Bothynus cylindricus Arrow, 1937a

Duarte, Paulo R. M., Dupuis, Fabien & Grossi, Paschoal C., 2025, Taxonomic revision of the Bothynus ascanius (Kirby, 1819) (Coleoptera: Melolonthidae: Dynastinae) species group, Journal of Natural History 59 (9 - 12), pp. 663-737 : 692-697

Bothynus cylindricus Arrow, 1937a

( Figures 2 (d), 3(e), 8(b), 9(c,d), 11(c,d), 13(e,s), 14(e), 15(f), 16(h), 18(c), 21(b), 22)

Bothynus cylindricus

Arrow 1937a: 45 (original description); Arrow 1937b: 40 (catalogue); Blackwelder 1944: 244 (checklist); Endrödi 1969: 113 (identification key), 117 (illustration of the aedeagus [figs. 165–167]), 135 (diagnosis, distribution); Endrödi 1985: 276 (illustration of the aedeagus [figs. 1132–133], identification key, distribution). Krajcik 2005: 38 (checklist); Abadie et al. 2008, pl. 13 (dorsal habitus [ Figure 5 ], distribution). López-García et al. 2016: 496 (checklist).

Diagnosis

Bothynus cylindricus resembles B. laticifex but the former is distinguished by the following combination of characters: Posterior region of the prontal concavity interrupted at middle ( Figure 9 (c)); posterior corners of the male pronotum strongly rugopunctate or rugose ( Figure 9 (d)); inner protarsal claw of male with elongated outer branch, surpassing the basal half of the inner one in length ( Figure 11 (c)); dorsal surface of parameres covered with well-impressed punctures ( Figure 13 (e)); basal sides of parameres with constricted sides in frontal view ( Figure 13 (s)). Bothynus cylindricus also can be confused with minor specimens of B. ascanius , but B. cylindricus can be separated by the following characters: Interocular width about 4.1–4.4 transverse eye diameter in both sexes; male pronotum with cavity interrupted at middle of posterior edge ( Figure 9 (c)) in both sexes; large and dense punctures on the sides of male pronotum ( Figure 9 (c, d)); spiculum gastrale with subequal branches ( Figure 12 (c)).

Type material

Lectotype male, here designated, labelled: (a) ‘ SYN- /TYPE’ [rounded label, bordered in blue]; (b) ‘Type’ [rounded label, bordered in red]; (c) ‘Minas/Brasil’ [handwritten]; (d) ‘67.45’ [handwritten]; (e) ‘686’. [handwritten]; (f) ‘Columbus/[illegible]/Brasilia’ [handwritten]; (g) Bothynus / cylindricus /type arrow” [handwritten] ( NHM) ( Figure 2 (d)). Paralectotype female, here designated, labelled: (a) ‘SYN/TYPE’ [rounded label, bordered in blue]; (b) ‘Fry/Rio Jan’. [handwritten]; (c) ‘Fry. Coll/1905.100’. [handwritten] ( NHM).

Additional material

ARGENTINA: Misiones: 22.i.1995, R. Foester leg. – 1 male ( CERPE) . BRAZIL: Distrito Federal: Brasília , Embrapa HortaliÇas, 3–8.xi.2016, N. G. Souza leg. – 1 male ( CERPE) . Goiás: Cristalina, Fazenda Larga Grande , 30.i.2017 / 3–8.xi.2017, luz, N. G. Souza leg. – 2 females ( CERPE); Planaltina, Embrapa Cerrado , 26.vii.2005, C. Oliveira leg. – 1 male ( CEMT) . Minas Gerais: Lavras, 05.viii.1999, M. Sampaio leg. – 1 male ( CERPE); Lavras, 19.viii.2006, luz, G.A. Souza leg. – 1 female ( CERPE) . São Paulo: Lins , Fazenda Santa Clara, 19.ix.1981, luz, L. Evandro leg. – 1 male ( CEMT) . Rio Grande do Sul: Frederico Westphalen, Vila Faguense, 14.i.2005, Sponchiado, V.E.C. – 1 male ( CEMT) .

