Dichotomius (Cephagonus) socius (Luederwaldtı 1929),

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 : 2293-2294

1.3.: Dichotomius (Cephagonus) socius (Luederwaldtı 1929) ( Figure 18 )

Pinotus socius Luederwaldt 1929 ı p. 127 (description)

Pinotus (Cephagonus) socius ı Luederwaldt 1930 ı p. 119

Pinotus (Cephagonus) socius ı Luederwaldt 1936 ı p. 216

Pinotus socius ı Blackwelder 1944 ı p. 208

Dichotomius (selenocopris) socius ı Vaz-de-Mello 2000 ı p. 193

Diagnosis. Dichotomius socius is distinguished from other species in the group by the following combination of characters: anterior portion of pronotum widely emarginated and covered with coarse punctures; cephalic horn carinate with rounded apexesı as large as tall; elytral striae weakly impressed and flat; female sixth ventrite emargination taking 1/third of pygidium length (contrary to D. ascanis and D. mundus in which the emargination is equivalent to one-fifth of pygidium length).

● LECTOTYPE of Pinotus socius (maleı here designated): P. socius Gillet Esp. Santo 1907 {whiteı handwritten} [MZSP];- PARALECTOTYPE of Pinotus socius (female): P. socius Gillet Esp. Santo 1907 {whiteı handwritten} [MZSP].

Non-type material. BRASIL: Bahia. Ubaíra. 13³06 ʹ 55 ” Sı 39 ³40 ʹ 03 ” W. 416 mosl. Pitfall. CMP Leite [2 ♀♀ at CEMT]; Espírito Santo: 1907 Pinotus socius Gillet [1 Ƌı 1 ♀ at CEMT]; Vargem Alta. ix-1995. JNC Louzada [1 ♀ at CEMT]; Santa Teresa. 1964 – 1967. C Elias. [4 ƋƋı 13 ♀♀ at DZUP]; Tijuco Preto. xi-1948. FJ Donor [1 ♀ at CEMT]; Minas Gerais: Berizal. Serra do Anastácio. 1375 mosl. Fezes humanas. 19-xii-2012. P Grossi [1 ♀ at CEMT]; Conceição dos Ouros. x-2002. EA Pereira [1 Ƌı 1 ♀ at CEMT]; Itamonte. 22³21 ’ Sı 44 ³48 ʹ W. 12.x-2009. T Vidaurre [1 Ƌ at CEMT]; Lavras. Poço Bonito. x-2001. P Grossi & FZ Vaz-de-Mello [2 ƋƋ at CEMT]; Nova Era. 1-iii-1995. JC Zanuncio [1 ♀ at CEMT]; São Gonçalo do Rio Abaixo. 11-x-2010. FM França [2 ƋƋı 1 ♀ at CEMT]. Viçosa. x-1981. F Fiuza [1m #ı 2 ♀♀ at CEMT]; same data but xii-1981 [1 ♀ at CEMT]; same data but x-1994. FZ Vaz-de-Mello [1 Ƌ at CEMT]; same data but Mata da Prefeitura. Luz UV. xii-1981. F Fiuza [2 ƋƋ at CEMT]; same data but x-1982 [1 ♀ at CEMT]; same data but Mata da Prefeitura. 20³48 ʹ 08 ” Sı 42 ³51 ʹ 31 ” W [2 ƋƋı 1 ♀]; same data but x-2011. J Chamorro-Rengifo [1 Ƌ at CEMT]; Paraná: Curitiba. Barigui. Xi- 1945. Ernesto [1 ♀ at DZUP]; Pato Branco. 26³11 ’ Sı 52 ³40 ʹ W. Fezes humanas. A Bugoni [1 ♀ at CEMT]; Rio de Janeiro: Cordeiro. x-1998. R Salgado [1 ♀ at CEMT]; Itatiaia. xii-1992. C Godinho [1 Ƌ at CEMT]; Nova Friburgo. xi-1993. E Grossi [1 ♀ at CEMT]; same data but xi 1997. E & P Grossi [1 ♀ at CEMT]; same data but xi- 1998 [1 Ƌ at CEMT]; same municipality but Macaé de Cima. xii-2005. E & P Grossi [1 Ƌ at CEMT]; Rio de Janeiro. Guaratiba. Iii-1956. J Guimarães [1 Ƌ at DZUP]; Rio de Janeiro. Floresta da Tijuca. x-1972. C Godinho [1 Ƌ at CEMT]; same data but xi-1972 [1 ♀ at CEMT]; same data but xii-1986 [1 ♀ at CEMT]; same locality but 15-x-2008. W Beiroz [1 Ƌ at CEMT]; São Paulo: Jundiaí. Serra do Japi. 23³14 ’ Sı 46 ³56 ʹ W. Fezes humanas. 1998. MIM Hernandéz [2 ♀♀ at CEMT].

