Tomarus ebenus ( De Geer, 1774 )

López-García, Margarita M., Gasca-Álvarez, Héctor J. & Amat-García, Germán, 2015, The scarab beetle tribe Pentodontini (Coleoptera: Scarabaeidae: Dynastinae) of Colombia: taxonomy, natural history, and distribution, Zootaxa 4048 (4), pp. 451-492 : 481-482

Tomarus ebenus ( De Geer, 1774)

( Figs. 117 – 123 )

Scarabaeus ebenus De Geer, 1774: 317 .

Scarabaeus cordatus Fabricius, 1792: 31 . Cyclocephala scarabaeinus Perty, 1830: 46 .

Description. Habitus as in Fig. 117 . Length 24.0–25.0 mm (♂), 25.2–25.5 mm (♀). Width 13.0– 13.5 mm (♂), 13.5–14.0 mm (♀). Color black to dark brown. Head: Frons concave between eyes and before frontal tubercles; surface deeply punctate, nearly smooth on vertex and only with sparse, deep punctures. Frontoclypeal region with 2 transverse tubercles broadly separated from one another (about 5 tubercle diameters). Frontoclypeal suture present, as a weak carina on each side. Clypeus with surface transversely rugose; shape trapezoidal, apex broadly truncate; with 2 small teeth, teeth reflexed, widely separated (about 5 tooth diameters) ( Fig. 119 ). Interocular distance equals 3.5 times the transverse ocular diameter. Antennal club subequal in length to antennomeres 2–7. Mandibles with 2 apical and one lateral tooth. Pronotum: Surface with sparse, small, deep punctures, denser on lateral margins. Apical tubercle small, only as a small tumescence ( Fig. 118 ). Subapical fovea longitudinally oval, deep to shallow, rugose. Scutellum: Surface nearly smooth, only with some minute, sparse punctures. Elytra: Surface with deep, large, ocellate punctures, some smaller between intervals; 3 pairs of double rows of punctures slightly distinct; elytral suture present. Pygidium: Surface with deep evenly sparse punctures, becoming nearly smooth on basal third. Surface strongly (males) to weakly convex (females). Legs: Protibia tridentate, basal tooth distinctly removed from others. Male protarsus enlarged, outer claw incised. Apex of metatibia crenulate, with 7–8 spinules on the apical margin. Apex of first metatarsomere subtruncate. Venter: Prosternal process long, extending beyond procoxae; apex transversally oval, split, posterior part bordered by long yellow setae. Parameres: Basal third broad; lateral teeth small and with apex acute; apical third narrowed; apices strongly expanded outwards ( Figs. 120–121 ). Spiculum gastrale: Base larger than lateral branches, apex truncate ( Fig. 122 ).

Diagnosis. This species is remarkably similar to T. similis . They can only be separated by a pronotal fovea that is shallow and rounded in T. ebenus , but deeper and nearly triangular in T. similis . Additionally, the shape of the parameres is diagnostic for each species, being wider and shorter in T. ebenus and slender in T. similis .

Locality records. ( Fig. 123 ) 39 specimens, 17♂, 22♀. Specimens were seen from UPN, ICN, MPUJ, CEUN, LEUC. Casanare (1): Monterrey (1). Cundinamarca (3): Agua de Dios, Vda. Los Chorros, Granja de Ibañez (1). Anapoima (1). Vianí (1). Guainía (1): Inírida, Com. La Ceiba (1). Meta (3): Remolinos (3). Nariño (1): Pasto (1). Valle del Cauca (25): Buenaventura (25). Vichada (5): Gaviotas (5).

Temporal distribution: March (5), April (2), September (1), October (6), November (25).

Distribution. Mexico, Guatemala, Belize, Honduras, Nicaragua, Colombia, Venezuela, Brazil, Peru, Bolivia ( Endrödi 1969; Ratcliffe & Cave 2006; Ratcliffe et al. 2013), and Lesser Antilles ( Peck et al. 2014). In Colombia, it was found in seven departments, but it has been reported also in Antioquia ( Restrepo-Giraldo et al. 2003) and Chocó ( Neita et al. 2006).

Natural history. The species was collected in forests, grasslands and crops of Colocasia sculenta (Linnaeus) (Araceae) known as “Papachina”. Piedrahíta et al. (2007) reported the species affecting the roots of this plant on the coasts of Chocó and Valle del Cauca. Peck et al. (2014) indicated that adults are attracted to lights, and the larvae feed on small tubers of Dioscoreaceae and Convolvulaceae and may also damage gardens. Examined specimens were taken at 100 – 2,100 m, being most abundant in lowlands.

Figures

FIGURES 117 – 123. Tomarus ebenus. 117) habitus in dorsal view, 118) habitus in frontal view, 119) head and pronotum in dorsal view, 120) parameres in frontal view, 121) parameres in lateral view, 122) spiculum gastrale, 123) locality records in Colombia.