Oryssomus rhombus sp. nov.

(Fig. 6)

Description of holotype (male). Length 5.07, width 3.84 mm. Form elongate oval, widest at middle of elytra, somewhat flattened dorsoventrally (Fig. 6 C). General color brownish yellow. Outline of pronotum and elytron discontinuous. Pronotum brownish yellow, with a transverse basal black spot, translucent at apex; finely, densely punctured; pubescence of semidecumbent yellowish hairs (Fig. 6 D). Elytra brownish yellow with a rhomboidal black spot on the middle of the dorsum (Fig. 6 A). Elytral punctures coarse, dense, slightly larger than on pronotum and sparse in the discal area. Antenna and mouthparts brownish yellow, hypomera and epipleura yellow, legs brownish yellow. Metaventrite finely, sparsely punctured medially and anteriorly; coarsely, densely punctured laterally and posteriorly with punctures large, often confluent (Fig. 6 B). Abdominal ventrites coarsely punctured, punctures separated by about a diameter or less, punctures becoming coarser laterally on first and second ventrite (Fig. 6 E). First abdominal ventrite with postcoxal line 2/3 distant from the posterior margin of the ventrite. Genitalia simple; basal lobe shorter than paramere, lateral margin thickened and abruptly widened in apical half, apex bluntly pointed; paramere slightly curved in lateral view, nearly parallel-sided (Fig. 6 G, H); sipho slightly sinuous and flattened, rounded apex (Fig. 6 F).

Female. Unknown.

Etymology. The name of this species refers to the shape of the macula in the middle of the elytra.

Discussion. Oryssomus rhombus sp. nov. differs from its congeners by its color, shape of spot and male genitalia.

Type material. “ Guyane Française,/ Bélvédère de Saül,/ 29.X.2010, vitre 1,/SEAG col.” “ ♂ ” [white label]. “ HOLOTYPE / Oryssomus rhombus /Almeida & Santos, 2014” [red label]. 1 ex. [MNHN].

Geographical distribution. Bélvédère de Saül, French Guiana (Fig. 15).