Phileurus nasicornis Burmeister, 1847 (original combination) (Fig. 3).

Species of Oryctophileurus are distinguished from other Phileurini by a combination of the following apomorphic characters: a single cephalic horn with lateral carina, pronotal cavity with ocellate punctures and two teeth or tubercles close to the anterior pronotal margin, teeth vertically positioned at about the same level as the outer eye margins.

The following characters were cited by Endrödi (1985) for Oryctophileurus, Amblyodus, Microphileurus Kolbe, Metaphileurus Kolbe, Trioplus Burmeister, and Goniophileurus Kolbe and are here not considered as generic: outer side of mandible tridentate; antenna 10-jointed; elytra with punctate rows; proleg sexually monomorphic, protarsus not thickened in male. Oryctophileurus and Amblyodus are distinguished from the other mentioned genera by large horns, a distinctly developed and posteriorly carinate pronotal cavity and four external teeth on the protibia (Endrödi 1985; Ide 1998). However, in Amblyodus the two cephalic horns lack the lateral carina, the punctures in the pronotal cavity are predominately fused to short, transverse ridges, and the teeth close to the anterior pronotal margin are absent. Except for the horn number, these generic differences between Oryctophileurus and Amblyodus have not been recognized by previous workers.

Based on the combination of apomorphic characters of Oryctophileurus that lacks in Amblyodus we suggest retaining the genus Oryctophileurus.

Colombia: Cauca dep., Cauca Valley: 1 male with body length 19 mm, det. Endrödi 1976 (ZMHB); Boyacá dep., Muzo muni.: 1 female with body length 20 mm, S. Apollin coll., det. Ohaus, revised by Endrödi (1977) (ZMHB).

Color dark brown, moderately shining. Horn on frons not projecting above anterior edges of pronotal protuberance, weakly recurved, in female with truncate apex; ocular canthus rounded in male, and subquadrate in female. Pronotum broadly rounded, more in female. Distance between inner teeth of dorsal pronotal protuberance narrower than distance between eyes. Pronotal protuberance on same level with elytra. Development of horn and pronotal protuberance equal in both sexes. Elytra striate, with five well defined discal striae; striae regular, at sides weakly defined; punctures regular, about the same size of those at disc. Meso and metatibiae with 4 to 5 distal teeth. Pygidium regularly convex in both sexes, more in female, and densely and finely wrinkled. Parameres with basal half broad, apex slender, straight.

The species is known only from the Cauca Valley in Colombia, which is surrounded by the parallel, peninsula-like projections of the Andean Cordillera Occidental and Cordillera Central and the Muzo municipality which is situated on the eastern slope of the Cordillera Oriental (Fig. 1A). These areas include wet premontane forest and, to a lesser extent, upper montane forests and paramos (Espinal 1992).

Peru: holotype, female, body length 20.4 mm, unknown locality (ZMHB).

Peru: Junin dep.: Satipo prov., Chanchamayo Valley: 1 male with body length 20 mm (EPGC); Satipo prov., Rio Tambo valley, Paraíso Tuncama, ~1300 m a.s.l.: 1 female with body length 19.4 mm, (EPGC); Rios Pichis & Perene, 600–900 m a.s.l., Soc. Geog. De Lima col., 1 male (MZSP).

Color black, moderately shining to shining. Enlarged elytral punctures. Punctures and elytral striae arranged in irregular lines (Figs 4A, C). Horn widely projected above body in male. Pronotal protuberance comparably flat and developed as in female.

Male. (Figs 4A, B). Body elongate, cylindrical. Surface entirely black, glabrous, moderately shiny to shiny; dorsally almost totally punctate; punctures ocellate, moderate to very large. Legs, sterna, second abdominal ventrite, and basal margin of pygidium setose.