Male redescription ( Figure 3 (e))

Length: 19.0–20.0 mm. Width: 10.6–11.0 mm. Colour: Reddish brown in overall aspect; pronotum, meso- and metatibia sometimes dark reddish brown. Head: Clypeus subtriangular (posterior width about 3.2–3.8 times wider than anterior); lateral margins evenly convergent; anterior teeth from subtriangular to lobed, usually with rounded apex; surface glabrous, strongly rugose. Frontoclypeal carina well marked, slightly arched in frontal view. Frons strongly rugose, bearing minute punctures between wrinkles; setae scarce, arranged on sides; discal area glabrous; interocular width equals 4.1–4.4 transverse eye diameters. Ocular canthus transverse, usually subrectangular, bearing arched anterior margin. Mouthparts: Mandible with apical and medial teeth subtriangular, basal tooth lobed; apical tooth diagonally truncated on apex. Labium subtriangular, slightly rounded laterally; sides setose, disc weakly rugose. Prothorax: Pronotum with anterior tubercle small, conical, rounded apically; cavity small, rounded, shallow confined on anterior disc ( Figure 8 (b)); posterior limit of cavity interrupted at middle in laterodorsal view ( Figure 9 (c)); pronotal sides with dense, large, contiguous punctures, coalescent near margins; posterior disc with minute punctures; transverse area close to posterior margin from rugopunctate to rugose ( Figure 9 (d)); cavity nearly entirely rugose, except for the posterior limit covered with large, transverse, C-shaped punctures. Pterothorax: Elytral surface with well-marked striae, covered with small, ocellate punctures; punctures contiguous on sutural stria, from contiguous to 1 puncture diameter apart on other striae; interstriae with minute punctures. Legs: Inner protarsal bent downward nearly 90° ( Figure 11 (d); outer branch acute, elongated, surpassing the basal half of the inner one in length ( Figure 11 (c)); inner branch broader compared to outer one. Protarsomere 5 bearing a triangular, subapical, ventral process. Mesofemora with glabrous ventral disc. Meso- and metatibiae only with a middle carina. Abdomen: Tergite 7 with stridulatory apparatus formed by 1 band of numerous finely marked, transverse striae. Tergite 8 glabrous, rugose on sides and a transverse area close to anterior margin, disc with shallow, transverse punctures. Sternites 4–7 with moderately punctate and weakly setose sides, discal area smooth; sternite 8 bearing smooth disc, sides weakly rugopunctate. Spiculum gastrale : Y-shaped; branches subequal in length; medial branch narrow at basis ( Figure 12 (c)). Hemisternite in shape of an inverted, transverse triangle; apical margin bearing 5–7 setae on apical margin. Aedeagus: Parameres, in caudal view, rugopunctate; basal half rhomboid-shaped; apical half strongly constricted lateroventrally; apical lobes broad rounded ( Figure 13 (e)). Parameres, in frontal view, with narrow basal sides ( Figure 13 (m)). Parameres, in lateral view ( Figure 14 (e)), ventrally with a small carina at basis; apex weakly deflexed; subapical area behind lobe strongly depressed.

Female description ( Figure 15 (f))

Length: 19.0– 19.2 mm. Width: 10.8–11.0 mm. As for the male, except for the following aspects: Prothorax: Pronotal surface nearly entirely covered with dense, large, deep, ocellate punctures; punctures on posterior sides separated by about 1–2 puncture diameters; tubercle very small or obsolete; cavity shallow. Legs: Inner protarsal claw simple, similar to outer claw. Tarsomere 5 with no ventral process. Abdomen: Sternite 8 nearly entirely rugose, with moderated setae transversely arranged ( Figure 21 (b)).

Distribution

Argentina (Córdoba) and Brazil (Distrito Federal, Minas Gerais, Rio Grande do Sul and São Paulo) ( Figure 22 ). There are records from Paraguay in Ratcliffe et al. (2023).

Remarks

Arrow (1937a) described B. cylindricus based on two specimens (one of each sex) and provided the diagnosis by comparing it with B. laticfex and B. cribrarius . Endrödi (1969) did not examine the type specimens of B. cylindricus and provided a short diagnosis comparing it with B. ascanius . Despite his information on the high similarity among B. ascanius and B. cylindricus , however, these two species can be distinguished by the new diagnostic characters provided here.

Figures

Figure 2. Types,with their respective labels on the right: (a) Bothynus ascanius (Kirby,1819); (b) Bothynus cribrarius (Fairmaire, 1878); (c) Bothynus cyclops (Burmeister, 1847); (d) Bothynus cylindricus Arrow, 1937; (e) Bothynus deiphobus (Burmeister, 1847); (f) Bothynus laevipennis Arrow, 1937; (g) Bothynus laticifex Burmeister, 1847; (h) Bothynus minor Steinheil, 1872; (i) Bothynus nyx Ratcliffe, 2010; (j) Bothynus fabius (Fairmaire, 1878); (k) Bothynus thrix Hardy, 2017.

Figure 3. Male dorsal habitus: (a) Bothynus arriagadae sp. n.; (b) Bothynus ascanius; (c) Bothynus cribrarius; (d) Bothynus cyclops; (e) Bothynus cylindricus; (f) Bothynus deiphobus; (g) Bothynus gisae sp. n.; (h) Bothynus laevipennis; (i) Bothynus laticifex; (j) Bothynus minor; (k) Bothynus nyx; (l) Bothynus ovalatus sp. n.

