O. Merkl szerk.: Folia Entomologica Hungarica 69. (Budapest, 2008)

Comparative remarks -The transverse pronotum and the very short elytra (about 1.5 times longer than pronotum) make this species unmistakable within the genus. Rismethus merkli sp. n. (Figs 2,5) Material examined - Holotype, male: "Malaysia, Pahang, Pulau Tioman, trail between Juara and Tekek, lowland rainforest, swept & beaten, 10-17.III.1995, No. 9, O. Merkl" (HNHM). Paratype, male: Malaysia, Pahang, Pulau Tioman, Kampung Juara, 9-17.III.1995, O. MERKL (CPG). Description - Length 2.1-2.2 mm; width 0.72-0.74 mm. Male (Fig. 2). Head brown to blackish; pronotum brownish ferruginous; scutellum blackish; elytra almost entirely ferruginous or darkened along suture, sides or in median part so that surface of elytra appearing maculate. Covered with sparse, whitish and thickened scales. Head with eyes narrower than anterior margin of pronotum; frons flat on vertex, moderately impressed at anterior margin, coarsely punctate. Antennae short, not reaching middle of pronotum, strongly from fourth antennomere; second antennomere cylindrical, twice as long as wide; third antennomere globose and short, as long as about half of second; fourth and fifth antennomeres triangular, strongly dilated outwards, wider than long; sixth to ninth antennomeres as long as wide; tenth antennomere cup-shaped, wider than the preceding; eleventh antennomere oblong-ovate, pointed apically, about twice as long as tenth. Pronotum as long as wide as or slightly wider than long, widest at middle, constricted immediately behind anterior angles, strongly convex on disc, gradually declivous at sides, nearly vertical at base; lateral carina crenulate in anterior third, visible throughout its whole length in dorsal view and not attaining anterior margin; sides gently and regularly arcuate, feebly sinuate and briefly emarginate before posterior angles, the latter short with apex pointed and directed outwards; punctures coarse, evenly distributed with shiny interspaces much smaller than puncture diameters. Scutellum quadrangular, with feeble median longitudinal carina. Elytra connate, 1.6 times longer than pronotum, and 1.5 times longer than wide, widest at anterior third, then narrowing toward apex, strongly convex on disc; striae deeply punctate, interstriac flat, punctate. Wings absent. Prosternai sutures deeply furrowed for about half of their length. Aedeagus as shown in Fig.5 (length: 0.362 mm). Female unknown. Bionomics - The holotype was swept in lowland rainforest, the paratype was collected at light in the village of Juara (O. MERKL, personal communication).