Silvinha, Vaz-De-Mello, 2008

Vaz-De-Mello, Fernando Z., 2008, Synopsis of the new subtribe Scatimina (Coleoptera: Scarabaeidae: Scarabaeinae: Ateuchini), with descriptions of twelve new genera and review of Genieridium, new genus, Zootaxa 1955, pp. 1-75 : 43-44

15. Silvinha , new genus

Diagnosis: Dark brown to black, shiny, with sparse setae only on sides and apices of elytra ( Fig. 34); clypeal teeth acute, emerging from below clypeal margin, which is sinuate mesally ( Fig. 91). Pseudoepipleura strongly narrowed posteriorly, forming sharp angle near metacoxal apex ( Fig. 9). Aedeagus with lateroapical region of parameres expanded and curved inwardly ( Fig. 92).

Description: Length 3.5–3.8 mm, body form elongate, oval ( Fig. 34), dark brown to black, shiny, without traces of metallic sheen. Clypeus with two very acute teeth, separated from clypeus by transverse carina delimiting clypeal margin; clypeal margin between teeth simply sinuate in the middle, with rounded to truncate lobe over each clypeal tooth; sides straight to lateral genal angle. Clypeofrontal suture inconspicuous, indicated only laterally, clypeogenal suture inconspicuous. Eyes, in dorsal view, as wide as half of their length, not narrowed posteriorly; interocular width approximately eight times eye width ( Fig. 91). Pronotum lacking anterior and posterior beads, with lateral callus very feebly indicated; separated from hypomeron by strong longitudinal carina. Hypomeron with strong lateral longitudinal carina, mesoepimeron lacking anterior transverse carina; metasternal disc smooth. Elytral interstriae on disc lacking rows of punctures and setae, flat; very few (at most three) setose uniseriate punctures present only apically. Mesal striae with enlarged punctures only apically. Pseudoepipleura without distinct separation from disc anteriorly, glabrous, sinuated near metasternal lateral lobe, strongly narrowed and strongly angulate near metacoxa ( Fig. 9). Protibiae with three lateral teeth, distributed along apical half, not denticulate basally, with ventral scale-like setae. Mesotibiae and metatibiae gradually widened to apex, apex as wide as fourth of their length. Metatarsi with basal tarsomere as long as 1.3 times the second one. Abdomen with pygidium vertical, transverse. Parameres smaller than half of phallobase length, laminate, divergent mesally and strongly convergent apically ( Fig. 92). Internal sac with a three-folded pseudoflagellum and two acessory lamellae. Coxites small, symmetrical, and triangular. Spermatheca C-shaped, bulbous at base and gradually narrowed apically, apex inwardly curved.

Sexual dimorphism: Males have protibiae with triangular apically and ventrally directed apicomesal tooth; the apical tarsomere modified to receive claws, and protarsi with ventral scale-like setae; protibiae slen- der and gently curved inwardly (almost straight and wider in females), metasternum concave (nearly flat in females), last abdominal sternite shorter than in females, and pygidium less transverse.

Type species: Silvinha unica new species (monotypy).

Composition: Monobasic.

Etymology: Named after my wife, Silvia ( Silvinha ) Altoé Falqueto. The name is feminine in gender.

Distribution: Southeastern Brazil ( São Paulo , Minas Gerais, and Rio de Janeiro states). Endemic to the southeastern part of the Parana Forest province in the Parana subregion ( Fig. 108).

Remarks: This genus is related to Trichillum , Besourenga , Eutrichillum , Degallieridium , and Feeridium , although its exact position in that group is not resolved yet. Its main autapomorphies are the absence of organized punctation in elytral discal interstriae, uniquely shaped pseudoepipleura and clypeal teeth. See more remarks under Besourenga .