Head. Surface laterally wrinkled, in frontal view rugose. Clypeus subtriangular, apex rounded and emarginated, weakly reflexed; clypeal carina absent; sides concave. Canthus widely rounded and extending into middle of eye. Frons with long, recurved, cylindrical horn with narrow apex; each side of horn with elongated, weak carina, anterior surface with slightly concave furrow, furrow reaching apex. Mandible tridentate, teeth upturned. Mentum with longitudinal furrow wider anteriorly and posterior concavity narrow with subparallel sides.

Pronotum. Shape subquadrate, narrower than elytra together. Discal area covered by ocellate punctures combined with C-shaped, coalescent punctures; discal surface flat and declivous anteriorly (Fig. 4A, B); anterior and lateral margins complete with a marginal bead, concave at middle; posterior marginal bead absent. Pronotal disc carinate, carina convex, smooth; anterior carina more pronounced; near anterior border with a conspicuous tubercle present in each anterolateral corner; posterior carina joined posteriorly on pronotal margin, bisinuous. Anterior angle acute, posterior rounded. Middle apex laterally with smooth convex carina, intercalated by rugose area and coarse punctures. Prosternal process long, trapezoidal, concave at base and posteriorly produced; base with a spine like posterior process.

Elytra. Striae irregular, and not defined, even laterally; punctures ocellate, irregular, larger on discal area and becoming smaller laterally and posteriorly; elytral apices densely punctate, punctures small to moderate; apical umbone convex, smooth. Scutellum triangular, densely punctate; punctures ocellate, moderate in size. Pygidium. In lateral view widely convex; surface totally punctate; punctures smaller and denser near anterior margin and sides, sparser and larger to apex; apex with marginal bead.

Legs. Protibia with 4 external teeth; basal tooth smaller. Apex of mesotibia with 4 teeth. Apex of metatibia with 5 teeth.

Aedeagus. Shape symmetrical (Fig. 5D), narrowing abruptly at middle; apex inflated, rectangle shaped, truncate; sides subparallel. In lateral view surface concave and with, acute, small projection near lateral base (Fig. 5C).

Oryctophileurus varicosus was described by Prell (1934) from an unknown locality in Peru. Records from Rio Pichis (600–900 m a.s.l.), Chanchamayo Valley (Junin dep., Satipo prov.) and Paraíso Tuncama (same province) at ~1300 m a.s.l. (Fig. 1A) suggest that this species occurs in the Peruvian Yungas and adjacent subandine transitional forest. The forest in this area is classified as evergreen premontane, subhumid to humid, South Yungas forest (Josse et al. 2003).

The records cited here are the only known specimens. Endrödi (1977) described the holotype as a male possibly based upon the fact that it has a horn. Endrödi (1985) correctly redescribed the type specimen as a female, indicating that the male was unknown as was pointed out in the original description by Prell (1934). Ide (1998) cited a male specimen from Rios Pichis & Perene, Peru, which was, however, not described. We describe here the male of Oryctophileurus varicosus for the first time.

Peru: holotype, male, body length 18.5 mm (ZMHB).

Bolivia: La Paz dep., Nor Yungas prov., Caranavi, I-2003, 2 males with body length 18 mm and 20 mm and 1 female with body length 18 mm (EPGC); Route Coroico-Caranavi, XII-2008, 1 male (EPGC); La Paz dep., Calisaia, V-1925, G.L. Harrington col., 1 male (MZSP); Beni dep., Cosincho, VIII-1925, G.L. Harrington col., 1 female (MZSP).

Color black, strongly shining. Head anteriorly flat, not concave; canthus subquadrate, in some specimens weakly projected forward; horn in males strongly recurved, on about the same level or slightly higher than posterior pronotal protuberance. Mentum with longitudinal furrow flat and wide, as well as posterior margin. Distance between inner teeth of dorsal pronotal protuberance in male wider that width between eyes (Fig. 6A); in females separated by a concavity with occelate punctures; pronotal concavity accounts for about 40–50 % of dorsal pronotal surface in males. Ocellate punctures above posterior-lateral pronotal margin continuous (Fig. 7C). Each elytron with 10 striae; punctures ocellate, sometimes coalescent and elongated, decreasing in size to sides; interstriae smooth, convex. Striae and interstitial punctures arranged in regular lines Mesotibia with 3 to 5 apical teeth; metatibia with 4 to 6 apical teeth. Pygidium in males distinctly more convex than in females, moderately punctate, denser at base and sides. Aedeagus symmetric (Fig. 5A); parameres with apex rounded to subtriangle shaped (Fig. 5B).

