Dichotomius (Cephagonus) vargasae, Nunes & Vaz-de-Mello, 2019

Nunes, Rafael V. & Vaz-de-Mello, Fernando Z., 2019, Taxonomic revision of Dichotomius (Cephagonus) Luederwaldt 1929 and the taxonomic status of remaining Dichotomius Hope 1838 subgenera (Coleoptera: Scarabaeidae: Scarabaeinae: Dichotomiini), Journal of Natural History 53 (37), pp. 2231-2351 : 2336-2337

6.2.: Dichotomius (Cephagonus) vargasae new species

( Figure 47 (e-h))

Diagnosis. this species is separated from other Cephagonus by the following combined characters: anterior portion of larger male pronotum disc with four tubercles aligned transversely; clypeo-genal angle sub-straight on malesı obtuse on females; females pronotum simply convex and having chagrinated microsculpture on disc (as D. mundus ); elytra having chagrinated microsculpture on interstriae disc (viewed under 30x magnifi- cation) (as D. mundus ); males sixth ventrite with strong groove all over its extension (as D. ascanius ); females sixth ventrite produced in a central-rounded lobe bifurcated apically ( Figure 10 (b-c)).

● HOLOTYPE (male): BRASIL: Espírito Santo. Sooretama. Reserva Natural Vale ( Cinco Folhas ). 19³08 ʹ 56 ” Sı 40³04 ʹ 08 ” Wı 71 m. Fezes humanas. 3-ii-2015. T Vargas [at CEMT ]. ● PARATYPES: same data of Holotype [4 ƋƋı 4 ♀♀ at CEMT].

Description (Holotypeı male). BL: 16 mmı PW: 8 mm. Colour: blackı shiny. Head: frontoclypeal surface smoothı genae surface with fine puncturesı interocular space with coarse punctures. Clypeo-genal angulation sub straight. Cephalic horn produced in a low conical tubercle. Pronotum: pronotal disc chagrinated with very fine punctures (viewed under 20x magnification). Anterior portion of pronotal disc delimited by a pair of weak knobs. Posterior margin with a single row of ocellate puncture irregularly spaced. Metasternum: almost glabrousı margin of anterior lobe and sides with sparse long setae. Elytra: striae deeply impressed with well-defined punctures separated by their diameter. Interstriae convexı shiny and with chagrinated microsculpture. Abdomen: sixth ventrite with strong groove all over its extension. Punctures present continuously along anterior margin of each ventrite and denser at sides. Ventrites 3 – 5 with a single setae on each side. Aedeagus ( Figure 47 (e-h)): dorsallyı apexes roundedı convergentı excavation taking 3/4 of paramera lengthı basal excavations rounded. Laterallyı subtle declivity towards apex. Ventrallyı basal excavations rounded and wideı separated by a prolongation produced in a carina; subgenital plates emarginated both basally and apically.

Morphological variation. males BL: 14 – 16 mmı PW: 7 – 8 mm. Females BL: 13 – 14 mmı PW: 7 – 9 mm and are distinguished from males as follows: Head: frontalı clypeal and genal surfaces striatedı transverse wrinkled. Cephalic carina very lowı producing a very weak tubercle. Pronotum: lacking lobes and declivitiesı disc smoothı lacking microsculpture. Abdomen/Pygidium: sixth ventrite with a central-rounded lobe advancing beneath pygidium apex.

Distribution. municipality of Sooretamaı state of Espírito Santoı BRAZIL.

Systematic Remarks. males are similar to those of D. ascanius (pronotum and sixth ventrite groove on males) however females 6th ventrite is similar from D. punctulatipennis and a new species of the bicuspis group in the subgenus selenocopris.

Etymology. named after our friend Dr. Tércia Vargas dos Santos (Universidade Federal de Viçosaı Minas Gerais)ı who collected the holotype.

Figures

Figure 10. (a) Abdominal ventrites of a male of D. vargasae. (b) Detail of a sixth ventrite (white arrow) of a female of D. vargasae. (c) Sixth ventrite of female of D. vargasae. (d) Abdominal ventrites of a female of D. rondoniaensis. Pyg – pygidium.

Figure 47. D. rondoniaensis: (a) male dorsal habitus; (b) paramera dorsal view; (c) paramera ventral view; (d) paramera lateral view. D. vargasae: (e) male dorsal habitus; (f) paramera dorsal view; (g) paramera ventral view; (h) paramera lateral view.