Pereiraidium, 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 : 41-42

12. Pereiraidium , new genus

Diagnosis: Large species (5.5–6.1 mm), sides of head sinuate, clypeogenal margin not incised ( Figs. 88, 90). Male with two long frontal horns ( Figs. 30, 88), females with two poorly defined tubercles ( Figs. 31, 90). Pronotum with anterior bead distinct. Claws strongly toothed at base; protarsi with apical tarsomere modified in both sexes.

Description: Length 5.5–6.1 mm, body oval, elongated ( Figs. 30–31), color dark brown, opaque, lacking metallic sheen. Clypeus with two large, weakly defined teeth, separated by wide V-shaped emargination. Clypeus laterally sinuated, continuous with genal margin. Clypeofrontal and clypeogenal sutures indistinct; frons mesally with longitudinal concavity separating frontal structures (each side with either long horn or convexity, mesad to eyes), and transverse concavities anterior to eyes. Eyes, in dorsal view, wider than half of their length; interocular width approximately six times eye width ( Figs. 88, 90). Pronotum with distinct anterior bead (in some cases indistinct mesally), but lacking posterior one; lateral callosity indistinct; disc with setiferous punctures. Pronotum separated from hypomeron by distinct longitudinal carina. Hypomeron laterally with distinct longitudinal carina, mesoepimeron with distinct transverse carina. Elytral interstriae convex, each with two widely separated rows of setiferous punctures. Striae much deeper and wider on apical declivity. Pseudoepipleura gradually narrowed posteriorly, with uniseriate setiferous punctures along length and sparse setiferous punctures ventrally on the anterior half. Protibiae with three strong teeth, located on apical half, ventrally lacking scale-like setae. Mesotibiae and metatibiae longer than three times their apical width. Pygidium vertical. Parameres apically flattened ( Fig. 89), as long as third of phallobase length. Internal sac with strong sinuated and bent pseudoflagellum and two auxiliary lamellae. Coxites small, symmetrical and triangular. Spermatheca very elongated, slightly spiralled apically, gradually narrowed at both ends.

Sexual dimorphism: Males with strong frontal, upturned horns ( Figs. 30, 88) that can be as long as, or slightly longer than prothorax; horns with hairs similar to those on remainder of head at least on basal half ( Fig. 88); females with only two distinct convexities in place of horns ( Fig. 90). Pronotum of large males with flat anterior declivity ( Fig. 30), declivity absent or very slightly indicated in females ( Fig. 31). Metasternum concave in males and flat in females; and pygidium slightly longer in males.

Type species: Pedaridium almeidai Pereira, 1946 = Pereiraidium almeidai ( Pereira, 1946) , new combination.

Etymology: The name is after Padre Francisco Silvério Pereira, CMF (1912–1992), Brazilian scarabeidologist who described the single species here included in this genus. Gender neutral.

Distribution: South and southeastern Brazil (Rio Grande do Sul, Paraná and São Paulo ). Endemic to the southernmost part of the Brazilian Atlantic Forest province ( Fig. 108).

Remarks: The main apomorphies of this genus are the presence of horns in males and two frontal concavities in females, an anterior pronotal bead, and convex discal interstriae. It may be diagnosed also by the absence of the synapomorphies supporting Onoreidium , its sister-genus. See more remarks under Onoreidium .

Composition: Only the type species is known.

Material examined: