Amphichroum squamosum 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 : 392-395

Amphichroum squamosum Shavrin & Smetana , sp.n.

( Figs. 19 , 27–28 , 30–31 , 41 )

Type material examined: Holotype ♂: SICHUAN: ‘ CHINA Sichuan, Kang- | ding (formerly Tatsienlu) | 2900m 2.VII.1996 | 30°03N 102°02E C48’ <rectangular label, printed>, ‘collected by | A. Smetana, J. Farkač | and P. Kabátek’ <rectangular label, printed >, ‘ HOLOTYPE | Amphichroum | squamosum sp.n. | Shavrin A. & Smetana A. des. 2018’ <red rectangular label, printed> ( NSMT) .

Paratypes: SICHUAN: 23 ♂♂ [two specimens dissected], 4 ♀♀: same data as the holotype (4 ♂♂, 1 ♀: CS; 19 ♂♂, 3 ♀♀: NSMT); 1 ♂ [specimen dissected]: ‘ China—Sichuan | 5-9 July 1995 | Kanding env., 2400-2800 m | Zd. Jindra lgt.’ ( NSMT); 1 ♂, 1 ♀: ‘ CHINA , Sichuan, Gongga | Shan , Hailuogou, above | Camp 3, 3000m 6. VIII. 96 | 29°35N 102°00E C53’, <rectangular label, printed>, ‘collected by | A. Smetana, J. Farkač | and P. Kabátek’ <rectangular label, printed> (1 ♂: CS; 1 ♀: NSMT); 1 ♂: ‘W SICHUAN 3-6.VII.1994 | 29.35N 102.00E 2900- 3200m | Gonggashan-HAILUOGOU | lgt. J. Farkač & D. Král’ ( NSMT); 2♂♂ [one specimen dissected], 2♀♀: ‘ 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> (1 ♂, 1 ♀: CS; 1 ♂, 1 ♀: CSC); 1 ♀: ‘ CHINA : N-Sichuan [CH12-21] | 49 km N Songpan, road S 301 km 114, | N Gongangling pass, 33°04'31''N, | 103°42'38''E, 3230 m, spruce forest, | litter, moss & mushrooms sifted, | 9.VIII.2012, M. Schülke’ <rectangular label, printed> ( CSC); 1 ♂, 1 ♀: ‘ CHINA : N-Sichuan [CH12-22] | Min Shan , pass 17 km NE Songpan, | 32°44'54''N, 103°43'43''E, 4080 m, | W-slope with scree and shrubs, | litter and moss sifted, 10.VIII.2012, | leg. M. Schülke’ <rectangular label, printed> ( CSC); 1 ♂ (specimen dissected): ‘ CHINA : N-Sichuan [CH12-23] | Min Shan , 17 km NE Songpan, E pass | 32°44'23''N, 103°44'31''E, 3920 m, | N-slope with rhododendron below rocks, | litter, moss, and grass roots sifted, | 10.VIII.2012, leg. M. Schülke’ <rectangular label, printed> ( CSC); 3 ♂♂ (one specimen dissected), 1 ♀: ‘ CHINA W. Sichuan ( Ganzi | Tibet. Aut. Pref. , Kangding Co.) | Daxue Shan , Mu Ge Cuo, upp. lake | 15 km NW Kangding, 3700m | 30°09N/101°52E | 27.VI.-5.VII.1999 D.W. Wrase’ <rectangular label, printed>, ‘ Sammlung | M. Schülke | Berlin’ <rectangular label, printed> ( CSC); 1 ♀: ‘ CHINA W. Sichuan ( Aba | Tibet. Aut. Pref. , Weizhou Co.) | Quionglai Shan , Wolong valley | 69 km WSW Dujiangyan, 3500m | 30°54N/102°59E (mix. forest) | 15.VII.1999 D.W. Wrase’ <rectangular label, printed>, ‘ Sammlung | M. Schülke | Berlin’ <rectangular label, printed> ( CSC); 1 ♂: ‘China centr . | Sichuan prov. | 10 km S from Siping | 20- 21.6.2005 | Ivo Jeniš leg.’ ( CA); 1 ♂: ‘ China centr . Sichuan prov. | 10 km S from Siping | 20- 21.6.2005 | Ivo Jeniš leg.’ ( CA). All paratypes with red rectangular label ‘ PARATYPE | Amphichroum | squamosum sp.n. | Shavrin A. & Smetana A. des. 2018’.

Description. Measurements (n=40): HW: 0.60–0.66; HL: 0.37–0.40; AL (holotype): 1.07; OL: 0.17–0.20; PL: 0.57–0.69; PW: 0.87–1.07; ESL: 1.15–1.35; EW: 1.17–1.29; AW: 1.07–1.26; MTbL (holotype): 0.65; MTrL (holotype): 0.55 (MTrL 1–4: 0.33; MTrL 5: 0.22); AedL: 0.68–0.78; TL: 2.90–3.95 (holotype: 3.25).

