Horniella intricata 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 : 47-48

15. Horniella intricata Yin and Li , new species

Figs 27 A, 28, 49A; Map 4

Type material (2 ♂♂, 1 ♀). Holotype, ♂, labeled ‘ THAILAND: Mae Hong Son, Mae Lang , 600–700 m, 12.xi.1985, Burckhardt- Löbl / Holotype [red], ♂, Horniella intricata sp. n., det. Yin & Li, 2014, MHNG’ . Paratypes: 1 ♂, 1 ♀, labeled ‘ THAILAND: Chiang Rai Prov., Doi Tung , 1300 m, Schwendingen, 02.x.1992 ’ ( MHNG). Each paratype bears a yellow type label similar to that of the holotype except ‘ PARATYPE ♂ (or ♀)’.

Description. Male ( Fig. 27 A). Length 2.81–2.82 mm. Head slightly longer than wide, HL 0.60–0.61 mm, HW 0.55–0.61 mm; anterolateral genal projections ( Fig. 28 C) distinct, anterior margins roundly concave; median sulcus between antennal tubercles short; scapes ( Fig. 28 B) angularly expanded at basolateral margins; clubs ( Fig. 28 A) loosely formed by apical three moderately enlarged antennomeres; venter with pair of relatively thick lateral spines ( Fig. 28 D). Maxillary palpomeres II stout, widest near middle. Each eye composed of about 35–40 facets. Pronotum slightly longer than wide, PL 0.59–0.60 mm, PW 0.56–0.57 mm. Elytra wider than long, EL 0.78–0.82 mm, EW 1.14–1.20 mm; discal striae reaching apical 4/5 of elytral length. Protrochanters and profemora ( Fig. 28 E) each with one long ventral spine, protibiae ( Fig. 28 F) simple; mesotrochanters ( Fig. 28 G) with extremely short, apically blunt ventral spine, mesofemora and mesotibiae ( Fig. 28 H) simple; tarsomeres II normal, not extending to beneath tarsomeres III. Abdomen large, AL 0.85– 0.78 mm, AW 1.14–1.23 mm, tergite IV (first visible tergite) with distinct median carina extending to near posterior margin, lacking lateral discal carinae, tergite V lacking median carina. Sternite IX ( Fig. 28 I) with well-sclerotized apical half, and membranous narrowed basal half. AeL 0.66 mm; aedeagus ( Figs 28 J–L) with nearly symmetric median lobe, obliquely truncate at apex; endophallus complicated, composed of four major sclerites.

Female. Similar to male in general appearance; each eye composed of about 25 facets; profemora each with two ventral spines near base. BL 2.79 mm, HL 0.61 mm, HW 0.53 mm, PL 0.5 mm, PW 0.55 mm, EL 0.68 mm, EW 1.05 mm, AL 0.91 mm, AW 1.14 mm. Genital complex ( Fig. 49 A) weakly sclerotized, composed of broadly transverse, plate-like apical sclerite, and membranous basal portion.

Differential diagnosis. This species is placed as a member of the H. burckhardti group. The roundly concave anterior margins of the apicolateral genal projections, short and apically blunt ventral spine on the mesotrochanters, the nearly symmetric aedeagal median lobe with an obliquely truncate apex, and complicated structure of the aedeagal endophallus are shared with H. kaengkrachan (described below). These two species can be separated by the more distinctly expanded basolateral margins of the scapes, and the mesotibiae with simple apices in H. intricata , while H. kaengkrachan has the scapes with an indistinct lateral expansion, and a triangular apical projection at the apices of the mesotibiae.

Comments. The populations from Mae Lang and Doi Tung have a nearly identical aedeagal structure, and clearly belong to a same species.

Distribution. Thailand: Mae Hong Son, Chiang Mai ( Map 4 ).

Collection notes. The holotype was collected from leaf litter samples by sifting and use of Winkler-Moczarski extractors.

Etymology. The specific name refers to the complicated structure of the aedeagal endophallus.

Figures

MAP 4. Distribution of Horniella species in Thailand.

FIGURE 27. Male habitus of Horniella species. A. H. intricata sp. n. B. H. kaengkrachan sp. n. Scales: 1.0 mm.

FIGURE 28. Male diagnostic features of Horniella intricata 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 Mae Lang), in dorsal view. K. Same, in lateral view. L. Aedeagus of paratype (Population from Doi Tung), in dorsal view. Scales: 0.3 mm, except B, I = 0.1 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.