Dichotomius (Cephagonus) blancoi, 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 : 2315-2316

3.10.: Dichotomius (Cephagonus) blancoi new species

( Figure 35 (a-e))

Diagnosis. this species is separated from other in the group by the following combined characters: males pronotum with pair of weak knobs on the anterior portion of disc; elytral striae and punctures deeply impressed; males paramera with a longitudinal carina inserted on the longitudinal excavation ( Figure 35 (e)). Very similar to many species of the quadraticeps groupı being differentiated basically by males genitalia.

● HOLOTYPE (male): VENEZUELA. Tachira. Parque Paramillo. Edo. Tachira V32. Mayo 1993. Leg. J. Blanco [at CEMT ].

● PARATYPES: same data of holotype [1 ♀ at CEMT]; BRAZIL. Roraima. 1997. [1 Ƌı 1 ♀ at CEMT].

Description (Holotypeı male). BL: 15 mmı PW 9 mm. Colour: dark brown and blackı shiny. Head: dorsal surface smooth except for few striations near clypeo-genal groove. Gena borders slightly curved inward. Clypeo-genal junction slightly curved upward. Cephalic carina longer than wideı conical with rounded at apex. Pronotum: borders smoothı not serrated. Pronotal disc shinyı lacking punctures and having two weak central lobes on the anterior portion of disc. Ocellate punctures present along pronotal margins except at anterior portion adjacent to eyes. Metasternum: sides and margins of anterior lobe covered by hair. Anterior portion of anterior lobe glabrous with chagrinated microsculpture. Setigerous punctures evenly spaced at sides. Elytra: striae deeply impressed having fine punctures spaced 2-four times their diameter. Interstriae convex. Interstriae disc with dark brown colourı lacking microsculpture with very fine punctures (20 x). Abdomen: sides of each ventrite excavated with groups of ocellate punctures and 1 – 4 setae. Puncture of each ventrite interrupted medially as well as groove along the posterior margin of sixth ventrite. Aedeagus ( Figure 35 (b-e)): dorsallyı paramere apexes roundedı convergent. Longitudinal excavation taking the whole paramera length and with midlongitudinal carina interrupted medially; longitudinal carina with acute apex; basal trapezoidal excavation present. Laterallyı subtle declivity from basis towards apex; widely excavated (mid-longitudinal carina also seen in this view). Ventrallyı basis with two wide elliptical excavations. Subgenital plate widely emarginated at apex and rounded basally.

Morphological variation. females BL: 12 – 15 mmı PW: 7 to 9 mm and distinguished from males as follows: Head: fronto-clypeal surface striated. Cephalic carina produced in a weak pair of central tubercles. Pronotum: simply convex. Elytra: striae weakly impressed deeply impressedı punctures not distinguishable. Interstriae disc flatı with chagrinated microsculpture. Blue sheen present near basis. Abdomen: sixth ventrite bearing a weak emargination at central portion.

Distribution. Venezuela and Brazil (RO)ı this region is also known as Tepuís.

Etymology. named after Jorge Blanco (Universidad Nacional Experimental del Táchiraı Venezuela)ı who collected the holotype.

Figures

Figure 35. D. blancoi: (a) male dorsal habitus; (b) paramera dorsal view; (c) paramera ventral view; (d) paramera lateral view; (e) detail of the carena found on the middle of paramera longitudinal excavation. D. candangoi: (f) male dorsal habitus; (g) paramera dorsal view; (h) paramera ventral view; (i) paramera lateral view.