Dichotomius (Cephagonus) emas, 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 : 2323-2324

3.17.: Dichotomius (Cephagonus) emas new species

( Figure 39 (a-d))

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 knob 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. frizzasae ).

● HOLOTYPE (male): BRASIL: Goiás. Mineiros. PARNA Emas . 17³53 ’ Sı 53³59 ʹ Wı 820 m. MF Souza [at CEMT].

● PARATYPES: same data of holotype [1 Ƌı 2 ♀♀ at CEMT].

Description. colour: blackı shiny. Head: fronto-clypealı genal and inter-ocular surfaces smooth. clypeo-genal angle straight. Cephalic carina longer than wideı conical with rounded apex. Pronotum: disc shinyı lacking punctures and having a central anterior knob with a weakly emargination at each side of the knob. Posterior margin with a row of ocellate punctures interrupted medially. Metasternum: sides and margins of anterior lobe covered by long hair. Anterior portion of anterior lobe glabrous but bearing ocellate punctures. Setigerous punctures equally spaced at sides. Elytra: striae deeply impressed having coarse punctures spaced by their diameter. Interstriae convexı disc lacking microsculpture with very fine punctures (20 x). Abdomen: ventrite 1 with groups of 5 – 8 setae at each side. Puncture of each ventrite interrupted medially as well as groove along the posterior margin of sixth ventrite. Aedeagus ( Figure 39 (b-d)): dorsallyı paramere narrowed medially – emargination truncated ‘ V ’ shaped. Apexes roundedı parallel; sub-apical spine present; longitudinal excavation taking half of paramera length. Basal excavation narrowı delimited by basal knobs. Laterallyı abrupt declivity from basis towards apex. Ventrallyı basis with a single central tubercle and two lateral-rounded excavations; subgenital plate emarginated basallyı rounded apically.

Morphological variation. male BL: 16 mmı PW: 9 mm. Female BL: 16 mmı PW: 9 mm and 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 carinate. Elytra: striae weakly impressedı punctures separated by their diameter. Blue sheen present near basis. Abdomen: sixth ventrite bearing a pair of weak tubercles at central portion.

Distribution. Brazilı state of Goiás in the municipality of Mineiros (Emas National Park) ( Figure 36 ).

Etymology. eması noun in appositionı refers to Emas National Park (Mineirosı Goiásı Brazil)ı type locality and where a considerable portion of Cerrado is preserved. This new species is one of the many endemic species of Taquari Plateauı in central Brazil.

Figures

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

Figure 39. D. emas: (a) male dorsal habitus; (b) paramera dorsal view (black arrow indicating strong medial constriction on paramera side); (c) paramera ventral view (black arrow indicating strong medial constriction on paramera side); (d) paramera lateral view. D. marcoscarvalhoi: (e) male dorsal habitus; (f) paramera dorsal view; (g) paramera ventral view; (h) paramera lateral view. D. paschoali (i) male dorsal habitus; (j) paramera dorsal view; (k) paramera ventral view; (l) paramera lateral view (black arrow indicating basal excavation).