Borneodeuterus, Kurbatov, Sergey A. & Cuccodoro, Giulio, 2015

Kurbatov, Sergey A. & Cuccodoro, Giulio, 2015, Revision of Neodeuterus Schaufuss and description of a new allied genus from Borneo (Coleoptera: Staphylinidae: Pselaphinae), Zootaxa 4006 (2), pp. 374-382 : 379-380

Borneodeuterus gen. n.

Type species: Borneodeuterus sannio sp. n., here designated.

Description. Body ( Fig. 12 ) 1.20 mm long, more oval in comparison with Neodeuterus ; integument shiny, with very fine and very sparse punctation on abdomen (distances between punctures several times wider than their diameters), punctures on pronotum fine and sparse (distances between punctures wider than their diameters) and on pronotum well-marked and denser (distances between punctures subequal to their diameters). Pigmentation uniform, yellowish-brown. Pubescence fairly long, suberect to erect, setae on medioapical portion of elytra parallel to sutural margin. Head in dorsal view subtriangular, with anterior margin rounded. Dorsal part of head with deep and broad square depression; tentorial foveae located at bottom of this depression. Lateral edges of front with deep and narrow postantennal notches (i.e., cuticular invaginations of lateral frontal edges) reaching anterior angles of vertexal depression to form additional pair of foveae. Each genal area with marked and smooth depression for reception of maxillary palpi. Posterior edge of head blunt, not forming ridge and lacking occipital depression. Posterior constriction of head dorsally with one median and pair of lateral longitudinal carinae; median carina simple and anteriorly not reaching vertexal depression. Antennal tubercles indistinct. Eyes well-developed, very prominent. Temples obsolete. Maxillary palpi ( Fig. 3 ) with palpomere II fairly regularly enlarged toward apex. Antennae composed of 10 antennomeres, distinctly divided into large scape and pedicel, 5 small and compact antennomeres of funicle, and conspicuously long club composed of three antennomeres (male); scape indistinctly notched apically. Pronotum with slightly biarcuate antebasal sulcus connecting median fovea with pair of lateral antebasal foveae; antebasal sulcus interrupted by two broad longitudinal ridges not reaching anteriorly middle of pronotal disc; additionally pronotum with three longitudinal sulci, short median one not connected to median antebasal fovea, and lateral ones connected to lateral antebasal foveae. Lateral pronotal margin evenly rounded, lacking tooth; basal margin with small median cariniform convexity and with row of six shallow depressions.

Prosternum with pair of lateral procoxal foveae and pair of anteroprosternal foveae; median carina well-marked, angular in lateral view; paranotal carina present. Each elytron with 4 basal equidistant foveae, located in two basal depressions, foveae 2 and 3 separated from each other by short longitudinal carina; internal depression connected to sutural stria entire and external depression connected to shortened discal stria; subhumeral fovea connected to marginal carina extending along entire elytral length; lateral elytral margins near subhumeral fovea with small sharp tooth; area in front of subhumeral fovea forming closed pentagonal subhumeral cell defined by elytral margin and carinae extending behind sharp humeral callus. Mesoventrite with pair of lateral foveae; median longitudinal carina absent. Mesocoxal cavities separated. Metaventrite with pair of lateral fovea and pair of lateral mesocoxal foveae; pair of longitudinal carinae present, extending from posterior edge of mesocoxal cavities to posterior metaventral margin. Paratergal-tergal suture distinct only on tergite 1 (IV); connection between tergite 1 and corresponding sternite 2 (IV) carinate; tergites 2–3 (V–VI) and corresponding sternites 3–4 (V–VI) fused. Tergite 1 shorter than tergites 2–3 combined, with pair of long longitudinal basal carinae separated by shallow mediobasal depression, and with pair of small mediobasal foveae. Tergites 2–3 each with pair of less distinct and more narrowed basal carinae. Sternite 2 with pair of basilateral foveae. Posterior edge of sternite 6 notched. Sternite 7 modified as genital plate covering genital opening.

Aedeagus with membranous median lobe and two asymmetrical parameres.

Female unknown.

Comparative diagnosis. Borneodeuterus possesses the structure of the genal area of Proterini sensu stricto, and within this group of genera uniquely shares with Neodeuterus the antennae composed of 10 antennomeres and the presence of a pentagonal subhumeral cell on each elytron. However it differs notably from Neodeuterus by the following characters:1) maxillary palpomeres 2 regularly enlarged toward apex, 2) antennae with long club composed of three antennomeres, 3) absence a small occipital depression, 4)pronotum lacking two irregular longitudinal ridges, and 5) pronotum lacking a lateral tooth. The conformation of protrochanter and of antennal club are most likely sexually dimorphic.

Distribution, Borneo.

Etymology. Combination of «Borneo» and « Neodeuterus » to underline the similarity between Borneodeuterus and Neodeuterus and the occurrence in Borneo. Gender masculine.

Figures

FIGURE 12. Habitus of Borneodeuterus sannio sp. n. Scale bar = 0.5 mm.

FIGURES 2 − 3. Right maxillary palpus in dorsal view of Neodeuterus admirandus Schaufuss (2) and Borneodeuterus sannio sp. n. (3). Scale bar = 0.1 mm.