Trichodromeus pusillus Coiffait, 1983

Shavrin, Alexey V., 2012, On the taxonomic placement of Geodromicus pusillus Coiffait, 1983 (Coleoptera: Staphylinidae: Omaliinae), Zootaxa 3552, pp. 66-68 : 66-68

Trichodromeus pusillus Coiffait, 1983 comb. n.

( Figs. 1−3 )

Geodromicus pusillus Coiffait, 1983:279

Type material. Holotype of Geodromicus pusillus , male: [North India] ‘Cachemire [Kashmir] 8-80 Rohtang Pass 4000 m G.M[eurgues].—G. L[edoux].’, ‘TYPE’ <printed red label>, ‘ Geodromicus pusillus H. Coiffait 1981 ’ ( MNHNP); Paratypes of Geodromicus pusillus , 2 males, 1 female: same labels as the previous except label ‘Paratype’ <printed red label> ( MNHNP); Paratypes of Geodromicus pusillus , 1 male, 1 female: ‘Cachemire, VIII.79 Pahalgam 3800 Sheshnag G.M[eurgues].—G.L[edoux].’, ‘Paratype’ <printed red label>, ‘ Geodromicus pusillus H. Coiffait 1981 ’ ( MHNP).

Additional material. 3 males, 3 females: Cachemire, Godasar, 21.7.81, G. Ledoux (CT, CS); 1 male: Cachemire, Lac de Gangabal, 25.7.81, G. Ledoux leg. (CT); 1 female: Cachemire, Gangabal, 27.7.81, G. Ledoux (CT); 2 females: Cachemire, Glacier Harmukh, 25.7.81, G. Ledoux (CT).

Redescription. Measurements in mm (n=10). Maximum width of head including eyes: 0.6–0.68; length of head (from base of labrum to neck constriction along the head midline): 0.3–0.4; length of antenna: 1.5–1.6; longitudinal length of eye: 0.14–0.16; length of temple (from posterior margin of eye to neck constriction): 0.1; length of pronotum: 0.64–0.66; maximum width of pronotum: 0.8–0.86; minimum width of pronotum: 0.7–0.72; sutural length of elytra (length of elytra from apex of scutellum to posterior margin of sutural angle): 1.04–1.16; maximum width of elytra: 1.22–1.34; width of abdominal segment IV: 1.2–1.34; length of aedeagus: 0.6. Total length (from the base of labrum to the apex of abdomen): 3.7–4.4.

Habitus as in Fig. 1 . Dark brown to black; elytra, base and hind angles of pronotum brown; mouthparts, antennae, ocelli and legs brownish yellow. Pubescence very fine accumbent, white; pubescence of head longer, decumbent.

Head large, slightly transverse (twice as wide as long), with relatively large prominent eyes; eyes 1.6–1.7 times longer than temples; temples not extremely wide, convex; anteocellar depression deep; ocelli small, well visible, distance between ocelli 1.5 times the distance between ocellus and posterior margin of eye. Punctation very sparse, and irregular; interstices between punctures with well-defined microsculpture; clypeus glossy, without punctures or microsculpture. Maxillary palpi long, segment II curved in basal part and expanded to apex, segment III shorter than II and with long pubescence, segment IV slightly narrower than previous, and gradually tapered to apex from the anterior third of its length. Antennae relatively short, thick, reaching 1/3 length of elytra; antennal segments II −XI with the same thickness, antennomere IV slightly shorter than antennomeres III and V, antennomere XI 2.1 times longer than previous; length/ width of antennomeres are: I, 0.18 × 0.09; II −III, 0.14 × 0.08; IV, 0.12 × 0.08; V −VIII, 0.13 × 0.08; IX −X, 0.12 × 0.08; XI, 0.26 × 0.08.

Pronotum transverse, convex, approximately as wide as head, 1.2 times wider than long, gradually narrowed posteriorly from widest anterior part and forming distinctly right angles, with transverse impression at base and the hind angles; punctation denser than that on head, evenly distributed and deep, distance between punctures as large as diameter of 1–2 punctures; interstices between punctures with isodiametric microsculpture. Scutellum triangular, without punctures, with distinct isodiametric microsculpture. Elytra trapezoidal, 1.6−1.7 times longer than pronotum, slightly convex and slightly widened to apex, posterior angles broadly rounded; punctation regular, punctures larger and deeper than those of pronotum, distance between punctures 1−2 times as large as diameter of a puncture; interstices between punctures without microsculpture. Wings fully developed.

Abdomen convex, as wide as elytra; abdominal tergites with fine punctation and with distinct isodiametric microsculpture; tergites IV–V with paired tomentose patches.

Male. Protarsi with dilated tarsomeres, profemur widened, inner edge of all tibiae with rows of small thick spines. Sternite VIII with small rounded emargination. Aedeagus ( Figs. 2 ) relatively short and wide, parallel in median part, base of bulbus large, median lobe strongly tapered from middle towards apex; endophallus with long flagellum, forming large spiral in basal part and with parallel structures in apical part, with pair of curved apically sclerotized appendages; parameres very thin, not reaching the apex of aedeagus, with four setae on each apex. Aedeagus laterally as in Fig. 3 . Female. Protarsi with tarsomeres less dilated, profemur not widened, and inner edge of tibia without spines. Sternite VIII without emargination, and rounded apically.

Comparative notes. T. pusillus Coiffait differs from all known species of the genus by the significant smaller body, thick antennae, less expanded temples and by the shape and internal structures of the median lobe of the aedeagus.

Figures

FIGURES 1 – 3. Trichodromeus pusillus: 1 — habitus, 2 — aedeagus, ventral view, 3 — aedeagus, lateral view. Scale bars: 1: 2.0 mm, 2, 3: 0.1 mm.