Dichotomius (Cephagonus) frizzasae, 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 : 2319-2320

3.14.: Dichotomius (Cephagonus) frizzasae new species

( Figure 37 (e-h))

Diagnosis. separated from other in the quadraticeps group by the following combined characters: clypeo-genal angulation in larger males acute and forming a teeth (like D. edmondsi , D. paschoali , D. reichei ); males pronotal disc with a central pair of lobes on anterior portion (idem); males cephalic horn or tubercle rounded apically and paramera in dorsal and ventral view strongly narrowed medially (as D. paschoali and D. emas ). Externallyı this species is very similar to D. fissiceps , D. reichei , D. barbarae , D. furtadoi and D. paschoali and is differentiated by type-locality and paramera characters (key and diagnosis).

● HOLOTYPE (male): BRASIL: Distrito Federal. Brasília. Planaltina. ESEC Águas Emendadas . 15³32 ʹ 31 ” Sı 47³36 ʹ 49 ” W. Pitfall . 16-31-xi-2009. MR Frizzas [at CEMT].

● PARATYPES: same data of Holotype [46 ƋƋı 20 ♀♀ at CEMT].

Description (Holotypeı male). BL: 20 mmı PW: 13 mm. Colour: blackı shiny. Head: frontoclypealı genal and inter-ocular surfaces smooth. Gena borders slightly curved inward. Clypeo-genal angle acute. Cephalic carina longer than wideı similar height to pronotumı conical with rounded apex. Pronotum: pronotal disc shinyı lacking punctures and having a central pair of lobes. Region adjacent to eyes with a row of ocellate punctures. Posterior margin having 1 – 2 rows of ocellate punctures. Metasternum: sides and margins of anterior lobe covered by long hair. Anterior portion of anterior lobe glabrous. Setigerous punctures equally spaced at sides. Elytra: striae deeply impressed having fine punctures spaced by twice their diameter. Interstriae slightly convexı disc with black colourı lacking microsculptureı with very fine punctures (20 x). Abdomen: sides of each ventrite excavated near anterior portionı with groups of ocellate punctures- some punctures setigerous with very short hair (under 35x magnification). Ventrite 1 with 8 – 10 setae at each side. Puncture of each ventrite interrupted medially as well as groove along the posterior margin of sixth ventrite. Aedeagus ( Figure 37 (f-h)): dorsallyı paramere strongly narrowed medially. Apexes roundedı parallel; longitudinal excavation absentı produced in a pair of knobs. Laterallyı abrupt declivity from basis towards apex; longitudinal sinuous carina separating ventral of dorsal excavations. Ventrallyı basis with three tuberclesı one central and two lateral ones. Subgenital plate rounded apically and emarginated basally.

Morphological variation. males BL: 12 – 20 mmı PW: 7 – 13 mm. Male genitalia comparison allows us to identify three phenotypes. Larger males (described above) bear pronotal lobes and tall cephalic horns. Smaller males have simply convex pronotum with deeply impressed fine puncture on disc (10x)ı and the cephalic horn is produced in a conical simple tubercle. Females BL: 16 – 19 mmı PW: 8 – 12 mmı distinguished from males as follows: Head: fronto-clypeal surface striated. Coarse puncture present posterior to cephalic carina. Cephalic carina transversalı bifurcated at apex forming a weak pair of tubercles. Pronotum: simply convexı lacking lobesı borders produced into carinas. Elytra: striae deeply impressedı punctures separated by twice their diameter. Blue sheen present near basis. Abdomen: sixth ventrite bearing a pair of weak tubercles on central portion.

Distribution. municipality of Brasíliaı administrative region of Planaltinaı Brazil ( Figure 36 ).

Etymology. named after our friendı the entomologist Marina Regina Frizzas (Universidade de Brasíliaı Brasil)ı who collected the holotype.

Figures

Figure 36. Distribution map of D. ricardosilvaiı D. marcoscarvalhoiı D. furtadoiı D. barbaraeı D. tissianiaeı D. eması D. frizzasae and D. candangoi.

Figure 37. D. edmondsi: (a) male dorsal habitus; (b) paramera dorsal view; (c) paramera ventral view; (d) paramera lateral view. D. frizzasae: (e) male dorsal habitus; (f) paramera dorsal view; (g) paramera ventral view; (h) paramera lateral view. D. gardneri (i) male dorsal habitus; (j) paramera dorsal view; (k) paramera ventral view; (l) paramera lateral view.