Scybalocanthon acrianus Silva & Valois, new species

(Figs. 1A, 3B, 4A, 5A, 6C)

Etymology. The specific name is a Latinization of the demonym for the Brazilian state of Acre and should be treated as an adjective.

Diagnosis. Specimens of S. acrianus are similar to those of S. chamorroi new species . in body coloration (Figs. 1A, F); eighth elytral stria lacking carina at the anterior portion; sigmoid shaped of the FLP sclerite (Figs. 5A, E); and endophallus with microbristles right beside the FLP sclerite (Figs. 5A, E). However, S. acrianus can be easily distinguished from S. chamorroi by the opaque body surface (Fig. 1A), and weakly impressed elytral striae (Fig. 3B).

Description. Body. Oval, lateral edges rounded. Surface opaque, completely microgranulate. Color. Pronotum, lateral portion of hypomera, and legs yellow or light brown. Other parts dark brown. Length. 6.0–7.0 mm. Thorax. Anterior angles of pronotum approximately 85°. Lateral margin regularly curved outward, not forming an angle at the middle portion. Elytra. Striae thin and shiny, weakly impressed (Fig. 3B), punctures inconspicuous. Eighth stria effaced at the basal third, lacking carina at the anterior portion. Aedeagus. Parameres symmetrical, obliquely truncate apically (Fig. 4A). Dorsal margin of parameres curved inward. Ventral margin of parameres curved inward at the basal portion and substraight from the medial to apical portions. SRP circular, with curved handle-shaped extension (Fig. 5A). FLP sigmoid shaped, with a set of microbristles right beside it (Fig. 5A). A+SA with two superposed and elongate sclerites (Fig. 5A). AS sigmoid-shaped (Fig. 5A).

Type material. Holotype. BRAZIL: ACRE: Rio Branco, UFAC [Universidade Federal do Acre], secondary forest, ii.1997, F.Z. Vaz-de-Mello— 1♂ (CEMT) . Paratypes. BRAZIL: ACRE: Rio Branco, UFAC [Universidade Federal do Acre], secondary forest, ii.1997, F.Z. Vaz-de-Mello— 3♀ (CEMT) . BOLIVIA: EL BENI, Guanay (12°31’S, 66°49’30’’W), xi.1992, L. Peña— 1♂ (CMNC) .

Distribution. Known from Brazil (Acre) and Bolivia (El Beni) (Fig. 6C). Endemism areas: Brazilian subregion: South Brazilian dominion: Rondônia province (see Morrone 2014; fig. 12).