Trichodromeus acutipenis Shavrin, 2021

Shavrin, Alexey V., 2021, Four new species of the genus Trichodromeus Luze, 1903 from Nepal and Pakistan (Coleoptera: Staphylinidae: Omaliinae: Anthophagini), Zootaxa 4991 (2), pp. 353-362 : 354-357

Trichodromeus acutipenis Shavrin , sp.n.

( Figs. 1 , 5–6 , 11 )

Type material examined: Holotype, ♂ [dissected]: ‘ NEPAL Langtang vall. | upp. Kyangching Gompa | near Khumjung 3880m | 29.7.[19]98’ <printed>, ‘Ankauf A. Dobbertin | Rostock, 2001 | Museum Dresden’ <printed>, ‘ HOLOTYPE | Trichodromeus | acutipenis sp.n. | Shavrin A. V. des. 2021’ <red, printed> ( SNSD).

Paratype: 1 ♂ [specimen without left antennomeres 8–11 and right antennomeres 7–11]: same data as the ho- lotype ( CS); 1 ♂ [specimen without left antennomeres 5–11], 6 ♀♀ [four specimens without apical antennomeres]: ‘ Nepal, Langtang valley, | upp. Kyangching gompa | near Khyimjung, 3900mNN | 29.7.1998; leg Sant.Tamang, Iman Lama, Kumar Bhun’ (1 ♂, 5 ♀♀: SNSD; 1 ♀: CS); 1 ♀: ‘ NEPAL Annapurna Himal | Modi Khola vall. 35- 3700m | 13-14.6.[20]00 leg. Schmidt’ <printed>, ‘Ankauf A. Dobbertin | Rostock, 2001 | Museum Dresden’ <print- ed> ( SNSD); 1 ♀: ‘ NEPAL W Dhaulagiri | N Jungla pass 4300–| 4500 m, 13.IX.2012 | 28°50’12’’ N, 82°55’55’’ E | leg. J. Schmidt’ <printed>, ‘collection | NATURKUNDE- MUSEUM ERFURT’ <yellow, printed> ( NME); 1 ♀: ‘ NEPAL 14/ 15.9.1999 | Rolwaling vall.3600- | 4000m, Beding to Na | leg. J. Schmidt’ <printed>, ‘Ankauf A. Dob- bertin | Rostock, 2001 | Museum Dresden’ <printed> ( SNSD). All paratypes with red printed label: ‘ PARATYPE | Trichodromeus | acutipenis sp.n. | Shavrin A. V. des. 2021’.

Description. Measurements (min-max; n=10): HW: 0.85–0.97; HL: 0.58–0.62; OL: 0.22–0.25; LT: 0.09–0.12; AL (holotype): 3.40; PL: 0.70–0.84; PWmax: 1.08–1.22; PWmin: 0.90–0.97; ESL: 1.54–1.61; EW: 1.54–1.77; MTbL (holotype): 1.27; MTrL (holotype): 0.47 (MTrL 1–4: 0.25; MTrL 5: 0.22); AW: 1.68–2.24; AedL: 0.61–0.63; BL: 4.50–5.60 (holotype: 4.75).

Body reddish-brown, sometimes elytra and abdomen slightly paler; mouthparts, antennae and legs yellow to yellow-brown (several paratypes with dark brown femora). Body glossy; head with distinct, moderately fine, dense, isodiametric microsculpture, sometimes coarser and denser in middle; neck with coarse transverse and/or isodiametric sculpture; pronotum with distinct, dense, transverse microreticulation, usually finer in mediobasal third; scutellum with fine transverse meshes or without them; abdomen with fine, transverse microsculpture. Pubescence of forebody white or yellow, relatively dense and semi-erect, longer on apical part of head; abdomen with fine, dense and decumbent pubescence. Habitus as in Fig. 1 .

