Pseudacerus Raffray, 1895

Hlaváč, Peter, 2011, Contribution to the knowledge of the tribe Mastigerina (Coleoptera: Staphylinidae: Pselaphinae, Clavigeritae), with a description of a new genus from Borneo, Zootaxa 3070, pp. 51-59 : 52-53

Pseudacerus Raffray, 1895

Pseudacerus Raffray, 1895: 80 . Type species: Pseudacerus furcatus Raffray (by monotypy). Pseudacerus: Besuchet, 2008: 71 .

Description. Head triangular. Eyes very large, composed of dorsal and ventral parts connected by facets and completely covering temples. Head with large lateral antennal cavity able to fully accomodate antennae which are then not visible dorsally. Antennae three-segmented, antennomeres I and II minuscule, I slightly longer than II, both not visible dorsally, antennomere III large, about twice as long as wide, elliptically elongate, very obliquely truncate at apex, with dense long setae mainly on apical half and apex.

Pronotum about twice as wide as long, heptagonal, anterior angles can be ill-defined but always present, longest at middle, its base triangular, deeply recessed into elytra, widest at base at level of posterior angles, lacking fovea or sulci; scutellum not visible.

Elytra about twice as long as pronotum, longer than abdomen, with isodiametric structure mainly in their anterior part and evanescent posteriorly, with long and sparse golden setae present on part or whole surface, humeri carinate and protuberant or not.

Venter with prosternum matt, with microsculpture and few punctures and setae, procoxae contiguous; mesoventrite shiny, short, about half as long as metaventrite, its median part with large punctures, apical mesoventral process pointed, basal mesoventral process short and wide; metaventral process longer than mesoventral process, slightly rounded or truncate, mesocoxae separated, metaventrite on disc smooth, on sides with large punctures; metacoxae separated by large, truncate, metaventral process; metaventrite and first visible sternite (sternite III) with large impressions to accommodate meso- and metafemora.

Abdomen shiny. Composite tergite (IV–VI) of complicated shape, with large basal cavity which covers major part or even whole of its surface, with well-developed, basally wide paratergites bearing long and dense trichomes of different number and shape. Tergites VII and VIII visible or not. First visible sternite (III) much longer than sternites IV–VII combined, with median carina or obtuse keel and lateral deep or shallow depressions.

Legs short and flat.

Sexual dimorphism. In male mesofemora with long spine that is species-characteristic, mesotibiae with triangular, more or less developed obtuse teeth. Females with mesotibiae and mesofemora simple, lacking spines or teeth.

Distribution. Only two species, both from Malaysia (Pehang and Sabah), have been described so far, but many undescribed species are known from Thailand, Malaysia ( Sarawak), and Indonesia (Sumatra, Java, Bali) ( Besuchet 2008).