Batricavus Yin & Li, 2011

Yin, Zi-Wei, Li, Li-Zhen & Zhao, Mei-Jun, 2011, Batricavus tibialis, a new genus and species of Batrisini from South China (Coleoptera: Staphylinidae: Pselaphinae), Acta Entomologica Musei Nationalis Pragae 51 (2), pp. 529-534 : 530-531

Batricavus Yin & Li gen. nov.

Type species. Batricavus tibialis Yin & Li sp. nov. (here designated).

Diagnosis. Head nearly rectangular, frontal rostrum lacking. Antennal club formed by terminal three to four antennomeres. Pronotum with distinct median and lateral longitudinal sulci, transverse antebasal sulcus present; with a pair of sub-anterior impressions in both sexes. Elytra with two basal foveae, discal stria present. Tergite IV longer than V–VII combined.

Description. Head with clypeus visible in dorsal view, arcuate at anterior margin. Frons densely and roughly punctate, concave medially, slightly raised above antennal tubercles. Vertex sparsely and shallowly punctate. Vertexal foveae well-defined, connected by complete reverse U-shaped sulcus. Eyes well-developed, prominent. Gular foveae close in transverse opening; gular carina present. Maxillary palpi with segments I minute, II pedunculate, III nearly triangular, IV largest, fusiform, broadened at mesal margin. Antennae 11-segmented; scape thick, club four-segmented in male and three-segmented in female. Pronotum with pair of sub-anterior foveiform impressions, pair of lateral antebasal foveae connected by transverse antebasal sulcus, both inner and outer pair of basolateral foveae present. Each elytron with two basal foveae, subhumeral fovea and lateral striae present, discal striae extending from basal foveae to near elytral apex. Proventrite with lateral procoxal foveae. Thorax with lateral mesoventral foveae straightly inserted, median mesoventral foveae widely separated, lateral mesocoxal foveae and pair of lateral metaventral foveae present. Abdomen narrower then elytra, rounded apically. Tergite IV largest, mediobasal foveae and basolateral foveae present; discal carinae short and indistinct, reaching one-fifth of tergal length, paratergites absent; segments V–VI very short, lacking foveae; VII larger, with pair of lateral foveae. Sternite IV with mediobasal foveae and pair of lateral carinae present; VI–VII short, subequal in length. Aedeagus well-sclerotized.

Remarks. Batricavus gen. nov. is close to Trisiniotus Jeannel, 1960 , Batriscenaulax Jeannel, 1958 and Physomerinus Jeannel, 1952 by the first antennomere lacking a trichome or a projection at the anterolateral margin, the aedeagus with a narrowed basal bulb of the median lobe, and an elongate and simple dorsal apophysis. Trisiniotus has the pronotum lacking a median longitudinal sulcus (except for one Sumatra species ( NOMURA 1991: 11) and three to five highly modified apical antennomeres in the male. Batriscenaulax and Physomerinus are both characterized by possessing a complete median sulcus on the pronotum coupled with the male sexual characters present on tergite IV, protibiae or metafemora. But the two genera are distinguished from each other only by the locations of the male sexual characters which potentially makes the validity of their generic conception questionable. Batricavus may be easily separated from the above genera by the presence of a pair of unique foveiform impressions in the anterior part of the pronotum in both sexes which is uncommon and has never been observed in any Asian batrisine genera.

Batricavus tibialis sp. nov. may be readily distinguished from other batrisine species also by the previous combination of male sexual characters except for the sub-anterior impressions on the pronotum, viz.: antennae with the apical four antennomeres modified, the metaventrite with two rows of median macrosetae, the protibae protuberant laterally in the apical 1/3, and the shape of the aedeagus.

Etymology. The generic name is a combination of ‘ Batri -’, a common stem used in Batrisini , and Latin word ‘ cavus ’, referring to the sub-anterior impressions on the pronotum. Gender masculine.