Amphichroum schuelkei 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 : 391-392

Amphichroum schuelkei Shavrin & Smetana , sp.n.

( Figs. 18 , 24–26 , 29 , 41 )

Type material examined: Holotype ♂: ‘ CHINA: Yunnan, Nujiang Lisu Pref., | Gaoligong Shan , “Cloud pass” | 21 km NW Liuku, 25°58'21''N, | 98°41'01''E, 3150 m, from white | umbellifera, 2.IX.2009, | leg. M. Schülke [ CH 09- 22b]’ <rectangular label, printed>, ‘ HOLOTYPE | Amphichroum | schuelkei sp.n. | Shavrin A. & Smetana A. des. 2018’ <red rectangular label, printed> ( CSC) .

Paratypes: 23 ♂♂, 24 ♀♀: same data as the holotype (3 ♂♂, 3 ♀♀: CS; 20 ♂♂, 21 ♀♀: CSC); 1 ♀: ‘ CHINA (Yunnan) | Nujiang Lisu Aut. Pref., | creek valley 3 km SE Gongshan | 27°43'02''N / 98°41'27''E | 1450-1500 m (litter/moss, sifted) | 5. VI .2007 D.W.Wrase [20]’ ( CSC). All paratypes with red rectangular label ‘ PARATYPE | Amphichroum | schuelkei sp.n. | Shavrin A. & Smetana A. des. 2018’.

Description. Measurements (n=40): HW: 0.45–0.60; HL: 0.28–0.36; AL(holotype): 1.17; OL: 0.16–0.19; PL: 0.50–0.60; PW: 0.71–0.95; ESL: 0.93–1.25; EW: 0.95–1.35; AW: 0.82–1.25; MTbL(holotype): 0.58; MTrL(holotype): 0.52 (MTrL 1–4: 0.32; MTrL 5: 0.20); AedL: 0.60–0.66; TL: 2.20–3.85 (holotype: 2.72).

Head and pronotum yellow-brown; mouthparts, antennomeres 1–4, lateral and sometimes basal portions of pronotum, elytra, legs and sometimes apical segments of abdomen yellow; sometimes apical maxillary palpomere, antennomeres 5–11 and abdomen reddish-brown. Head with indistinct, dense transverse microsculpture; disc of pronotum without or with indistinct transverse microsculpture except for medio-basal portion; scutellum and abdomen with distinct isodiametric microsculpture. Posterior portion of head with very irregular and sparse small punctation, sometimes deeper and larger between grooves; pronotum with dense and moderately large punctation, sparser on medio-basal portion and sometimes with impunctated longitudinal area on anterior half; scutellum without or with several small punctures.

Head 1.6 times as wide as long. Distance between ocelli about one and half times as long as distance between ocellus and posterior margian of eye. Length × width of antennomeres (holotype): 1: 0.12 × 0.05; 2: 0.11 × 0.05; 3: 0.10 × 0.03; 4: 0.09 × 0.04; 5: 0.09 × 0.05; 6: 0.10 × 0.05; 7–9: 0.10 × 0.06;10: 0.11 × 0.07;11: 0.15 × 0.07.

Pronotum 1.4–1.5 times as wide as long, 1.5 times as wide as head, widest in middle, evenly narrowed both posteriad and anteriad, or slightly more narrowed posteriad than anteriad; some specimens with very indistinct short longitudinal impression on midapical third.

Elytra slightly wider than long, markedly widened apicad, about twice as long as pronotum.

Male ( Fig. 18 ). Protarsomeres 1–4 very wide. Medial margin of apical part of protibia with two parallel rows of six to eight short peg setae; mesotibia moderately strongly curved mediad, with dense row of sixteen to twenty short acute thorns. Apical margin of abdominal tergite VIII straight or rounded. Apical margin of abdominal sternite VIII slightly sinuate. Aedeagus ( Fig. 24 ) narrow, median lobe elongate, vaguely, widely attenuate in middle portion, narrowed into slender apical portion; internal sac ( Fig. 25 ) very long, with several moderate thorns in apical portion and with wide field of large thorns and with characteristic ring-like structure in basal portion. Aedeagus laterally as in Fig. 26 .

Female. Protarsomeres 1–4 moderately narrow. Protibia and mesotibia without modifications. Abdominal tergite VIII and sternite VIII with rounded apical margin.

Comparative notes. Based on the body size, coloration and general shape of the aedeagus, A. schuelkei sp.n. is most similar to A. pindarense and A. angustilobatum sp.n., from which it differs by the narrower median lobe of the aedeagus and different internal sac. Additionally, from A. angustilobatum sp.n. it differs by less distinct microsculpture of head, shorter antennomeres 4–10, more slender aedeagus and narrower apical portions of the longer parameres.

Distribution. The new species is known from two localities ( Fig. 41 ) in Gaoligong Shan in Yunnan, China.

Bionomics. Specimens were collected at elevations from 1450 to 3150 m a.s.l. They were taken from white umbelliform flowers ( Apiaceae ) (locality CH 09-22b: Fig. 29 ) and by sifting litter and moss (locality 20).

Etymology. Patronymic, the species is named to honour our colleague, Michael Schülke, Berlin, Germany, one of the collectors of the type specimens.

Figures

FIGURES 29. Type locality of Amphichroum schuelkei sp.n.in the Gaoligong Shan range, Yunnan (photograph: M. Schülke (locality CH09-22b)).

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 16–19. Habitus of Amphichroum (males): 16–A. propinquum sp.n. (holotype), 17–A. rotundatum sp.n. (holotype), 18–A. schuelkei sp.n. (paratype), 19–A. squamosum sp.n. (holotype). Scale bar: 1.0 mm.

FIGURES 24–28. Aedeagus of Amphichroum schuelkei sp.n.(24–26: paratype) and A. squamosum sp.n. (27–28: paratype): 24 (outline of internal sac shown as point line), 27–parameral view, 25–internal sac, 26, 28–lateral view. Scale bar: 0.1 mm.