Redescription. Colour: blackı shiny. Head: dorsal surface smooth with fine punctures. Gena borders straight. Clypeo-genal angle obtuse (110³) and with a slight protuberance. Cephalic carina with round apexı as wide as long. Coarse punctures present posteriorly to cephalic carina. Pronotum: pronotal disc delimited anteriorly by a central emargination with a pair of weak knobsı filled with coarse punctures. Anterior angles covered with fine punctures. Posterior margin with two rows of ocellate elliptical punctures. Metasternum: almost glabrousı margin of anterior lobe and sides with sparseı scattered setae. Punctures larger towards the sides of the metasternum. Elytra: striae shallowly impressed with well- defined punctures. Punctures separated by three times their diameter. Interstriae flatı semi-opaque lacking distinct microsculpture. Abdomen: sixth ventrite with strong groove all over its extension. Punctures of anterior margin of each ventrite interrupted medially. Aedeagus ( Figure 15 (e-g)): basal excavation shortı only taking the central portion. Paramera having one half the length of phalobasis. Ventral portion with two well- definedı rounded excavations on each paramera.

Morphological variation. males BL: 15 – 22 mmı PW: 8 – 14 mm. Larger males (redescribed above) bear central anterior emargination on pronotum and cephalic horns are well developed. Smaller males have a simply convex pronotal disc while the cephalic horn is produced in a low cephalic carina with two acute tubercles at the apex. Both phenotypes and females have similar punctuation and setae distribution pattern. Females BL: 16 – 17 mmı PW: 9 mm. Distinguished from males as follows: Head: fronto-clypeal surface striated. Coarse punctuation presents posteriorly to cephalic carina near both eyes. Cephalic carina transversalı forming a weak pair of tubercles. Pronotum: simply convexı lacking lobes. Elytra: striae deeply impressedı punctures separated by twice their diameter. Blue sheen near basis. Abdomen: sixth ventrite with a wide “ U “ shaped emarginationı equal to 1/third of the ventrite lengthı widely emarginated ( Figure 8 (e-f)).

Remarks. chosen Lectotype is the male because it has more informative characters and the diagnostic characters of this speciesı fixing its name. Luederwaldt (1929 ı 1930) commented on specimens sent to him by Staudinger in 1925 and a male and female specimens sent by Joseph Gillet in 1907ı all of which we have examined. In those publicationsı Luederwaldt stated that he had not found any diagnosis for Gillet ’ s specimens ( Luederwaldt 1929) and gave a brief description and comparison of this species with D. acutircornus ( Luederwaldt 1930) . Indeedı despite J. Gillet having labelled these specimensı he has never published a diagnosis for D. socius . The designation of one of Gillet ’ s specimens as the lectotype fixes the species name and is based on Luederwaldt citations of 1929 and 1930.

Figures

Figure 8. (a) Part of D. ascanius ventral portion evidencing metasternum puncture, cox – coxae ely – elytra, mes – mesepisternum, met – metasternum. (b) Pygidium of D. reichei (c) abdominal ventrites of a male of D. ascaniusı (d) abdominal ventrites of a female of D. ascaniusı (e) abdominal ventrites of a female of D. sociusı (f) detail of the sixth ventrite of a female of D. Socius.

Figure 15. D. ascanius: (a) male dorsal habitus; (b) female dorsal habitus; (c) female ventral habitus; (d) paramera dorsal view; (e) paramera ventral view; (f) paramera lateral view; (g) type labels.

Figure 18. D. socius: (a) larger male dorsal habitus; (b) smaller male dorsal habitus; (c) female dorsal habitus; (d) female ventral habitus; (e) paramera dorsal view; (f) paramera ventral view; (g) paramera lateral view.