Forebody, antennomeres 4–11 and paratergites of abdomen yellow-brown, sometimes with somewhat darker posterior portion of head, neck and pronotum; mouthparts, antennomeres 1–3 and legs yellow; abdominal tergites reddish-brown to brown. Head with dense transverse microsculpture, with more or less rounded microsculpture on infraorbital ridges and neck; pronotum and scutellum with dense and irregular cellular microsculpture; prescutellar area of elytra with indistinct to distinct cells between punctures; abdominal tergites with very dense and distinct isodiametric microsculpture except for paratergites with somewhat smoothed sculpture. Lateral sides of neck with sparse, small and deep punctures; pronotum with dense small punctation except for midline. Head with two long black setae between anterior parts of eyes; pronotum with two pairs of very long black setae near anterior margin and four pairs of similar setae on lateral margins; elytra with additional five to eight pairs of very long black setae on lateral portions.

Head 1.6 times as wide as long. Ocelli very large, located at level of posterior margins of eyes near occipital furrow, distance between ocelli about as long as distance between ocellus and posterior margin of eye. Apical segment of maxillary palp 1.3 times as long as preceding segment, gradually narrowed apicad from middle. Antenna moderately long, reaching one-fourth of elytral length when reclined; length × width of antennomeres (holotype): 1: 0.13 × 0.05; 2: 0.12 × 0.05; 3: 0.12 × 0.04; 4: 0.08 × 0.04; 5–6: 0.09 × 0.06; 7–10: 0.11 × 0.06; 11: 0.17 × 0.06.

Pronotum convex, 1.5 times as wide as long, 1.4–1.6 times as wide as head, widest slightly above middle, markedly more narrowed posteriad than anteriad; anterior angles rounded, indistinctly protruded apicad; posterior angles widely rounded; some paratypes with indistinct longitudinal impression on medio-apical portion of disc and very slightly concave posterio-laterally.

Elytra slightly longer than wide, slightly widened apicad, reaching apical margin of abdominal tergite IV, about twice as long as pronotum, with widely rounded apical margins, truncated at suture.

Metatibia about 1.2 times as long metatarsus.

Male ( Fig. 19 ). Pronotum convex, wide. Protarsomeres 1–4 very wide. Medial margin of apical part of protibia with two parallel rows of five to eight short peg setae; mesotibia strongly curved mediad, with dense row consisting of twelve to seventeen very short and wide thorns. Abdominal tergite VIII and sternite VIII with straight apical margin. Aedeagus ( Fig. 27 ) wide basally, with median lobe widely attenuate around middle, anteriorly tapered into narrow apical portion with narrowly arcuate apex; parameres moderately narrow, distinctly exceeding apex of median lobe, with two pairs of apical and preapical very short setae; internal sac long, with elongated rows of thorns in apical half and with wide field of very wide, strongly sclerotized thorns in basal portion. Aedeagus laterally as in Fig. 28 .

Female. Pronotum less convex, markedly narrower. Protarsomeres 1–4 moderately narrow. Medial margin of protibia without peg setae; mesotibia without modifications, slender. Abdominal tergite VIII and sternite VIII with rounded apical margin.

Comparative notes. Based on the size, coloration, general shapes of the body and aedeagus, A. squamosum sp.n. is similar to A. miaoershanum Watanabe, 1999 (Guangxi) , A. subaequale sp.n. (Shaanxi) and A. subelongatum sp.n. (Sichuan). From A. miaoershanum it differs by the narrower body with less convex pronotum, by the wider median lobe of the aedeagus and longer parameres. From A. subaeguale sp.n. it differs by the more curved mesotibia in males, wider basal portion, median lobe and apex of the aedeagus. From A. subelongatum sp.n. it differs by the presence of well visible punctation of the head and narrower apical part of the aedeagus. From all these species, it differs by the pronotum sometimes with indistinct longitudinal impression, by the elytra slightly longer than wide and by the details of the internal sac.

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

Bionomics. Specimens were collected at elevations from 2400 to 4080 m a.s.l. They were taken from flowers of wild roses (C48), in primary Abies forest with rich undergrowth of rhododendrons by sifting various debris, leaf litter and moss accumulated on sandy flats of a creek (C53; locality CH 12-23: Fig. 31 ), in spruce forest by sifting litter, moss and mushrooms ( CH 12-21), in pine forest with hazel and flowers (Erlangshan-Pass, 7 km SSE Luding) and in shrubs by sifting litter and moss (locality CH 12-22: Fig. 30 ). Specimens from Erlangshan-Pass were collected together with specimens of A. subelongatum sp.n. (see below).

Etymology. The specific epithet is the Latin adjective squamosus, - a, - um (bearing scales), referring to the basal portion of the internal sac that may resemble scales.

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 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.

FIGURE 30–31.Type localities of Amphichroum squamosum sp.n. in the Min Shan range in Sichuan, China (photographs: M. Schülke (locality CH12-22, Fig. 30), V. Assing (locality CH12-23, Fig. 31)).