Phileurus bucculentus Ohaus, 1911

Grossi, Paschoal Coelho & Saltin, Jochen-P., 2014, Description of the female of Phileurus bucculentus Ohaus, with new country records and remarks for Phileurus carinatus Prell (Coleoptera, Scarabaeoidea, Dynastinae), Insecta Mundi 2014 (348), pp. 1-16 : 2

Phileurus bucculentus Ohaus, 1911

( Figures 1–2 )

Phileurus bucculentus Ohaus, 1911: 171

Female description. Length: 32 mm, width: 16 mm ( Fig. 2A–H ). Color dark brown, pronotum darker. Head: Surface wrinkled, except horns; hollow of vertex deep and wide, almost as wide as interocular width. Lateral horns subconical and moderately developed; clypeus triangular, laterally slightly impressed, apex acute, sharply reflexed. Frontal carina weakly marked between frons and vertex. Interocular width equals 5.5 transverse eye diameters; antennae 10 segmented, club as long as segments 2–7. Mandibles slender and narrow, arcuate on external edge, apex slightly bifurcated on internal view, acute; in ventral view just before apex with a small incision and tooth just before apex. Pronotum: Form narrower than elytra width; median, longitudinal furrow narrow, extending from near base to past middle joining to a deep and somewhat wide fovea. Furrow with fine, C-shaped punctures from base to apex, punctures becoming coalescent and then wrinkled in fovea and laterally. Sides punctate posteriorly; punctures decreasing in size and density from apex to base. Strong tubercle projecting forward just above anterior margin. Surface on anterior angles wrinkled, all margins complete. Elytra: Surface finely punctate with 11–12 rows of moderately sized, ocellate-umbilicate punctures, not equidistant from one another. Rows separated from each other by 3–4 puncture diameters. Intervals almost impunctate, surface flat. Pygidium: Surface finely punctate, punctures becoming denser near anterior margin; punctures fine; surface weakly convex on disc and slightly concave laterally. Legs: Protibiae tridentate, teeth acute, basal tooth wider, smaller, and laterally directed. Meso- and metatibiae with distal tooth obliquely truncate. Venter: Prosternal process large, subtriangle with a rounded apex, and with a transverse carina just before middle. Metasternum covered with long, dense setae.

Males ( Fig. 1A–I ). The males differ from females especially in the stronger development of the frontal horns that are at least twice the size of those of the female. Also, the pronotal fovea and tubercle are deeper and larger. The pygidium is distinctly more convex, and the sixth sternite narrower and sinuate distally ( Fig. 1E ), whereas the sixth sternite is subtriangular in females ( Fig. 2E ).

Remarks. Phileurus bucculentus seems to be an uncommon species, since it is not frequently encountered in collections, and until now is known only from Argentina. This species could be confused with P. carinatus Prell , but the pronotal tubercle is clearly more developed in both sexes of P. bucculentus , whereas this does not happen in P. carinatus , where the tubercle is usually more developed in males. Also, the pronotal furrow is clearly deeper anteriorly, just behind the tubercle, and the male genitalia have differences in the shape of the parameres.

Material examined. Three males and two females were studied from Argentina (Chaco, Charata and Castelli), and collected in January 2008 by local collectors ( EPGC and JPSC). No other data were provided.

Figures

Figure 1. Phileurus bucculentus Ohaus, male. A) Dorsal view. B) Lateral view. C) Ventral view. D) Head and pronotum, detail. E) Abdominal sternum, detail. F) Parameres in lateral and caudal views. G) Scutellum. H) Elytral disc, detail. I) Head and pronotum, in perspective view.

Figure 2. Phileurus bucculentus Ohaus, female. A) Dorsal view. B) Lateral view. C) Ventral view. D) Head and pronotum, detail. E) Abdominal sternum, detail. F) Scutellum. G) Elytral disc, detail. H) Head and pronotum, in perspective view.