Oryctophileurus armicollis is known from Peru (Prell 1911; location not specified) and the Andean (Nor Yungas, La Paz dep.) and Subandean (Cosincho, Beni dep.) areas of Bolivia (Fig. 1A). The ecosystem between 800 and 2000 m a.s.l. in this area is considered as South Yungas submontane, subhumid forest (Josse et al. 2003) and receives an annual precipitation between 1500–6000 mm (Ibisch et al. 2003a). The locality data suggests that this species is closely associated with the Bolivian Yungas forest and might also occur in the Peruvian Yungas forest.

Holotype: male, “Bolivia / Tarija / O’Connor province / Tariquía National Reserve / S21°59'01, W64°12'30 / 1008 m a.s.l. / Tucuman-Bolivian subhumid forest / gully close to small mountain river / 25-XI-2011 / R. Perger leg.” Allotype: female, same location data as the holotype, 20-XI-2011, F. Guerra leg.

Oryctophileurus guerrai sp. n. is distinguished from the morphologically similar Oryctophileurus armicollis by the distance between the inner teeth on the dorsal pronotal protuberance (in males as wide as width between eyes) (Figs 7B, 8A) and in females by the inner teeth separated by only a small fissure (Fig. 8C). In smaller males (body length 18.5 mm) of Oryctophileurus armicollis the distance between the inner teeth of the pronotal protuberance is wider than the width between the eyes and in larger males (body length 20 mm) as wide as the distance between the outer eye margins (Fig. 6A). In females of Oryctophileurus armicollis the inner teeth of the pronotal protuberance are separated by a comparably wide, continuous, parallel concavity containing ocellate punctures (Fig. 6C).

In both sexes of Oryctophileurus guerrai the ocellate punctures above the posteriolateral pronotal margin are smaller, shallower and sparser than in Oryctophileurus armicollis and the area of ocellate punctures above posteriolateral pronotal margin is reduced laterally (Figs 7D; 8B, D). In both sexes of other Oryctophileurus speciesthe pronotum posteriolaterally has a continuous area of distinctly developed, ocellate punctures.

In the male Oryctophileurus guerrai the pronotal protuberance is dorsally higher and the cephalic horn longer (Fig. 8B) than in similar-sized Oryctophileurus armicollis (Fig. 6B) and Oryctophileurus nasicornis (Fig. 3B). In Oryctophileurus nasicornis, both characters are less produced. In the male of Oryctophileurus varicosus (Fig. 4B), with its slightly larger body, the pronotum is much flatter than in the male of Oryctophileurus guerrai.

Holotype male (Figs 8A, B). Body length 20 mm, width 9 mm. Body elongate, cylindrical, head and pronotum brownish black dorsally, elytra black, body ventrally dark brown, dorsal surface glabrous. Legs, sterna, second abdominal ventrite and basal margin of pygidium setose.

Head. Surface smooth, finely punctate. Clypeus subtriangular, laterally emarginated, slightly upturned, and with acute apex. Cephalic horn recurving over pronotum, attenuate, apex narrowly rounded; surface at base coarsely punctate, with a lateral carina. Mandible tridentate with inner tooth more acute; teeth upturned. Antenna 10 segmented; club with antennomeres subequal in length.

