Bothynus tricornis Arrow, 1937

Duarte, Paulo R. M. & Grossi, Paschoal C., 2020, Bothynus entellus (LePeletier & Serville) (Coleoptera: Scarabaeidae: Dynastinae) species group: taxonomic revision and description of two new species, Zootaxa 4750 (1), pp. 101-121 : 107-108

publication ID	https://doi.org/ 10.11646/zootaxa.4750.1.5
publication LSID	lsid:zoobank.org:pub:1A3B7CFF-292B-46AB-82E8-C78BA34618EC
DOI	https://doi.org/10.5281/zenodo.3706205
persistent identifier	https://treatment.plazi.org/id/03E31B7A-5904-FFA3-FF6C-F8FABC41FD49
treatment provided by	Plazi
scientific name	Bothynus tricornis Arrow, 1937
status

Treatment

( Figs. 3 View FIGURE 3 A–E; 8C; 9C; 10C; 11C;12C)

Bothynus tricornis Arrow 1937: 45 (original description).

Diagnosis. Bothynus tricornis is distinguished from other species of the group by the following combination of characters: major and median males with three remarkable pronotal horns ( Fig. 3 View FIGURE 3 A–B); three tubercles instead horns in minors ( Fig. 3C View FIGURE 3 ); pronotal concavity extremely deep ( Fig. 3 View FIGURE 3 A– C); hypomeron emarginate in ventral view ( Fig. 3E View FIGURE 3 ); parameres with rounded basal half and apical half with lateral flaps gradually expanded toward apex ( Fig. 8C View FIGURE 8 ); female differs from other females of group by the pronotal concavity densely covered by coalescent punctures ( Fig. 10C View FIGURE 10 ); tergite VIII with apical invagination strongly emarginate and transverse about 7.9 times wider than long ( Fig. 11C View FIGURE 11 ).

Type material. Holotype male, Bothynus tricornis Arrow, 1937 : examined ( NHM). Labeled: “ Brazil: Sabara- Bello [Sabará-Belo] Horizonte, Rio das Velhao [Velhas], A.G.N.Chalmers, B.M. 1932-II. ”

Additional material examined. 6 males and 3 females. Brasil: Minas Gerais: Mirandópolis, Taiobeiras , XI.2014, R. Koike— 4♂ 2♀ ( CERPE); Perdões , 12.X.2006, F. Campos— 1♂ ( EPGC); Passos , 24.X.1963 C. Elias— 1♀ ( DZUP). Rio de Janeiro: Teresópolis , no date, P. Schirch— 1♂ ( MNRJ) .

Redescription. Male. Body length: 25.0– 30.1 mm. Body width: 11.0–13.0 mm. Color: Completely dark ( Fig. 3 View FIGURE 3 A–C). Head: Clypeus subpentagonal, moderately arched at middle, surface densely rugopunctate, with scarce setae on sides, apical half strongly constricted laterally, basal half with subparallel raised sides. Frontoclypeal suture with 2 strong, slender tubercles. Interocular width equals 2.4 transverse eye diameters; frontal surface densely rugopunctate, setose on sides. Eye canthus subtriangular. Mouthparts: Mandibles bidentate, teeth conic, strong. Maxilla with quadridentate galea; 1 strong tooth at apex, apical, 3 moderate teeth at base. Pronotum: Horned, with 3 remarkable upcurved horns (1 horn on each side, 1 horn on apex); concavity strongly deep, broad, occupying about ½ of pronotal area. Major males with bifurcated horns; apical horn exceeding the head length, covering it partially in dorsal view ( Fig. 3A View FIGURE 3 ). Median males with weak apical bifurcation; apical horn not exceeding the head length ( Fig. 3B View FIGURE 3 ). Minor males with pronotal tubercles instead of horns ( Fig. 3C View FIGURE 3 ). Pronotal surface finely punctate, with few setae scattered on anterior area; anterior angles strongly constricted in frontal view. Scutellar shield: From parabolic to subtriangular. Elytra: Nearly completely smooth, striae barely marked, punctures only observed under 90X magnification. Venter: Hypomeron strongly emarginate in ventral view ( Fig. 3E View FIGURE 3 ). Legs: Metatibia with spatulate internal spur. Abdomen: Ventrites I–II completely setose, III–IV with an incomplete row of setose punctures, V with a complete row of punctures, VI bordered with long setae on apex. Stridulatory apparatus of tergite VII with 2 bands of finely carinae, interrupted by a mid-line nearly reaching the apical margin. Tergite VIII rugopunctate on sides, discal area weakly punctate or smooth. Aedeagus: Parameres in caudal view ( Fig. 8C View FIGURE 8 ), basal half with rounded outer sides, middle area strongly constricted on sides, apical half with divergent lateral flaps. In lateral view, apex downcurved, obtuse ( Fig. 9C View FIGURE 9 ).

Female ( Fig. 3D View FIGURE 3 ). Body length: 23.8–27.1 mm. Body width: 14.5–15.0 mm. Female differs from male in the following aspects: Head: Frons with slightly convex basal area. Pronotum: Simple convex, anteriorly with a small apical tubercle followed by a shallow concavity confined to anterior area; anterior angles densely punctate; concavity densely covered with coalescent punctures ( Fig. 10C View FIGURE 10 ); discal area moderately punctate. Legs: Inner protarsal claw simple, similar to outer claw. Abdomen: Ventrite VI triangular. Tergite VIII with subtrapezoidal shaped apical invagination, transverse about 7.9 times wider than long ( Fig. 11C View FIGURE 11 ).

Geographic distribution: Brazil: Minas Gerais, Rio de Janeiro ( Fig. 12C View FIGURE 12 ). Bothynus tricornis occurs in transitional areas between Atlantic rainforest and Cerrado, with some occurrence from the Brazilian Atlantic coastal rainforest. It is apparently a rare species, which has not been collected nor registered in literature since Endrödi (1969, 1985) (who also cited records from the states of Espírito Santo and Santa Catarina). Recently a population was found in the north of Minas Gerais.