Dichotomius (Cephagonus) fernandosilvai, 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 : 2299-2300

2.4.: Dichotomius (Cephagonus) fernandosilvai new species

( Figure 23 )

Diagnosis. distinguished from the other species in the group by the following combination of characteristics: males ’ cephalic carina strongly transverseı larger than tallı slightly emarginated at apex; anterior portion of pronotum bearing coarse punctuation (as in D. filgueirasi of fissus group); pronotal margin serrate (as in D. baiano and D. filgueirasi ); males ’ pronotal disc with a pair of central knobs at anterior portion; posterior margin of elytra with elliptical punctures ( Figure 14 (d)) and elytra lacking microsculpture. This species resembles smaller males of D. filgueirasi (also occurring in the state of Pernambuco)ı differences are concentrated on the pronotal knobs ( D. filgueirasi tends to lack it) and differentiation by paramera.

● HOLOTYPEı male: BRASIL: Pernambuco: Caruaru. Parque Ecológico João Vasconcelos Sobrinho. Pitfall. 12-vi-2008. FAB Silva [at CEMT].

● PARATYPE: same data of Holotype [1 ♀ at CEMT].

Description (holotype). BL: 19 mmı PW: 12 mm. Colour: blackı shiny. Head: frontoclypeal surface smooth. Genal surface strongly wrinkled. Inter-ocular surface with coarse punctures. Gena borders straight. Cephalic carina larger than tallerı emarginated at apexı with striations at the base. Pronotum: borders serrate. Pronotal disc shinyı lacking punctures and with a central pair of knobs at anterior portion. Anterior excavation and anterior angles filled with coarse puncture. Posterior margin with two rows of elliptical punctures. Metasternum: sides and anterior portion of anterior lobe covered by dense red setae. Setigerous punctures equally spacedı where present. Elytra: striae weakly impressed with weak punctures. Punctures separated by twice their diameter. Interstriae flatı lacking microsculpture. Abdomen: glabrous and lacking distinct row of continuous punctuation along anterior margin of the ventrite. Aedeagus ( Figure 23 (d-f)): parameraı apexes rounded dorsallyı convergent; longitudinal excavation taking only 1/5 of paramera length and restricted to apex; basal excavations weakı transversalı reaching the sides of the paramera. Laterallyı with a subtle declivity towards the apex; excavation near to the posterior border occupying half of paramera length towards the base. Ventrallyı a pair of wideı round excavations; subgenital plate rounded at the base and widely emarginated at the apex.

Morphological variation. female BL: 19 mmı PW: 11 mm and distinguishable from the male by the following: Head: fronto-clypeal surface transversely wrinkled. Cephalic carina transversalı forming a weak pair of tubercles. Pronotum: punctuation coarser than that of malesı posterior margin with two defined rows of elliptical punctures. Pronotal borders strongly serrate. Elytra: striae deeply impressedı punctures separated by twice their diameter. Abdomen: sixth ventrite bearing a pair of triangular projections reaching the apical margin of the pygidium ( Figure 9 (b)).

Distribution. municipality of Caruaruı state of Pernambucoı Brazil ( Figure 20 ).

Etymology. named after Dr. Fernando Augusto Barbosa Silva (Universidade Federal do Paráı Brasil)ı who collected the holotype.

Figures

Figure 9. (a) Abdominal ventrites of a male of D. spadiceus. (b) ventrites of a female of D. spadiceus. (c) abdominal ventrites of a female of D. itatiaiaensisı (d) detail of C; (e) abdominal ventrites of a female of D. fissus. (f) Adbominal ventrites of a female of D. reichei. (g) Abdominal ventrites of a female of D. lucianomourai.

Figure 14. Types of punctures and head/pronotal disc surfaces: (a) smooth surface with fine puncture; (b) ocellate punctures type I; (c) elliptical punctures; (d) ocellate punctures type II; (e) fine punctures (pronotum) and coarse punctures (head, indicated by white arrow); (f) clypeus and gena surfacewrinkled, wrinkled.

Figure 20. Distribution map of the species in the D. fissus group.

Figure 23. D. fernandosilvai: (a) male dorsal habitus (Holotype); (b) female dorsal habitus; (c) female ventral habitus; (d) paramera dorsal view; (e) paramera ventral view; (f) paramera lateral view.