Dichotomius (Cephagonus) barbarae, 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 : 2314-2315

3.9.: Dichotomius (Cephagonus) barbarae new species

( Figure 33 (i-l))

Diagnosis. this species is separated from other in the group by the following combined characters: larger males pronotum with a single central lobe on anterior portion of disc; elytral striae and puncture deeply impressed; males paramera with sub-apical spine (as D. fissiceps ) and paramera not narrowed posterior do sub-apical spine on dorsal view. Externallyı this species is very similar to D. reichei and D. fissiceps andı like bothı external characters are subject to strong variation.

● HOLOTYPE (male): BRASIL: Mato Grosso. Chapada dos Guimarães. Vale do Jamacá. 15³27 ʹ 51 ʹ ’ Sı 55³42 ʹ 45 ʹ ’ Wı 760 m. Gallery forest. FIT. 15-iii-2015. RV Nunes [at CEMT ].

● PARATYPES: same data of Holotype [1 Ƌı 1 ♀ at CEMT]; same data of Holotype but 9-ii-2013. GM Daniel [2 ƋƋ at CEMT]; same municipality at Casa do Mel. Light. Xii- 2015 [1 ♀ at CEMT]; Cuiabá. PARNA Chapada dos Guimarães. 13-xii-2008 [1 Ƌ at CEMT]; same data but xii-2015. Light. A Frolov [1 ♀ at CEMT].

Description (Holotypeı male). BL: 17 mmı PW: 10 mm. Colour: blackı shiny. Head: frontoclypealı genal and inter-ocular surfaces smooth. Gena borders slightly curved inward. Cephalic carina longer than wideı conical with rounded apex. Pronotum: pronotal disc shinyı lacking punctures having a round central lobe on anterior portion. Internal eye side with coarse deeply impressed punctures. Posterior margin with two rows of ocellate puncturesı interrupted medially. Metasternum: sides and margins of anterior lobe covered by long hair. Anterior portion of anterior lobe glabrous but bearing coarse and ocellate punctures. Setigerous punctures equally spaced at sides. Elytra: striae deeply impressed having fine punctures spaced by one time their diameter. First interstriae (near elytral suture) convex in relation to other interstriae which are flat. Interstriae disc lacking microsculpture with very fine puncture (20 x). Abdomen: sides of each ventrite excavatedı glabrous. Ocellate punctures concentrated at sides. Puncture of each ventrite interrupted medially as well as groove along the posterior margin of sixth ventrite. Aedeagus ( Figure 33 (j-l)): dorsallyı paramere apexes roundedı parallel; longitudinal excavation present taking the whole paramera length; basal-rounded excavation present; sub-apical spines presentı not narrowed posterior to spines. Laterallyı abrupt declivity from basis towards apex; having wide excavation. Ventrallyı basis with a single central tubercle; lateralrounded excavations present; subgenital plate emarginate posteriorly.

Morphological variation. males BL: 14 – 17 mmı PW: 8 – 10 mm. Male genitalia comparison allows us to identify three phenotypes. Larger males (re-described above) bear a strong and rounded pronotal lobe and well-developed cephalic horns with similar height of pronotum. Smaller males pronotum is simply convex while cephalic horn is produced in low transversal cephalic carina. Howeverı both male phenotypes and females have similar puncture and hair distribution pattern. Females BL: 14 – 18 mmı PW: 7 – 9 mm. Distinguished from males as follows: Head: fronto-clypeal surface striated. Coarse puncture present posterior to cephalic carina near both eyes. Cephalic carina lowı not bifurcated at apex. Pronotum: simply convexı lacking lobesı ocellate punctures with same pattern found on males but deeply impressed. Elytra: striae deeply impressedı punctures separated by twice their diameter. Blue sheen present near basis. Abdomen: sixth ventrite four times larger than fifth and bearing a weak protuberance at mid-portion.

Distribution. municipalities of Chapada dos Guimarães and Cuiabáı state of Mato Grossoı Brazil ( Figure 34 ).

Etymology. named after Bárbara Fernandes Beckerı who showed me the beauties of the type locality and of life itself.

Figures

Figure 33. D. arnaudi: (a) male dorsal habitus; (b) paramera dorsal view; (c) paramera ventral view; (d) paramera lateral view (grey arrow indicates the position of longitudinal excavation on lateral view). D. asenjoi: (e) male dorsal habitus; (f) paramera dorsal view; (g) paramera ventral view; (h) paramera lateral view. D. barbarae (i) male dorsal habitus; (j) paramera dorsal view (black arrow indicating slight medial constriction); (k) paramera ventral view; (l) paramera lateral view (black arrow indicates the surface of longitudinal excavation, which is smooth with fine punctures (see D. paschoali) and the differentiation of both species).

Figure 34. Distribution map of D. gardneriı D. aielloaeı D. asenjoiı D. arnaudiı D. Clypeatus and D. edmondsi.