Amphichroum monticola Cameron, 1928

Shavrin, Alexey V., 2021, New species and records of the genus Amphichroum Kraatz, 1857 from the Himalayan Region and Tibet (Coleoptera: Staphylinidae: Omaliinae: Anthophagini), Zootaxa 5082 (1), pp. 1-14 : 8-9

Amphichroum monticola Cameron, 1928

( Figs. 4 , 16 , 18–20 )

Amphichroum monticola Cameron, 1928: 558 ; Cameron 1930: 157

<?> Amphichroum monticola: Coiffait 1978: 114

Type material examined: Holotype, ♂ ( Fig. 4 ; dissected): ‘Type’ <round label with red margins>, ‘ Tibet: [underlined in yellow] Tropde. 11.000ft. 23.vi.1924. Maj.R.W.G.Hingston’ <printed>, ‘Everest Exp. | Brit.Mus. | 1924– 386.’ <printed>, ‘ Amphichroum alticola [sic!] Cam TYPE [handwritten by red]’ <handwritten in black>, ‘ Amphichroum | monticola Cameron, 1928 | teste Shavrin A.V. det. 2021’ <printed> ( BMNH).

Additional material studied: CHINA: 1 ♀: ‘ Tibet: Tropde. 11,000ft. 23.vi.1924. Maj.R.W.G.Hingston’, ‘ Everest Exp. Brit.Mus. 1924-386.’, ‘ A. monticola Cam’, ‘ M.Cameron Bequest. B.M.1955-147.’ ( BMNH); NEPAL : 1 ♂, 1 ♀: ‘NEPAL | Deorali – Bhandar env. 7.6.– 12.6.2012 lgt. E. Kučera’ (1 ♂: cSch; 1 ♀: cSh) ; 1 ♂: ‘NEPAL, Manaslu Mts. 28°22’N 84°29’E E slope of Ngali Khola Vall. 2000-2300 m, leg. Schmidt 15.V.2005 ’ ( NME) ; 13 ♂♂, 5 ♀♀: ‘ Nepal Manaslu Mts. E-slope, E Gupchi 2500-2700 m Danda , 22.V.2006 leg. J. Schmidt’ (9 ♂♂, 3 ♀♀: NME; 4 ♂♂, 2 ♀♀: cSh) ; 2 ♂♂: ‘NEPAL Manaslu Mts. E-slope E Gupchi Danda 2500-2700m 28°11’09N 84°49’09E 22.5.2006 leg. J. Schmidt’ (1 ♂: NME; 1 ♂: cSh) ; 1 ♂, 2 ♀♀: ‘NEPAL, Prov. Janakpur distr. Dolakha, upp. Simigau village , 2700-2800 m NN, 01.VI.2000 leg. J. Schmidt’ (1 ♀: NME; 1 ♂, 1 ♀: cSh) .

Redescription. Measurements (n=25): HL: 0.29–0.37; HW: 0.52–0.58; AL (holotype): 1.25; OL: 0.13–0.17; PL: 0.54–0.62; PW: 0.80–0.88; ESL: 0.86–1.02; EW: 0.92–1.23; AW: 0.88–1.25; MTbL (holotype): 0.52; MTrL (holotype): 0.48 (MTrL 1–4: 0.26; MTrL 5: 0.22); AedL: 0.62–0.68; TL: 2.65–4.00 (holotype: 3.00).

Habitus as in Fig. 4 . Head and pronotum yellow-brown to reddish-brown; elytra yellowish to brown; abdomen and antennomeres 4–11 brown to reddish-brown (some specimens with paler abdomen); mouthparts, antennomeres 1–3, legs and sometimes paratergites yellow. Clypeus with dense transverse microsculpture, middle portion of head with fine transverse and infraorbital portions with dense isodiametric or transverse meshes; pronotum without or with very fine, isodiametric microreticulation in medioapical and/or middle portion; scutellum with fine, transverse sculpture; abdomen with dense, transverse microsculpture on tergites IV–VI and dense isodiametric meshes on tergites VII–VIII. Head with fine and irregular punctation, denser in middle portion and sometimes slightly deeper between anteocellar foveae and eyes; punctation of pronotum dense, moderately large and deep, sometimes finer in middle and/or mediobasal portions or without punctures in mediobasal third; punctation of elytra dense, distinctly larger and deeper than that on pronotum; abdominal tergites with very indistinct, fine, irregular punctation. Forebody with moderately dense pubescence.

Head 1.5–1.7 times as broad as long. Distance between ocelli about one and a half times to twice as long as distance between ocellus and posterior margin of eyes. Antennomere 2 about as long as and broad as basal antennomere, 3 slightly shorter than 2, 4 distinctly shorter and slightly broader than 3, 5–7 disitinctly longer and broader than 4, 8–10 slightly broader and sometimes longer than 7.

Pronotum 1.4 times as broad as long, 1.4–1.5 times as broad as head, from the widest middle narrowed evenly anteriad and posteriad.

Elytra moderately short, 1.5–1.6 times as long as pronotum, slightly widened posteriad or somewhat parallelsided.

Male. Apical margin of abdominal tergite VIII straight. Apical margin of abdominal sternite VIII rounded. Median lobe moderately narrow ( Fig. 18–19 ), abruptly narrowed in preapical portion toward narrowly rounded ( Fig. 18 ) or subacute ( Fig. 19 ) apex; parameres slightly broadened apically, exceeding apex of median lobe, with two preapical setae; internal sac long, with oval ring-shaped structure in basal portion. Lateral aspect of aedeagus as in Fig. 20 .

Female. Apical margins of abdominal tergite VIII and sternite VIII rounded.

Comparative notes. Based on the coloration, length and proportions of the body, and the general shape of the aedeagus, A. monticola is similar to A. nepalicum and A. pindarense , from which it can be distinguished by the denser punctation of the pronotum, and details of the structure of the internal sac.

Distribution. The species is known from China (Tibet) and Nepal ( Fig. 16 ).

Bionomics. Specimens were collected at elevations from 2000 to 3352 m a.s.l.

Remarks. Coiffait (1978) recorded A. monticola from Bhutan and provided figures of the aedeagus, with narrow apex of the median lobe ( Coiffait, 1978: figures 4E, 4F), but these specimens requires re-examination. It is here recorded from Nepal for the first time.

Figures

FIGURES 1–7. Habitus of Amphichroum (males): 1—A. ahrensi (paratype), 2—A. altivagans (holotype), 3—A. anthobioides (lectotype), 4—A. monticola (holotype), 5—A. nepalicum (Nepal, Manaslu Himal), 6—A. pindarense (syntype), 7—A. telnovi (paratype). Scale bars: 1.0 mm.

FIGURES 15–17. Distribution of Amphichroum species in the Himalayan Region and Tibet: 15—A. ahrensi (circle), A. altivagans (triangle), A. anthobioides (squares), 16—A. monticola (circles), A. pindarense (triangles), A. telnovi (diamond), 17—A. nepalicum.

FIGURES 18–24. Aedeagus of Amphichroum monticola (18, 20: Nepal, Deorali, 19: Nepal, Khola Valley), A. nepalicum (21–22: Nepal, Manaslu Himal) and A. pindarense (23–24: Tibet, Rongshar Valley): 18, 21, 23—parameral view, 19—apical portion of aedeagus, parameral view, 20, 22, 24—lateral view. Scale bars: 0.1 mm.