Pronotum (Figs 7B, D; 8A, B). Shape subtrapezoidal, evenly rounded laterally, smooth, with 2 impressions posteriolaterally; posterior edges slightly obtuse. Basal half smooth, longitudinally ridged, dorsally bulging until transverse median carina, with 2 dorsolateral, coarsely punctate concavities on both sides; transverse median carina with 4 obtuse teeth, 2 inner teeth dorsally with small concavity, distance between inner teeth of dorsal pronotal protuberance as wide as width between eyes; anterior half of pronotum strongly concave, with ocellate punctures, 2 obtuse teeth close to anterior pronotal border, teeth at same level with lateral eye margins when seen from dorsal and lateral views. Prosternal process trapezoidal, concave at the base, posteriorly produced; base with spine-like process posteriorly.

Elytra. Surface smooth, with continuous, slightly convex carinae, weakly impressed interstriae, and with ocellate punctures. Pygidium. Shape convex in lateral view; surface densely punctate; punctures ocellate, moderately sized, elongate near basal margin.

Legs. Protibia with 4 teeth, basal tooth weakly developed. Meta- and mesotibia apically with 3 broaden, shovel-shaped teeth, each tooth additionally furnished with small, apical teeth. The specimen was found dead with damaged abdomen, soft parts and genitalia missing.

Female allotype (Figs 8C, D). Similar to male except by the following features: body length 19 mm, width 8.2 mm; head with cephalic horn less developed, reaching only dorsal pronotal protuberances when seen in lateral view; pronotum longer than high, dorsal longitudinal pronotal concavity about as narrow as width of cephalic horn, uppermost teeth of dorsal pronotal protuberances obtuse, separated by a small fissure.

The species is named after our friend and colleague, Fernando “Fideo” Guerra, for his lifetime commitment to the investigation of the Bolivian fauna. His participation in the actual survey in the southern Bolivian Andes has led to the discovery and description of several previously unknown taxa (e.g., Perger and Guerra 2012), and he was also the first to collect an individual of Oryctophileurus guerrai sp. n.

Oryctophileurus guerrai is known only from the northwestern area of Tariquía National Reserve (Tarija department) in the southern Bolivian Andes (Fig. 1). The forest in the this area is considered subandine subhumid, semi-deciduous, Tucuman-Bolivian forest (TBF) (Navarro and Ferreira 2011) with a mean annual temperature of 18.7 °C and an annual rainfall of 1334 mm (SENAMHI 2007). Oryctophileurus guerrai is likely endemic to TBF (see discussion below) and might also occur in the northern limit (Santa Cruz department) and the Argentinean portion of this forest type (Jujuy, Salta and Tucuman departments).

The two individuals of the new species were collected in a narrow valley (elevation 1008 m a.s.l.) (Fig. 1C). The female was observed during the day on the floor of the densely vegetated, moist gully (Figs 1C, D). The male was found dead in a similar habitat. No individuals of the species were observed in subhumid forest along the slopes and during eight nights of sampling with a light trap close to the collection area. Like the other species of this genus, which are only known from few individuals, Oryctophileurus guerrai might be rare or has a cryptic way of life.

As in males of other dynastine taxa with exaggerated secondary sexual traits(e.g., Eberhard 1979; Rowland 2003), the cephalic horn and pronotal structures of Oryctophileurus armicollis males (and likely in the males of other Oryctophileurus species) vary allometrically. Larger males have larger horns and pronotal armature with respect to their body length. Accordingly, such characters should be compared in specimens having a similar size. Nevertheless, the distance between the inner pronotal protuberance teeth appears to be positively allometric in Oryctophileurus armicollis, since it is wider in larger males (body length 20 mm) than in smaller males (body length 18.5 mm). In the male (body length 20 mm) of Oryctophileurus guerrai the inner pronotal protuberance teeth are separated by a gap (Fig. 6B) that is narrower than in the smaller male of Oryctophileurus armicollis (body length 18.5 mm), indicating that the ratio of body length/ pronotal protuberance teeth distance is never overlapping inter-specifically between similar-sized individuals.