Bothynus nyx Ratcliffe, 2010

(Figures 2i, 3k, 8c, 9i, j, 10b, 13k, 14k, 16a, 17g, h, 23)

Bothynus nyx

Ratcliffe 2010: 105 (original description); López-García et al. 2016: 497 (checklist).

Diagnosis

Bothynus nyx is a large species (32.5–34.5 in length) that is distinguished from other species of the ascanius group by the following combination of characters: Both sexes bearing pronotum with a transverse, deep and oval cavity (Figure 8 (c)), besides the elytra with small punctures (Figures 10 (b)); inner protarsal claw of males only with a ventromedial process; apical half of parameres with parallel sides in caudal view (Figure 13 (k)), combined to sharply apex in lateral view (Figure 14 (k)). Bothynus nyx is comparable to B. laevipennis in the males with large and deep pronotal cavity, besides the inner protarsal claw only with a ventromedial process along tarsomere 5 without a ventral process.

Type material

Holotype male, labelled: (a) ‘ BOLIVIA: Dep. Santa Cruz / Bermejo, Refugio Los Volcanes / Hotel area, 18°06'18''S 63°35'54''W / 09.xii.2003, at night/coll D.J. Mann and A.C. Hamel’; (b) ‘OUMNH-2004-005/ D.J.Mann and C.Hamel coll./ Pres. Mann and Hamel, 2004’; (c) ‘ BOTHYNUS /NYX/RATCLIFFE/HOLOTYPE’ [red label, partly handwritten] (OUMNH) (Figure 2 (i)).

Additional material

BOLIVIA: Caranavi: iv .2008 – 1 male, 1 female (FDPC) . La Paz: Coroico, 22.i.2009 – 1 male, 1 female (EPGC).

Male redescription (Figure 3 (k))

Length: 32.5–34.5 mm. Width: 17.8–18.0 mm. Colour: Head, pronotum, tibiae and tarsi dark reddish-brown; elytra and ventral surface reddish brown. Head: Clypeus subtrapezoidal (posterior width about 3.0–3.1 times wider than anterior one); lateral margins sinuous, slightly constricted at anterior half, subparallel at posterior half; anterior teeth usually lobed, transverse; surface transversely rugose, glabrous. Frontoclypeal carina well marked, slightly sinuous, nearly reaching the lateral margins. Frontal surface transversely covered with strong rugosity; setae scarce, arranged on sides close to eyes; middle area glabrous. Interocular width equals 3.4–3.8 transverse eye diameters. Ocular canthus transverse, arched. Mouthparts: Mandible with apical tooth diagonally truncate apically; medial tooth with broadly lobed apex, larger than apical one; basal tooth rounded, smaller than previous ones. Labium suboval, flattened, surrounded with dense, large, deep, setigerous punctures; disc weakly rugose, with scarce setae. Antennae: Club flattened, broad, about 1.6 times larger than antennomeres 2–7 combined. Prothorax: Pronotal anterior tubercle strong, conical, raised on a transverse edge; cavity deep, wide (occupying over 1/2 of anterior area), transverse, oval (Figure 8 (c)), sometimes limited posteriorly by a small tubercle. Pronotal cavity transversely rugose, limited laterally with small, scarce punctures; anterior pronotal corners with large, deep, from contiguous to coalescent; pronotal sides covered with minute or small punctures (Figure 9 (i,j)), except for an area close to lateral margins with dense, small punctures; punctures minute on posterior area behind cavity, becoming large, dense, coalescent, rugose towards posterior margin. Pterothorax: Scutellar plate finely punctate. Elytral striae barely marked, covered with ocellate, small punctures (Figure 10 (b)); punctures on sutural stria from contiguous to separated by 1 puncture diameter apart; other striae with punctures from 1–4 puncture diameters apart. Legs: Inner protarsal claw with a small, ventromedial, triangular to lobed process. Mesofemur nearly completely setose ventrally. Metafemur with minute punctures on ventral surface. Meso- and metatibia with medial carina strongly produced. Abdomen: Tergite 7 with stridulatory apparatus formed by 1 band of finely marked striae. Tergite 8 entirely covered with strong rugosity, setae scarce. Sternites 4–7 strongly rugopunctate on sides, with small punctures transversely scattered at middle of disc; sternites 5–7 with a row of setigerous punctures arranged on sides, disc glabrous; sternite 8 rugopunctate on sides, glabrous. Aedeagus: Parameres, in dorsal view, with basal half rounded laterally, outer margins becoming subparallel towards apical half; apical lobes broad (Figure 13 (k)). Parameres, in lateral view, with acute apex, bearing a transversal carina between dorsal and ventral surfaces; basal area bearing a weak carina (Figure 14 (k)).

Female description (Figure 16 (a))

Length: 33.0 mm. Width: 18.4 mm. Similar to male, except for: Prothorax: Pronotal cavity posteriorly limited by a transverse tubercle. Scutellar plate with scarce, setigerous punctures. Legs: Inner protarsal claw simple, without ventromedial lobe. Abdomen: Sternite 8 densely rugopunctate, with short setae confined on sides.

Distribution

Known only from Bolivia (La Paz and Santa Cruz) (Figure 23). Bothynus nyx is related to sub-Andean areas from Bolivia, with disjunctive distribution from B. laevipennis .