Neodeuterus Schaufuss, 1887

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 : 376

Neodeuterus Schaufuss, 1887

Neodeuterus Schaufuss, 1887: 151 ; type species: Neodeuterus admirandus Schaufuss, 1887 (designation by Lucas, 1920: 435).

Redescription. Body ( Fig. 1) 1.05–1.15 mm long, elongate and moderately convex; integuments shiny, mostly covered with punctation very fine and very sparse (distances between punctures several times wider than their diameters) or evanescent. Pigmentation fairly uniform, reddish-brown. Pubescence fairly short, recumbent, setae on medioapical portion of elytra converging posteriorly. Head in dorsal view subtriangular, with anterior margin rounded. Dorsal part of head with anteromedial area deeply depressed, that depression extending posteriorly to pair of large and deep tentorial foveae. Lateral edges of frons 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. Genal areas each with marked and smooth depression to receive maxillary palp. Posterior edge of head forming ridge, except median part bearing small rhomboidal occipital depression. Posterior constriction of head dorsally with one median and pair of lateral longitudinal carinae; median carina anteriorly bifurcate, with anterior arms forming posterior edges of occipital depression. Antennal tubercles indistinct. Eyes well-developed, very prominent in both sexes. Temples obsolete. Maxillary palpi ( Fig. 2 ) with palpomere II abruptly enlarged subapically. Antennae composed of 10 antennomeres, distinctly divided into large scape and pedicel, 6 small and compact antennomeres of funicle, and more (male, Fig. 4 ) or less (female, Fig. 5 ) conspicuous club composed of two antennomeres; scape markedly notched apically revealing basal stalk of pedicel. Pronotum with slightly biarcuate antebasal sulcus connecting median fovea with pair of lateral antebasal foveae; antebasal sulcus interrupted by two narrow irregular longitudinal ridges almost reaching anterior pronotal edge; additionally pronotum with three longitudinal sulci, short median one not connected with median antebasal fovea, and lateral ones connected with lateral antebasal foveae. Lateral pronotal margin near lateral fovea with distinct lateral tooth; posterior pronotal angles each with an acute tip, resembling lateral 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; medial carina well-marked, angular in lateral view; paranotal carina present. Each elytron with 4 basal foveae grouped in pairs in two basal depressions; 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 margin near subhumeral fovea with small sharp tooth; area in front of subhumeral fovea forming closed pentagonal subhumeral cell defined by elytral margin and carinae extended behind sharp humeral callus. Mesoventrite with pair of lateral foveae; median longitudinal carina absent. Mesocoxal cavities separated. Metaventrite with 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), less distinct and slightly shortened on tergites 2–3 (V–VI); connection between tergites 1–3 and corresponding sternites 2–4 (IV–VI) carinate. Tergite 1 about as long as tergites 2–3 combined, with pair of long longitudinal basal carinae separated by deep mediobasal depression (presence/absence of mediobasal foveae not studied). 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 in both sexes. Sternite 7 modified as genital plate covering genital opening (its structure slightly different between male and female).

Male secondary sexual characters: antennomere X about as broad as XI (in female intermediate between IX and XI); antennomere XI more elongate than that in female; protrochanter and protibia toothed. Aedeagus with thin-walled median lobe and two asymmetrical parameres.

Comparative diagnosis. Neodeuterus possesses the structure of the genal area and the shape of the female abdominal sternites 6 and 7 of Proterini sensu stricto ( Cuccodoro & Kurbatov 2006; Kurbatov & Cuccodoro 2009), but it is the only genus of this group with antennae composed of 10 antennomeres as well as a pair of long longitudinal ridges on the pronotum. Besides, it differs from already treated genera Proterus, Exoterus , Pareuplectops , and Euparops in the antennal club composed of two antennomeres, and in the presence of a closed pentagonal subhumeral elytral cell (open in Proterus and Exoterus, and absent in Euparops and Pareuplectops ). In addition, Neodeuterus differs from Proterus and Exoterus in the presence of the pronotal antebasal sulcus, paranotal carinae, and a pair of longitudinal metaventral carinae.

Distribution. Sumatra.

Figures

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.

FIGURES 4 − 11. Neodeuterus admirandus Schaufuss; antenna of male (4) and female (5); female abdominal sternite 7 (6) and 8 (7); male abdominal sternite 7 (8) and 8 (9); aedeagus in lateral (10) and dorsal (11) views. Scale bars = 0.1 mm; up = 4 − 9; down = 10 – 11.