Bothynus robustus Duarte, Dupuis and Grossi, 2025

Bothynus robustus Duarte, Dupuis and Grossi sp. n.

( Figures 4 View Figure 4 (a), 8(d), 11(j), 13(m), 14(m), 23)

Diagnosis

Bothynus robustus sp. n. is a large species (31.5 mm) that resembles B. nyx in the pronotum with deep, oval and transverse cavity, besides the striated elytra, and elongated parameres. However, B. robustus is easily separated by the following characters: Inner protarsal claw incised, combined with the presence of a ventroapical process at protarsomere 5 ( Figure 11 View Figure 11 (j)); outer sides of parameres constricted on apical half just behind the apical lobe in caudal view ( Figure 13 View Figure 13 (m)); apex of parameres rounded in lateral view ( Figure 14 View Figure 14 (m)). The male of B. nyx instead bears the inner protarsal claw without incision, provided only with a ventromedial process (similar to those of B. laevipennis [ Figure 11h View Figure 11 ], and the protarsomere 5 lacks the ventroapical process. Moreover, the apical half of parameres is nearly parallel in caudal view ( Figure 13 View Figure 13 (k)), with no lateral constriction, and the apex is pointed in lateral view ( Figure 14 View Figure 14 (k)).

Holotype Male, dissected, labelled: ‘ BRASIL: Mato Grosso: Barra do Bugres, Vão Grande , 31.xii.2011, J. Esteves leg’. ( CERPE).

Paratype One male, labelled: ‘ ARGENTINA: Asconchinga, Sierra de Cordoba N, 750 m, 08– 09.01 .2011, V. May Leg’. ( FDPC).

Holotype description ( Figure 4 View Figure 4 (a))

Length: 31.5 mm. Width: 18.2 mm. Colour: Nearly entirely dark reddish brown. Head: Clypeus subtrapezoidal (posterior width about 2.7 times wider than anterior), coarsely rugopunctate, glabrous. Frontoclypeal carina slightly notched emarginated at middle. Frons coarsely rugose, glabrous. Interocular width equals 3.5 transverse eye diameters. Ocular canthus subtriangular; anterior margins arched. Mouthparts: Mandible with lobed teeth (possibly abrased). Labium suboval, densely surrounded with large, deep, contiguous, setigerous punctures; discal region with scarce setae, shorter those on sides. Antennae: Club 2.0 times longer than antennomeres 2–7 combined. Prothorax: Pronotal anterior tubercle strong, rounded apicaly, raised above a transverse edge; cavity wide (occupying 2/3 of anterior pronotal area), oval, transverse, deep, posteriorly limited by 2 small, rounded tubercles ( Figure 8 View Figure 8 (d)); punctures on anterior corners dense, deep, coalescent; punctures on sides shallow, moderated compared those on anterior corners, scattered about 3 puncture diameters; posterior area close to margin strongly rugopunctate; posterior disc weakly punctate; cavity transversely rugose. Pterothorax: Scutellar plate parabolic; disc with 8 irregularly scattered punctures (5 large, deep, setigerous; 3 small, shallow). Elytral striae well marked; punctures large, dense, deep, ocellated, from contiguous to separated by 1 puncture diameter on sutural stria; punctures on other striae separated by 2 puncture diameters; interstriae with irregular punctures. Legs: Inner protarsal claw incised; branches subequal ( Figure 11 View Figure 11 (j)). Protarsomere 5 with a small, ventroapical process. Meso- and metatibia with 2 carinae produced on outer surface. Abdomen: Tergite 7 with stridulatory apparatus formed by 1 band of numerous, finely marked striae. Tergite 8 completely covered with strongly rugosity, scarcely covered with short setae. Sternites 4–7 densely rugopunctate on sides, with an incomplete row of setose punctures, disc finely punctate and glabrous; sternite 8 glabrous, nearly completely rugopunctate, except for a weakly punctate area close to posterior margin. Aedeagus: Parameres, in caudal view, elongated, finely punctate, laterally subparallel on basal half, abruptly constricted lateroventrally on apical half ( Figure 13 View Figure 13 (m)); apical lobes oval. Parameres, in lateral view, convex dorsally, ventral surface with a weak carina at basis, apex rounded ( Figure 14 View Figure 14 (m)).

Female

Unknown

Variation in the paratype

The paratype does not vary significantly concerning the holotype.

Distribution

Known from central Brazil (Mato Grosso) and Argentina (Asconchinga) ( Figure 23 View Figure 23 ).

Etymology

The specific epithet derives from the Latin ‘ Röbur ’ meaning a kind of strength or hardness, plus the suffix ‘ tus ’ meaning ‘provided with’, in reference to the hard appearance of the body. The name is an adjective in the nominative singular.