Geodromicus amplissimus Shavrin, 2019

Shavrin, Alexey V., 2019, The crassipalpis species group of the genus Geodromicus Redtenbacher, 1857 (Coleoptera: Staphylinidae: Omaliinae: Anthophagini), Zootaxa 4686 (4), pp. 571-580 : 575-576

Geodromicus amplissimus Shavrin , sp.n.

( Figs. 2 , 8–9 , 12 )

Type material examined: Holotype ♂: ‘ CHINA (W Sichuan) (4) | Daxue Shan | river valley 5 km E | Kanding 2500–2800m | 30.03 N / 102.00 E | 20./ 23.V.1997 [D.] Wrase’ <rectangular label, printed>, ‘ Museum für Naturkunde | Berlin | Sammlung M. Schülke’ <rectangular label, printed >, ‘ HOLOTYPE | Geodromicus | amplissimus sp.n. | Shavrin A.V. des. 2019’ <red rectangulat label, printed> ( CSC) .

Paratypes (56 specimens): 3 ♂♂ [two specimens dissected], 2 ♀♀: same data as the holotype (1 ♂, 1 ♀: CS; 2 ♂♂, 1 ♀: CSC) ; 1 ♂ [dissected], 1 ♀: ‘ CHINA: Sichuan | Daxue Shan mts., 25 km SE | Kangding , 3200–3500 m, | 13.VI.–4.VII.2009, | leg. A. Plutenko’ <rectangular label, printed>, ‘ Museum für Naturkunde | Berlin | Sammlung M. Schülke’ <rectangular label, printed> (1 ♂: CS; 1 ♀: CSC) ; 1 ♀: ‘ CHINA: Sichuan | Daxue Shan Mts., 25 km SE | Kangding town , 13. VI.–4.VII.2009 | leg. A. Plutenko’ <rectangular label, printed> ( CA) ; 6 ♂♂ [two specimens dissected]: ‘ CHINA: W-Sichuan (13) | Daxue Shan, Hailuogou | Glacier Park , Camp 1. 2100m | 29.– 31.05.1997, M. Schülke’ <rectangular label, printed>, ‘ Museum für Naturkunde | Berlin | Sammlung M. Schülke’ <rectangu- lar label, printed> (2 ♂♂: CS; 4 ♂♂: CSC) ; 2 ♂♂: ‘ CHINA: W-Sichuan (15) | Daxue Shan, Hailuogou Glacier | Park , Camp 2, 2550– 2700 m | 29.35.16N, 102.01.53E | 30./ 31.05.1997, M. Schülke’ <rectangular label, printed>, ‘ Museum für Naturkunde | Berlin | Sammlung M. Schülke’ <rectangular label, printed> ( CSC) ; 1 ♂ [dissected], 3 ♀♀: ‘ CHINA Sichuan, Gongga | Shan, Hailuogou , head of | Glacier 1, 2850m 9.VII. [19]96 | 29°35N 102°00E C57’ <rectangular label, printed>, ‘collected by | A. Smetana, J. Farkač | and P. Kabátek’ (1 ♂: CS; 3 ♀♀: NSMT) ; 1 ♀: ‘ CHINA Sichuan, Gongga | Shan, Hailuogou , above | Camp 3, 3050 m 6.VII. [19]96 | 29°35N 102°00E C52’ <rect- angular label, printed> ( NSMT) ; 1 ♂ [without right apical antennomere and left antennomeres 5–11]: ‘ CHINA: Sichuan Gongga | Shan, Hailuogou , in front | of Glacier 1, 2850 m | 29°35N 102°00E, 7.VII. | 1998, A. Smetana [C76]’ <rectangular label, printed>, ‘1998 Chinese Expedition | J. Farkač, D. Král, | J. Schneider | & A. Smetana’ <rectangular label, printed> ( NSMT) ; 23 ♂♂ (4 specimens dissected), 11 ♀♀: ‘ CHINA (N-Yunnan) Diqing Tibet | Aut. Pref. , Deqin Co., Meili Xue | Shan , E-side, 14 km W Deqin | 28°27.47’N, 98°46.35’E, 2700 m’ <rectangular label, printed>, ‘small creek valley, glacier outlet | (under stones and gravel along | glacier stream) | 11.VI.2005 D.W.Wrase [09A]’ <rectangular label, printed>, ‘ Museum für Naturkunde | Berlin | Sammlung M. Schülke’ <rect- angular label, printed> (6 ♂♂, 2 ♀♀: CS; 17 ♂♂, 9 ♀♀: CSC). All paratypes with additional red rectangular printed label : ‘ PARATYPE | Geodromicus | amplissimus sp.n. | Shavrin A.V. des. 2019’.

