Amphichroum subelongatum Shavrin & Smetana, 2018

Shavrin, Alexey V. & Smetana, Aleš, 2018, New species of the genus Amphichroum Kraatz, 1857 (Coleoptera: Staphylinidae: Omaliinae: Anthophagini) from China, Zootaxa 4508 (3), pp. 377-402 : 398-399

Amphichroum subelongatum Shavrin & Smetana , sp.n.

( Figs. 33 , 37–38 , 41 )

Type material examined: Holotype ♂: ‘ CHINA: W-Sichuan 1999 | Ganzi Tibet. Aut. Pref., Luding Co. | W Erlangshan-Pass, 2600 m | 7 km SSE Luding, 29°51N, | 102°15E, Kiefer, Hasel, Blüten | 21. VI., leg. M. Schülke’ <rectangular label, printed>, ‘ Sammlung | M. Schülke | Berlin’ <green rectangular label, printed >, ‘ HOLOTYPE | Amphichroum | subelongatum sp.n. | Shavrin A. & Smetana A. des. 2018’ <red rectangular label, printed> ( CSC) . Paratypes: 3 ♂♂, 11 ♀♀: same data as the holotype (2 ♂, 2 ♀: CS; 1 ♂, 9 ♀♀: CSC) ; 1 ♀: ‘W-Sichuan (13) Daxue Shan, Hailuogou | Glacier Park , Camp 1, 2100m | 29.36.00N, 102.03.35E | 27.- 31.05.1997, M. Schülke’ <rectangular label, printed>, ‘ Amphichroum [handwritten] | sp. [handwritten] | det. Zanetti 2001’ <rectangular label, printed>( CSC) ; 1 ♀: ‘ CHINA (W Sichuan) (13) | Daxue Shan, Hailuogou | Glacier Park ( Gongga | Shan ) Camp. 1, 2100m | 29.36 N / 102.04 E | 27./28./ 31.V.`97 [D.] Wrase’ <rectangular label, printed> ( CSC) ; 1 ♀: ‘CHINA—SICHUAN | Juizhaigou | 15.6– 18.6.2011 | lgt. E. Kučera’ <rectangular label, printed> ( CSC) . All paratypes with red rectangular label ‘ PARATYPE | Amphichroum | subelongatum sp.n. | Shavrin A. & Smetana A. des. 2018’.

Description. Measurements (n=17): HW: 0.62–0.75; HL: 0.35–0.40; AL(holotype): 1.54; OL: 0.17–0.20; PL: 0.62–0.82; PW: 0.91–1.25; ESL: 1.12–1.51; EW: 1.22–1.50; AW: 1.10–1.45; MTbL(holotype): 0.77; MTrL(holotype): 0.57 (MTrL 1–4: 0.32; MTrL 5: 0.25); AedL: 0.85; TL: 3.50–4.80 (holotype: 4.05).

Forebody yellow-brown, sometimes with somewhat darkened head and disc of pronotum; mouthparts, antennomeres 1–3, legs, sometimes paratergites of abdomen yellow; antennomeres 4–11 brown; abdomen reddishbrown. Head with dense and moderately regular isodiametric microsculpture; middle part of neck with dense and coarse transverse microsculpture; pronotum with dense and small isodiametric microsculpture, slightly coarser than that on head; scutellum with distinct transverse meshes; elytra without or with indistinct isodiametric microsculpture, more distinct near scutellum. Head without punctation except for posterior portion between grooves and infraorbital ridges with several indistinct to distinct very small punctures (some paratypes only with several small punctures on posterior portions of infraorbital ridges); pronotum with small and deep punctation, distinctly sparser or missing on medio-basal portion and sometimes with impunctated longitudinal area; scutellum without or with several small punctures; abdominal tergites with irregular, very sparse small punctures.

Head 1.7–1.8 times as wide as long, flattened or slightly convex posteriorly between grooves and infraorbital ridges. Distance between ocelli subequal to distance between ocellus and posterior margin of eye. Apical segment of maxillary palp about 1.3 times as long as preceding segment. Length × width of antennomeres (holotype): 1: 0.17 × 0.05; 2: 0.15 × 0.05; 3: 0.15 × 0.04; 4: 0.12 × 0.05; 5–6: 0.13 × 0.05; 7: 0.13 × 0.06;8–9: 0.12 × 0.06;10: 0.12 × 0.07;11: 0.20 × 0.07.

Pronotum 1.4–1.5 times as wide as long, 1.4–1.6 times as wide as head, widest about middle, evenly narrowed both anteriad and posteriad, or slightly more narrowed posteriad; anterior angles rounded, slightly protruded; flattened and slightly explanate lateral portions moderately wide; some paratypes with indistinct oval impression in medio-basal third.

Elytra slightly wider than long and slightly widened apicad, usually reaching apical margin of abdominal tergite IV, 1.8 times as long as pronotum.

Metatibia 1.3 time as long as metatarsus.

Male ( Fig. 33 ). Protarsomeres 1–4 wide.Medial margin of apical part of protibia with two parallel rows of eight to ten short thorns; mesotibia slightly curved mediad, with dense row of fourteen to sixteen very short and wide peg setae. Apical margin of abdominal tergite VIII and sternite VIII slightly sinuate. Aedeagus ( Fig. 37 ) with median lobe gradually narrowed into short, wide apical portion with narrowly arcuate apex; parameres relatively wide, slightly widened apically, markedly exceeding apex of median lobe, with two pairs of apical and preapical very short setae; internal sac long, with fine thorns in apical and middle portion, and with a wide field of large thorns and a small oval structure, visible in lateral view ( Fig. 38 ) in basal portion.

Female. Protarsomeres 1–4 moderately narrow. Pro- and mesotibiae without modifications. Apical margin of abdominal tergite VIII and sternite VIII straight or rounded.

Comparative notes. Based on the size, coloration of the body and general shape of the aedeagus, the new species is similar to A. squamosum sp.n. and A. subaequale sp.n., from which it differs by indistinct punctation of the head, wider apical portion of the median lobe and details of the internal sac of the aedeagus.

Distribution. The new species is known from several localities ( Fig. 41 ) in Erlang Shan and Daxue Shan ranges in Sichuan, China.

Bionomics. Specimens were collected at elevations from 2100 to 2600 m a.s.l. Those from Erlangshan-Pass were taken from flowers together with specimens of A. squamosum sp.n. (see above).

Etymology. The specific epithet is the Latin adjective subelongatus, - a, - um (somewhat elongate). It refers to the elongate body of the new species.

Figures

FIGURE 41. Distribution of Amphichroum in China: A. angustilobatum sp.n. (black star), A. assingi sp.n. (white square with wide black margin), A. longilobatum sp.n. (white circle), A. maculosum sp.n. (white star), A. miaoershanum Watanabe, 1999 (circle with wide white margin), A. propinquum sp.n. (black square), A. rotundatum (white square), A. schuelkei sp.n. (black rhomb), A. squamosum sp.n. (black circle), A.subaequale sp.n. (white rhomb), A. subelongatum sp.n. (black triangle), A. tibetanum sp.n. (white triangle).

FIGURES 32–34. Habitus of Amphichroum (males): 32—A. subaequale sp.n. (paratype), 33—A. subelongatum sp.n. (paratype), 34—A. tibetanum sp.n. (holotype). Scale bar: 1.0 mm.

FIGURES 35–38. Aedeagus of Amphichroum subaequale sp.n. (35–36: paratype) and A. subelongatum sp.n. (37–38: paratype): 35, 37—parameral view,36, 38—lateral view. Scale bar: 0.1 mm.