Bothynus thrix Hardy, 2017

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 : 731-732

Bothynus thrix Hardy, 2017

( Figures 2k, 10c, 13 (r), 14(r), 16(g), 24)

Bothynus thrix . Hardy 2017: 141 (original description).

Diagnosis

Bothynus thrix is easily recognised among the species of the ascanius group by the following characters: Dorsal surface of the elytra distinctly covered with yellowish setae in both sexes ( Figures 10 (c)). The species resembles B. fabius , but is distinguished by the following characters: Interocular width about 5.5–6.0 times the transverse eye diameter; presence of dorsal setae on body and parameres with elongated and narrow apical plates ( Figure 13 (r)) and presence of a ventrobasal carina ( Figure 14 (r)).

Type material

Holotype male, at Canadian Museun of Ottawa ( CMNC), not examined . Paratype male, labelled: (a) ‘ BOLIVIA: Santa Cruz /5 K ESE Warnes, HOTEL/ Rio Selva, 20–21/X/00/ Morris / Wapes’ ; (b) ‘R .F.Morris/collection’ [blue label]; (c) ‘ PARATYPE ♂ / Bothynus /thryx n.sp./dés. M. Hardy 2017 ’ [yellow label] ( CERPE) ( Figure 2 (k)). Paratypes, one male and one female, labelled: (a) ‘ BOLIVIA: Santa Cruz / Buena Vista / Flora & Fauna Hotel /17-20 .x.00. R. Morris’ ( FDPC) . Paratype female, labelled: ‘ BOLIVIA Santa Cruz /4-6k SSE Buena Vista / F & F Hotel 14–16 Oct ./2000 Wappes & Morris’; (b) ‘ACMT/J. Wappes’; (c) ‘ PARATYPE ♀ / Bothynus /thryx n.sp./dés. M. Hardy 2017 ’ [yellow label] ( CERPE). Holotype not examined.

Additional material

BRAZIL: Mato Grosso, Tangará de Serra , 3–9 .xii .2012, F.V. Mello Leg. – 1 female ( CEMT) .

Male redescription ( Figure 2 (k))

Length: 19.2 mm. Width: 11.1 mm. Colour: Predominantly reddish brown; protibia blackbordered. Head: Clypeus subtriangular (posterior width about 3.6 times wider than anterior), slightly narrow laterally at anterior half; surface weakly rugose, glabrous; anterior teeth small, triangular, pointed. Frontoclypeal carina finely marked. Frontal surface transversely, densely rugose; setae scarce, scattered on sides, separated by a glabrous middle area. Interocular width equals 5.5 transverse eye diameters. Ocular canthus subtriangular, arched on anterior margin. Mouthparts: Mandible bearing apical tooth truncate apically; medial tooth subtriangular, rounded on apex; basal tooth lobed, smaller than previous ones. Maxilla bearing 4 subequal, small teeth arranged on apex of galea. Labium suboval, setose laterally. Antennae: Club subequal in length to antennomeres 2–7 combined. Prothorax: Pronotal anterior tubercle strong, conical; anterior area bearing a wide, rounded, strong declivity, prolonged towards posterior pronotal area. Surface of anterior corners with dense, large, contiguous, setigerous punctures; declivity with large, transverse, oval, setigerous punctures, becoming smaller close to posterior limit of declivity; sides and posterior area close to margins bearing deep, large, setigerous punctures, becoming smaller towards posterior disc. Pterothorax: Scutellar plate parabolic, smooth. Elytral surface bearing yellowish, erect setae ( Figure 10 (c)); striae well marked, covered with small, ocellate punctures, spaced about 2–4 puncture diameters apart. Legs: Inner protarsal claw simple, similar to outer claw. Protibia bearing dorsal surface densely rugopunctate. Mesotibia only with a middle carina produced on outer surface; apex slightly emarginate. Metatibia with 2 carinae on outer surface; apex truncate. Abdomen: Tergite 7 bearing 2 bands of transverse, well-marked striae. Tergite 8 with coarsely rugose, scarcely setose sides; discal area punctate, glabrous; discal punctures large, oval, contiguous. Sternites 4–7 rugopunctate on sides, finely punctate on disc; sternites 5–6 bearing on each side a transverse row of setigerous punctures, disc glabrous; sternite 7 with a complete, transverse row of setigerous punctures; sternite 8 nearly entirely covered with scarce, small punctures, except for the corners with denser punctures; setae confined on posterior margin. Aedeagus: Parameres, in dorsal view, bearing rounded sides at basal half, gradually becoming constricted lateroventrally towards apical half; apical half with elongated, oval lobes ( Figure 13 (r)). Parameres, in lateral view, with convex dorsal surface and apex rounded; ventral surface slightly sinuous, bearing a ventrobasal process ( Figure 14 (r)).

Female redescription ( Figure 16 (g))

Length: 19.0 mm. Width: 10.9 mm. As for the male in overall aspect, except for: Prothorax: Pronotum weakly convex in lateral view; tubercle absent; declivity poorly accentuated; surface nearly completely covered with large, deep, ocellated punctures. Abdomen: Tergite 8 entirely setose. Sternites 4–7 with large, deep, dense punctures; sternite 8 with scarce setae scattered over entire surface, presence of dense, deep, large punctures.

Distribution

Brazil (Mato Grosso) (NEW COUNTRY RECORD) and Bolivia ( Figure 24).

The species was described from eastern areas of Andean and sub-Andean regions of Argentina and Bolivia ( Hardy 2017). The species was collected in Brazil in a transition area among Cerrado and Amazon.

Remarks

The specific epithet was spelled ‘ thryx ’ on the yellow label of the paratypes, instead of ‘thrix’ according to the etymology presented by Hardy (2017). Moreover, the paratypes examined here had labels identifying them as B. striatellus .