Head 1.4–1.5 times as broad as long, flattened or slightly convex in middle, with stronger elevated portions between ocelli and eyes; frontal portion with slightly elevated supra-antennal prominences, with moderately deep and wide anterio-median depression, slightly narrowed and extended basad to level of anterior margins of eyes and sometimes indistinctly connected with interocellar depression; temples convex, about twice shorter than eyes; interocellar depression moderately deep, subtrapezoidal, separated from infraorbital ridges by distinct, slighty convergent latero-anteriad anteocellar foveae, reaching level of apical third of eyes. Eyes moderately large, strongly convex. Ocelli very small and sometimes indistinct, located at level of posterior margin of eyes, distance between ocelli about as long as distance between ocellus and posterior margin of eye. Punctation dense, moderately large and deep, sometimes denser and deeper in middle; neck without visible punctures. Maxillary palpomere 3 distinctly shorter than preceding segment, slightly widened apically, with very dense, long pubescence; apical palpomere about 1.4 times as long as and distinctly narrower than preapical segment, from middle slightly narrowed toward rounded or subacute apex. Antennae long, exceeding apical third or hind margins of elytra when reclined; basal antennomere moderately robust, long, distinctly more than three times as long as broad, antennomere 2 moderately short, slightly narrower than basal antennomere, 3 distinctly longer and slightly narrower than 2, 4–9 slightly longer and broader than 3, 10 slightly shorter than 9, apical antennomere about 1.3 times as long as 10.

Pronotum subtrapezoidal and distinctly transverse, slightly convex and moderately wide, 1.4–1.5 times as broad as long, distinctly broader than head, widest in anterior portion, with markedly rounded and slightly protruded apicad anterior angles, significantly narrowed posteriad toward obtuse posterior angles; narrowest basal part of pronotum moderately long, sometimes slightly concaved laterally; anterior margin widely rounded; posterior margin straight or slightly concaved; middle portion with moderately deep, narrow, longitudinal depression, connected with transverse, indistinct or deep mediobasal depression; lateral margins with very narrow border. Punctation regular, about as that in middle portion of head, sparser in middle portion and denser in medioapical third in some specimens, interspaces between punctures in middle as broad as an average diameter of two-three nearest pucntures, sometimes with elongate impunctate area in mediobasal third.

Scutellum moderately large, with widely rounded apex, with a few fine punctures in middle.

Elytra slightly convex, about as broad as long or slightly longer, significantly widened posteriad toward broadly rounded posterior angles; lateral margins flattened; hind margins widely rounded or somewhat straight. Punctation significantly denser, larger and deeper than that on pronotum, coarser and denser in mediobasal portion, finer and sparser along suture; some specimens slightly and irregularly elevated between punctures in middle. Wings fully developed.

Legs slender and long, with moderately wide femora; tarsi about 1/2 as long as tibia; apical metatarsomere slightly shorter than preceding four tarsomeres.

Abdomen wide, distinctly broader than elytra, convex, with two relatively large, transverse tomentose spots in middle of abdominal tergite IV and two smaller and sometimes indistinct, transverse spots in middle of abdominal tergite V; apical margin of abdominal tergite VII with narrow palisade fringe. Punctation very fine and dense, sometimes indistinct.

Male. Protarsomeres 1–4 very wide. Apical margin of abdominal tergite VIII straight. Apical margin of abdominal sternite VIII widely concaved. Aedeagus with moderately wide basal portion, slightly narrowed toward middle of median lobe, with moderately narrow apical portion and subacute apex; parameres narrow, slightly exceeding apex of median lobe, with four long apical setae and several short setae along inner margin of each paramere; internal sac narrow and moderately long, with very long flagellum, spirally folded in basal portion ( Fig. 5 ). Lateral aspect of aedeagus as in Fig. 6 .

Female. Protarsomeres 1–4 narrow. Apical margins of abdominal tergite VIII and sternite VIII rounded.

Comparative notes. Based on the general shape of the forebody and aedeagus, T. acutipenis sp.n. is similar to T. armatus ( Cameron, 1941) , known from Pakistan ( Cameron 1941, Zerche 1992), from which it can be distinguished by the paler coloration, smaller body, longer parameres with different features of the setation, and details of the internal sac.

Distribution. The species is known from several locations in central and eastern Nepal ( Fig. 11 ).

Etymology. The specific epithet is derived from the Latin acutus, – a, - um (pointed) and penis (penis). It alludes to the shape of the apical portion of the median lobe.

Figures

FIGURE 11. Distribution of Trichodromeus in Nepal: T. acutipenis (circles), T. jaegeri (square), T. kaliyuga (triangle).

FIGURES 1–4. Habitus of Trichodromeus: 1—T. acutipenis (holotype), 2—T. jaegeri (paratype), 3—T. kaliyuga (holotype), 4—T. trilobatus (paratype). Scale bar: 1.0 mm.

FIGURES 5–10. Aedeagus of Trichodromeus (5–6: T. acutipenis (holotype), 7–8: T. jaegeri (holotype), 9–10: T. kaliyuga (holotype): 5, 7, 9–parameral view, 6, 8, 10 lateral view. Scale bar: 1.0 mm.