Horniella centralis Yin and Li

Yin, Zi-Wei & Li, Li-Zhen, 2014, Revision of the Oriental genus Horniella Raffray (Coleoptera, Staphylinidae, Pselaphinae), Zootaxa 3850 (1), pp. 1-83 : 11-12

1. Horniella centralis Yin and Li , new species

Figs 3 A, 4, 48A–B; Map 1

Type material (4 ♂♂, 9 ♀♀). Holotype, ♂, labeled ‘ CHINA: Border Shaanxi-Sichuan (Daba Shan) pass 20 km SSE Zhenping, 1700–1800 m, 31°44’N, 109°35’E, 09.vii.2001, A. Smetana [C96a] / HOLOTYPE [red], ♂, Horniella centralis sp. n., det. Yin & Li, 2014, MHNG ’ . Paratypes: 5 ♀♀, same data as that of the holotype ( MHNG) ; 1, ♂, same data as, except ‘leg. M. Schülke [C01-07C] / mixed forest, small creek valley, moss, bark (sifted) / Sammlung M. Schülke, Berlin / M. SCHÜLKE Coll. Staphylinidae , Pselaphinae , Hamotopsis sp. 1, S. Nomura det., 2005’ ( SNUC) ; 2 ♀♀, same data, except ‘small creek vall., young-dry mixed forest, leaf litt., mosssifted, Wrase [07]’ ( SNUC) ; 1 ♂, 2 ♀♀, labeled ‘ CHINA: S-Shanxi (Qinling Shan), pass on rd. Zhouzhi – Foping , 105 km SW Xi’an, N-slope, 1700 m, 33°48’N, 107°58’E, leg. M. Schülke [C01-02] / 3.vii.2001, small creek valley, mixed deciduous forest, moss (sifted) / Sammlung, M. Schülke, Berlin / M. SCHÜLKE Coll. Staphylinidae , Pselaphinae , Hamotopsis sp. 1, S. Nomura det., 2005’ ( pcMS) ; 1 ♂, same data, except ‘ 1990 m, 33°44’N, 107°59, leg. M. Schülke [C01-01] / 2.–4.vii.2001, small creek valley, mixed deciduous forest, bamboo, small meadows, dead wood, mushrooms (sifted)’ ( pcMS) . Each paratype bears a yellow type label similar to that of the holotype except ‘ Paratype ♂ (or ♀), ’.

Description. Male ( Fig. 3 A). Length 3.81–3.98 mm. Head longer than wide, HL 0.76–0.81 mm, HW 0.71–0.72 mm; anterolateral genal projections ( Fig. 4 C) distinct, anterior margins evenly concave; median sulcus between antennal tubercles short; scapes ( Fig. 4 B) slightly expanded at basolateral margins; clubs ( Fig. 4 A) loosely formed by apical three moderately enlarged antennomeres; venter with pair of thick lateral spines ( Fig. 4 D). Maxillary palpomeres II stout, broadened at middle. Each eye composed of about 30–36 facets. Pronotum about as long as wide, PL 0.78–0.79 mm, PW 0.74–0.77 mm. Elytra wider than long, EL 0.96–0.98 mm, EW 1.42–1.44 mm; discal striae reaching apical 2/3 of elytral length. Protrochanters and profemora ( Fig. 4 E) each with one distinct ventral spine, protibiae ( Fig. 4 F) each with long apical spur; mesotrochanters ( Fig. 4 G) each with one sharp ventral spine, mesofemora simple, mesotibiae ( Fig. 4 H–I) each with preapical row of small denticles on mesal margin, and short, apical projection; tarsomeres II normal, not extending to beneath tarsomeres III. Abdomen large, AL 1.31–1.40 mm, AW 1.46–1.50 mm, tergite IV (first visible tergite) with median carina barely indicated (population from Daba Shan) to extending to apical 1/3 of tergal length (population from Qinling Shan), lacking discal carinae, tergite V lacking median carina. Sternite IX ( Fig. 4 J) nearly oval, with well-sclerotized apical half and membranous basal half. AeL 0.83–0.87 mm; aedeagus ( Figs 4 K–M) with greatly asymmetric median lobe, right half of median lobe greatly protruding apicad in dorso-ventral view; endophallus composed of single elongate sclerite.

Female. Similar to male in general appearance; scapes not expanded at basolateral margins; each eye composed of about 30 facets; profemora each with two ventral spines near base, mesotrochanters lacking ventral spine. BL 3.57–3.80 mm, HL 0.73–0.76 mm, HW 0.64–0.67 mm, PL 0.74–0.79 mm, PW 0.73–0.74 mm, EL 0.87–0.93 mm, EW 1.39–1.41, AL 1.23–1.32 mm, AW 1.47–1.56 mm. Genital complex ( Figs 48 A–B) with trapezoidal apical part, and transverse, broad, disc-like basal part.

Differential diagnosis. This is the species upon which the H. centralis group is based. The males are most similar to H. dao (described below) by sharing the evenly concave anterior margins of the anterolateral genal projections, the slightly expanded basolateral margins of the scapes, the long apical spur of the protibiae, similar apical projection of the mesotibiae, and similar placement of the spines on the fore and mid legs. The two species can be separated by the right half of the aedeagal median lobe being greatly protruding apically, and the endophallus forming a single elongate sclerite in H. centralis , while H. dao has the left half of the aedeagal median lobe greatly protruding apically, and the endophallus has one long sclerite and another much shorter sclerite at the base of the longer one.

Comments. Differences in length of the median carina on tergite IV and the form of the aedeagal median lobe and endophallus between populations from Daba Shan and Qinling Shan are considered intraspecific variation.

Distribution. Northwest China: Shaanxi ( Map 1 ).

Collection notes. Adults were collected from sifted litters in wet, mixed deciduous forests.

Etymology. The specific name ‘ centralis ’ means ‘centrally situated’, referring to the type locality which is located in the central part of China.

Figures

MAP 1. Distribution of Horniella species in China.

FIGURE 3. Male habitus of Horniella species. A. H. centralis sp. n. B. H. confragosa sp. n. Scales: 1.0 mm.

FIGURE 4. Male diagnostic features of Horniella centralis sp. n. A. Antenna. B. Scape. C. Right half of head, in dorsal view. D. Head, in lateral view. E. Protrochanter and profemur. F. Protibia. G. Mesotrochanter and mesofemur. H. Mesotibia. I. Apical portion of mesotibia, enlarged. J. Sternite IX. K. Aedeagus of holotype (Population from Daba Shan), in dorsal view. L. Same, in lateral view. M. Aedeagus of one paratype (Population from Qinling), in dorsal view. Scales: 0.3 mm, except B, I, J = 0.1 mm.

FIGURE 48. Female genital complex of Horniella species, in dorsal view. A. H. centralis (Population from Daba Shan). B. H. centralis (Population from Qinling). C. H. hongkongensis. D. H. nakhi. E. H. sichuanica. F. H. himalayica. G. H. hirtella. H. H. asymmetrica. I. H. burckhardti. Scales: 0.2 mm.