered with deep, oval punctures; punctures spaced about 3–5 puncture diameters apart (Figure 18 (a)). Abdomen: Tergite 8 nearly entirely covered by setae (Figure 19 (e)). Sternite 8 weakly setose on discal area.
Distribution
Argentina (Córdoba) and Brazil (Minas Gerais, Paraná, Rio de Janeiro, Santa Catarina and São Paulo) (Figure 23). Historically, the distribution of B. ascanius was known only from Rio Grande do Sul state, South Brazil (Endrödi 1985; Abadie et al. 2008). Recently, Ratcliffe et al. (2023) provided records of B. ascanius from Argentina and Paraguay.
Remarks
Hope (1837) described Bothynus and included two species in this genus: Geotrupes cuniculus Fabricius 1801 [currently Anagrylius cuniculus (Fabricius, 1801) (see Lópes-García and Deloya 2022) and Scarabaeus ascanius Kirby, (1819) (currently B. ascanius)]. In his description, Hope (1837) designed G. cuniculus as the type species of Bothynus. Posteriorly, Burmeister (1847) presented the description of B. ascanius based on two misidentified specimens that indeed are the current Bothynus medon (Germar 1824). Subsequently, Lacordaire (1856) considered G. cuniculus an indeterminable species and ttha B. ascanius should be the type species of the genus instead. However, Lacordaire considered the false B. ascanius presented by Burmeister to be the type, leading to posterior confusion about the true B. ascanius, such as that observed in Heyne and Taschenberg (1908) (pl. 15, fig. 3), whose illustrated species is clearly a B. medon presented as B. ascanius. Arrow (1911) noticed this confusion after accessing the type specimen of the true B. ascanius preserved at OUMNH and provided remarks about it. Finally, Endrödi (1969) examined the two Burmeister specimens and mistakenly labelled these as type specimens of B. ascanius.
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 671-675, DOI: 10.1080/00222933.2025.2456579, http://zenodo.org/record/14971553