Description. Measurements (n=57): HW: 1.14–1.45; HL: 0.60–0.87; OL: 0.30–0.32; TL: 0.13–0.16; AL (holotype): 4.05; PL: 0.91–1.25; PWmax: 1.51–2.00; PWmin: 1.37–1.64; ESL: 1.92–2.56; EW: 2.41–2.82; MTbL (holotype): 1.85; MTrL (holotype): 0.80 (MTrL 1–4: 0.50; MTrL 5: 0.30); AW: 2.26–2.75; AedL: 1.20–1.50; BL: 5.55–7.50 (holotype: 7.00).

Body reddish-brown to black; mouthparts, antennomeres and legs yellow-brown; apex of apical segment of maxillary palpi, basal portions of antennomeres 1–6, apex of tibia and tarsi yellow. Head with variable, irregular transverse meshes between antennal insertions, fine isodiametric microsculpture on infraorbital ridges, without or with indistinct, irregular transverse microreticulation in interocellar depression; pronotum with very indistinct or distinct, fine, isodiametric or transverse meshes except for median and postero-median portions. Habitus as in Fig. 2 .

Head 1.6–1.9 times as wide as long, distinctly more convex between ocelli and eyes; anterio-median depression moderately deep and wide, markedly narrowed basad and extending toward wide interocellar depression; temples slightly less than half as long as longitudinal length of eyes. Ocelli distinct; distance between ocelli as long as distance between ocellus and posterior margin of eye, or markedly longer. Punctation fine, irregular, and smooth, markedly denser on infraorbital ridges and sparser in interocellar depression. Apical maxillary palpomere 1.7 times as long as preapical segment. Antennae extending beyond apical fourth of elytra when reclined; lengths × widths of antennomeres (holotype): 1: 0.42 × 0.15; 2: 0.27 × 0.10; 3: 0.37 × 0.10; 4: 0.35 × 0.12; 5–7: 0.37 × 0.12; 8–9: 0.35 × 0.12; 10: 0.33 × 0.12; 11: 0.50 × 0.12.

Pronotum markedly convex, 1.6 times as wide as long, 1.3 times as wide as head, widest in apical third, with rounded anterior angles, distinctly protruded apicad, narrow posterior portion markedly longer than in G. crassipalpis ; median portion without impressions; laterobasal portions distinctly impressed and slightly reflexed. Punctation moderately dense and deep, sparser and finer in anteromedian third, markedly denser laterally, usually with median impunctate area.

Elytra slightly to significantly widened posteriad; hind margins straight or rounded. Punctation similar to that of pronotum, but slightly sparser.

Metatarsus more than twice as long as metatibia.

Abdomen with two distinct transverse tomentose spots in the middle of tergite IV.

Male. Posterior margin of tergite VIII straight. Posterior margin of sternite VIII slightly sinuate. Aedeagus ( Fig. 8 ) with moderately wide median lobe, in apical portion sharply narrowed toward narrowly rounded apex; parameres slightly widened apically, distinctly extending beyond apex of median lobe, with four short apical setae and additional very short setae along entire length of medial edge; internal sac with long narrow flagellum. Lateral aspect of aedeagus as in Fig. 9 .

Female. Posterior margin tergite VIII straight. Posterior margin of sternite VIII rounded.

Comparative notes. Based on the general shape of the aedeagus, G. amplissimus Shavrin , sp.n. is most similar to the Himalayan G. spadiceus , from which it differs by darker elytra, and slightly wider apical portions of median lobe and parameres. The new species differs from all the species of the crassipalpis group by the presence of very short setae on the medial edges of the parameres.

Etymology. The specific epithet is the superlative of the Latin adjective amplus (wide). It refers to the wide pronotum and elytra.

Distribution. The species is know from several locations in Daxue Shan and Gongga Shan ranges in Sichuan, and from Meili Xue Shan range in northern Yunnan ( Fig. 12 ).

Natural History. The specimens were collected from gravel on the banks of a river coming out from Glacier 1 (locality: C57), from flooded gravel banks of a river close to the glacier (locality: C76), by sifting wet moss on large fallen trees in a primary Abies forest with rich undergrowth of rhododendron (locality: C52), by sifting dead wood with fungi along a small river in a broadleaved forest with a small clearings and old trees (locality: 13), by sifting wet substrates between fallen trees and dead wood in an old mixed forest with huge old broadleaved and coniferous trees (locality: 15), and in Meili Xue Shan from under stones and gravel along a glacier stream (locality: 09A). The elevations range from 2100 to 3500 m a.s.l.

Figures

FIGURE 12. Distribution of Geodromicus amplissimus (black circles) and G. sp. (black square) in China.

FIGURES 1–3. Habitus of species of Geodromicus crassipalpis group: 1–G. crassipalpis (Uttarakhand), 2–G. amplissimus (holotype), 3–G. spadiceus (holotype). Scale bar: 1.0 mm.

FIGURES 4–10. Aedeagus of species of Geodromicus crassipalpis group (4–5: G. crassipalpis (Uttarakhand); 6–7: G. spadiceus (paratype); 8–9: G. amplissimus (paratype; Yunnan); 10: G. sp. (Gansu)): 4, 6, 8, 10–parameral view, 5, 7, 9–lateral view. Scale bar: 0.1 mm.