Horniella loebli 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 : 54-56

18. Horniella loebli Yin and Li , new species

Figs 30 B, 32–33, 49D; Map 4

Type material (5 ♂♂, 10 ♀♀). Holotype, ♂, labeled ‘ THAILAND: Chiang Mai, Doi Suthep , 1450 m, 04.xi.1985, Burckhardt- Löbl / Holotype [red], ♂, Horniella loebli sp. n., det. Yin & Li, 2014, MHNG’ . Paratypes: 2 ♂♂, 1 ♀, same data as the holotype ; 1 ♀, same data except ‘ 1050 m, 02.xi.1985 ’ ; 2 ♀♀, same data except ‘ 1250 m, 06.xi.1985 ’ ; 1 ♀, labeled ‘ THAINALD, 15.ix.1986, Prov. Chiang Mai, Doi Suthep , 1215 m, P. Schwendinger’ ; 1 ♀, same data, except ‘ 670 m, 31.x.1986 ’ ; 1 ♂, 2 ♀♀, labeled ‘ THAILAND, Chiang Mai, Doi Angkhong , 10 km W Eang , 1650 m, 22.iv.1987, P. Schwendinger’ ; 2 ♀♀, same data, except ‘ 750 m, 17.x.1990 ’ ; 1 ♂, labeled ‘ Thailand, Huay Nam Dang, Mae Taeng Dist ., 1400 m, 17.xii.1990, P. Schwendinger’ . All paratypes are housed in MHNG, and each bears a yellow type label similar to that of the holotype except ‘ PARATYPE ♂ (or ♀)’.

Description. Male ( Fig. 30 B). Length 2.67–3.02 mm. Head slightly longer than wide, HL 0.62–0.67 mm, HW 0.58–0.64 mm; anterolateral genal projections ( Fig. 32 C) distinct, with well-defined anterolateral angulation; median sulcus between antennal tubercles short; scapes ( Fig. 32 B) slightly roundly expanded at lateral margins; clubs ( Fig. 32 A) formed by apical three moderately enlarged antennomeres; venter with short, strongly curved lateral spines ( Fig. 32 D). Maxillary palpomeres II stout, widest at middle. Each eye composed of about 35 facets. Pronotum about as long as wide, PL 0.58–0.64 mm, PW 0.56–0.59 mm. Elytra wider than long, EL 0.71–0.78 mm, EW 1.11–1.22 mm; shallow discal striae reaching apical 2/3 of elytral length. Lateral portions of metaventrite each with one elongate, deep cavity filled with dense setae. Protrochanters each with one long ventral spine, profemora ( Fig. 32 E) each with two ventral spines at base and basal 1/3, along with several tiny ventral denticles, protibiae ( Fig. 32 F) with tiny triangular apical spur, mesotrochanters, mesofemora ( Fig. 32 G), and mesotibiae ( Fig. 32 H) simple; tarsomeres II normal, not extending to beneath tarsomeres III. Abdomen large, AL 0.76–0.93 mm, AW 1.14–1.23 mm, tergite IV (first visible tergite) with vague median carina extending to apical 1/4 of tergal length, lateral discal carinae short, relatively thick, tergite V lacking median carina. Sternite IX ( Fig. 32 I) with wellsclerotized apical half, and membranous narrowed basal half. AeL 0.66–0.71 mm; aedeagus ( Figs 32 J–L, 33) with broad, slightly asymmetric median lobe narrowing at apex; endophallus composed of two elongate sclerites overlapping each other and one short sclerite at base on long ones.

Female. Similar to male in general appearance; each eye composed of about 35 facets; mesotibiae simple at apex. BL 2.72–2.94 mm, HL 0.62–0.64 mm, HW 0.55–0.59 mm, PL 0.55–0.61 mm, PW 0.55–0.61 mm, EL 0.64–0.73 mm, EW 1.09–1.19 mm, AL 0.91–0.96 mm, AW 1.17–1.25 mm. Genital complex ( Fig. 49 D) with transverse apical sclerite, and elongate membranous basal portion.

Differential diagnosis. Horniella loebli is the only member of the H. burckhardti group that has the males possessing two spines (usually one in other species) at the ventral margin of the profemora, and both sexes have a broad, deep cavity at the lateral portions of the metaventrite, which when combined with the aedeagal form, lead to ready recognition of this species.

Comments. Male genital segments of the populations from Doi Suthep ( Figs 32 J–L), Ang Khang ( Figs 33 A–B), and Huay Nam Dang ( Fig. 33 C) were dissected to determine the range of intraspecific variation. While slight differences are present in the form of aedeagal endophallus, other important characters, e.g., the presence of two ventral spines on the profemora, and the lateral cavities on the metaventrite are consistent among these populations.

Distribution. Thailand: Chiang Mai ( Map 4 ).

Collection notes. Adults were collected by Burckhardt and Löbl from leaf litter samples by sifting and use of Winkler-Moczarski extractors.

Etymology. The new species is named after Ivan Löbl (Geneva, Switzerland), in acknowledgment of his collection of many Horniella specimens used in the present study.

Figures

MAP 4. Distribution of Horniella species in Thailand.

FIGURE 30. Male habitus of Horniella species. A. H. khaosabap sp. n. B. H. loebli sp. n. Scales: 1.0 mm.

FIGURE 32. Male diagnostic features of Horniella loebli 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. Sternite IX. J. Aedeagus of holotype (Population from Doi Suthep), in dorsal view. K. Same, in lateral view. L. Same, in ventral view. Scales: 0.3 mm, except B, I = 0.1 mm.

FIGURE 33. Aedeagus of Horniella loebli sp. n., in dorsal (A, C) and lateral (B) views. A, B. Population from Doi Angkhang. C. Population from Huay Nam Dang. Scales: 0.3 mm.

FIGURE 49. Female genital complex of Horniella species, in dorsal view. A. H. intricata. B. H. kaengkrachan. C. H. khaosabap. D. H. loebli. E. H. prolixo. F. H. philippina. G. H. pilosa. H. H. smetanai. I. H. cibodas. Scales: 0.2 mm.