Figure 5. Dorsal view of clypeus and mandibular teeth (a–e), lateral view of clypeus and left mandible (f, g): (a) Bothynus bentoi sp.n.; (b, f) Bothynus cyclops; (c) Bothynus minor; (d) Bothynus ovalatus sp. n.; (e, g) Bothynus fabius. at = apical tooth, mt = medial tooth, bt = basal tooth, mp4 = maxillary palpomere 4.

Figure 8. Dorsal view of male pronotum: (a) Bothynus ascanius; (b) Bothynus cylindricus; (c) Bothynus nyx; (d) Bothynus robustus sp. n. pc = pronotal cavity.

Figure 9. Laterodorsal view of male pronotum (a, c, e, g, i, k), detail of the posterior sides (b, d, f, h, j, l): (a, b) Bothynus ascanius; (c, d) Bothynus cylindricus (black arrow points to posterior marginal rugosity); (e, f) Bothynus laevipennis; (g, h) Bothynus laticifex; (i, j) Bothynus nyx; (k, l) Bothynus rufipennis sp. n.

Figure 11. Inner view of the male protarsomere 5 and respective claws (a, b, d, e, g – i), frontal view of the male protarsal claws (c, f): (a) Bothynus ascanius; (b) Bothynus cyclops; (c, d) Bothynus cylindricus; (e, f) Bothynus laticifex; (g) Bothynus gisae sp. n.; (h) Bothyhus laevipennis; (i) Bothynus ovalatus sp. n.; (j) Bothynus robustus sp. n.; (k) Bothynus sapukai sp. n.; (l) Bothynus fabius. Black arrows indicate the inner branch of the inner protarsal claw. ipc = inner protarsal claw, opc = outer protarsal claw, pt5 = protarsomere 5, vap = ventroapical process, vmp = ventromedial process.

Figure 12. Spiculum gastrale: (a) Bothynus ascanius; (b) Bothynus cyclops; (c) Bothynus cylindricus; (d) Bothynus deiphobus; (e) Bothynus laevipennis; (f) Bothynus fabius. hs = hemisternite.

Figure 13. Parameres in caudal (a–r) and frontal views (s, t): (a) Bothynus arriagadae sp. n.; (b) Bothynus ascanius; (c) Bothynus cribrarius; (d) Bothynus cyclops; (e, s) Bothynus cylindricus (arrows point to basal constriction); (f) Bothynus deiphobus; (g) Bothynus gisae sp. n.; (h) Bothynus laevipennis; (i, t) Bothynus laticifex; (j) Bothynus minor; (k) Bothynus nyx; (l) Bothynus ovalatus sp. n. (arrows point to contiguous basis of the apical lobes); (m) Bothynus robustus sp. n.; (n) Bothynus rufipennis sp. n.; (o) Bothynus sapukai sp. n. (arrows point to the basal separation of the apical lobe); (p) Bothynus scutellopunctatus sp. n.; (q) Bothynus fabius; (r) Bothynus thrix. al = apical lobe.

Figure 14. Parameres in lateral view: (a) Bothynus arriagadae sp. n.; (b) Bothynus ascanius; (c) Bothynus cribrarius; (d) Bothynus cyclops; (e) Bothynus cylindricus; (f) Bothynus deiphobus; (g) Bothynus gisae sp. n.; (h)Bothynus laevipennis;(i)Bothynus laticifex;(j) Bothynusminor; (k)Bothynus nyx;(l)Bothynus ovalatus sp.n.; (m) Bothynus robustus sp. n.; (n) Bothynus rufipennis sp. n.; (o) Bothynus sapukai sp. n.; (p) Bothynus scutellopunctatus sp. n.; (q) Bothynus fabius; (r) Bothynus thrix.

Figure 15. Female dorsal habitus: (a) Bothynus arriagadae sp. n.; (b) Bothynus ascanius; (c) Bothynus bentoi sp. n.; (d) Bothynus cribrarius; (e) Bothynus cyclops; (f) Bothynus cylindricus; (g) Bothynus deiphobus; (h) Bothynus gisae sp. n.; (i) Bothynus laevipennis; (j) Bothynus laticifex; (k) Bothynus minor; (l) Bothynus Moroni sp. n.

Figure 21. Sternites 4–8 of females (a–d): (a) Bothynus bentoi sp. n.; (b) Bothynus cylindricus; (c) Bothynus rufipennis sp. n.; (d) Bothynus fabius. st = sternite.

Figure 22. Known geographical distribution of Bothynus arriagadae sp. n., Bothynus cylindricus, Bothynus laticifex, Bothynus ovalatus sp. n., Bothynus rufipennis sp. n., and Bothynus sapukai sp. n.