Amphichroum altivagans Cameron, 1941

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 : 4-5

Amphichroum altivagans Cameron, 1941

( Figs. 2 , 10–11 , 15 )

Amphichroum altivagans Cameron, 1941: 143

Type material examined: Holotype by monotypy (“Type in my collection”), ♂ ( Fig. 2 ): ‘Type’ <rounded label with red margin, printed>, ‘Kashmir | Khelanmarg | 10,000 ft. | vi-vii-1931 | Dr.Cameron’ <printed>, ‘A. | altivagans | TYPE [handwritten in red] Cam’ <handwritten in black>, ‘M.Cameron. | Bequest. | B.M.1955-147’. <printed>, ‘ Amphichroum | altivagans Cameron, 1941 | Shavrin A.V. det. 2021’ <printed> ( BMNH).

Additional material studied: 2 ♂♂, 2 ♀♀: ‘ Kashmir Khelanmarg 10,000 ft. vi-vii-1931 Dr.Cameron’, ‘ M.Cameron. Bequest. B.M.1955-147.’ ( BMNH) .

Redescription. Measurements (n=5): HL: 0.30–0.32; HW: 0.50–0.55; AL (holotype): 0.93; OL: 0.17–0.19; PL: 0.48–0.52; PW: 0.71–0.81; ESL: 1.00–1.07; EW: 1.00–1.05; AW: 0.87–0.97; MTbL (holotype): 0.57; MTrL (holotype): 0.41 (MTrL 1–4: 0.21; MTrL 5: 0.20); AedL: 0.60; TL: 2.42–3.01 (holotype: 2.55).

Habitus as in Fig. 2 . Forebody, mouthparts, antennomeres 1–3 and legs yellow (middle portion of head and neck slightly darker); abdomen yellow to dark-brown; two apical maxillary palpomeres and antennomeres 4–11 brown. Head with distinct, dense microsculpture, transverse on clypeus and isodiametric in middle portion and neck; pronotum with distinct isodiametric meshes, finer than in middle portion of head, without microreticulation in middle and/or mediobasal third; abdominal tergites with dense transverse microreticulation. Middle portion of head with fine and sparse punctation; punctation of pronotum dense, moderately large and deep, finer in mediobasal portion, sparser and finer in middle and/or mediobasal third (some specimens without punctures in mediobasal portion); punctation of elytra about as that on pronotum, but deeper, coarser in basal portion and sometimes finer in parascutellar portion and along suture; abdominal tergites without or with very fine and sparse punctation. Frontal portion of head with several long setae; pronotum and elytra covered by dense, long, semierect setation.

Head 1.6–1.7 times as broad as long, with basal part of clypeus slightly impressed; anteocellar foveae deep and long, reaching level of anterior margins of eyes. Distance between ocelli about one and a half times distance between ocellus and posterior margin of eyes. Antennomere 3 slightly narrower and about as long as 2, 4 slightly broader and shorter than 3, 5–6 distinctly broader than 4, 7–9 slightly shorter than 6, 10 slightly broader than 9, about as long as previous antennomere.

Pronotum 1.4–1.5 times as broad as long, 1.4 times as broad as head, widest in middle, slightly more narrowed anteriad than posteriad.

Elytra about as long as broad, twice as long as pronotum.

Male. Apical margin of abdominal tergite VIII more or less straight. Aedeagus ( Fig. 10 ) with wide basal portion, significantly narrowed apicad toward subacute apex; parameres narrow, slightly exceeding apex of median lobe, with one pair of short preapical seta; internal sac very long, with several large sclerotized teeth in preapical and middle portions. Lateral aspect of aedeagus as in Fig. 11 .

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

Comparative notes. Regarding the general shape of the narrow and elongate apical portion of the median lobe and the length of the narrow parameres, A. altivagans is similar to A. anthobioides and A. telnovi sp. n. From A. anthobioides it differs by the paler pronotum and elytra, and from A. telnovi sp. n. by the smaller body and longer elytra. It can be distinguished from both species by the shape of pronotum, from middle slightly more narrowed anteriad than posteriad, and by details of the structure of the internal sac.

Distribution. The new species is at present known only from the type locality ( Fig. 15 ) in Kashmir, India.

Bionomics. Specimens were collected at elevation 3048 m a.s.l.

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 8–14. Aedeagus of Amphichroum ahrensi (8–9: paratype), A. altivagans (10–11: Kashmir, Khelanmarg) and A. anthobioides (12, 14: syntype; 13: Nepal, Bajura): 8, 10, 12—parameral view, 9, 11, 14—lateral view, 13—apical portion of aedeagus, parameral view. Scale bars: 0.1 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.