Triodontus viettei Frolov, Montreuil & Akhmetova

Frolov, Andrey V., Montreuil, Olivier & Akhmetova, Lilia A., 2016, Review of the Madagascan Orphninae (Coleoptera: Scarabaeidae) with a revision of the genus Triodontus Westwood, Zootaxa 4207 (1), pp. 1-93 : 76-78

Triodontus viettei Frolov, Montreuil & Akhmetova , new species

( Figs. 39 A–H)

Type material. Holotype ( Figs. 39 A–C, E–G), male, “ Madagascar Antsianaka et lac Alaotra 2e Trimestre 1889 Perrot Freres / HOLOTYPUS Triodontus viettei Frolov et al. 2010 ” ( MNHN) .

Paratypes: one male, “Tananarive Lamberton” (MNHN); one male and two females, “ Madagascar Nord, contreforts du Tsaratanana, Haut Sambirano, 1200 m, vallee de la Besanetribe [ Upper Sambirano River , 1200 m a.s.l., Besanetribe Valley], 5/ 9-XII-1963, P. Viette ” ( MNHN) ; two males, “MADAGASCAR Reg. Perinet [Andasibe] G. Olsoufieff col. 193” (MNHN).

Diagnosis. Triodontus viettei is most similar to T. hildebrandtii but differs from it in having outer lobes of the parameres with slit-shaped, lateral notches, as opposed to having wide lateral notches in T. hildebrandtii .

Description. Holotype, male. Body length 14.5 mm. Color uniformly dark brown, legs, antennae, and underside of the body slightly paler ( Fig. 39 A–B).

Frontoclypeus slightly convex anteriorly, rounded laterally, anterior margin crenulate and setose in dorsal view. Eyes relatively small (diameter slightly smaller than the distance between eye and gula in ventral view), incompletely divided by canthus into small dorsal and large ventral parts. Frontoclypeus with tubercles mediad of each eye and with long horn in the center of frontoclypeus. The horn is longer than width of the head, acutely rounded apically, somewhat curved caudally, slightly rugose on posterior side.

Pronotum with a bulge medially, with large excavations at each side of bulge, and with 2 ridge-shaped tubercles laterally of each excavation. The median bulge is rounded and somewhat depressed on the top, with 2 distinct tubercles and a depression, receiving frontoclypeal horn. Lateral margins with wide border appearing somewhat crenulate (in dorsal view), with a row of brown setae. Anterior margin with wide, smooth border. Posterior margin with fine border; not crenulate; punctate with small, narrow, longitudinal punctures. Surface of most pronotum almost smooth, with minute, feebly visible punctation.

Scutellum rounded apically, visible part is about 1/13 length of elytra.

Elytra convex, with distinct humeral humps. Maximum width approximately at basal 1/3. Elytra with 10 feebly visible striae on disc and with oblique line from base of 6th stria to approximately middle of 8th stria. Stria with small punctures. Intervals with sparse, minute punctures, almost smooth. Base of elytra with an irregular row of coarse punctures each bearing a small, yellow seta.

Sternite 8 medially as wide as sternites 2–5 combined, without tubercle or concavity in the middle, with apical border deeply sinuate medially ( Fig. 39 G).

Parameres with outer lobes being relatively wide (in dorsal view) and having slit-shaped, lateral notches ( Fig. 39 E). Internal sac of the aedeagus with 1 strongly sclerotized sclerite and 2 additional similar sclerites ( Fig. 39 F).

Female. Females differ from males in having apical spur on protibiae; absence of the head and pronotum armature; densely punctate dorsal side of the head; and in longer abdominal sternites including 6th sternite, which is evenly rounded apically ( Fig. 39 D).

Variation. Body length of the examined paratypes varied from 13.5–14.0 mm (males) and from 11.7–11.9 mm (females).

Distribution. Triodontus viettei is known from four localities in eastern and northern Madagascar ( Fig. 39 H).

Etymology. The new species is dedicated to the memory of Pierre Viette, French entomologist, specialist of Noctuidae (Lepidoptera) of Madagascar.

Figures

FIGURE 39. Triodontus viettei, holotype male (A, B, C, E, F, G), paratype female (D). Habitus in dorsal (A, D) and dorsolateral view (B), labels of holotype (C), aedeagus in lateral view and parameres in dorsal and ventral view (E), internal sac of aedeagus (F), abdomen (G), distributional records (H).