Horniella prolixo 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 : 60

20. Horniella prolixo Yin and Li , new species

Figs 34 B, 36, 49E; Map 4

Type material (2 ♂♂, 5 ♀♀). Holotype, ♂, labeled ‘ THAILAND: Chiang Mai, Mae Nang Kaeo , 900 m, 54 km NE Chiang Mai , Burckhardt- Löbl, 03.xi.1985 / Holotype [red], ♂, Horniella prolixo sp. n., det. Yin & Li, 2014, MHNG’ . Paratypes: 1 ♂, 5 ♀♀, labeled ‘ THAILAND: Chiang Mai, Doi Suthep , 1050 m, 05.xi.1985, Burckhardt-Löbl’ ( MHNG) . Each paratype bears a yellow type label similar to that of the holotype except ‘ Paratype ♂ (or ♀)’.

Description. Male ( Fig. 34 B). Length 2.95–3.02 mm. Head slightly longer than wide, HL 0.61–0.64 mm, HW 0.57–0.58 mm; anterolateral genal projections ( Fig. 36 C) weakly indicated; median sulcus between antennal tubercles conspicuously short; scapes ( Fig. 36 B) lacking expansion at lateral margins; clubs ( Fig. 36 A) formed by apical three enlarged oval antennomeres; venter lacking lateral spines ( Fig. 36 D). Maxillary palpomeres II slightly broadened from base toward apex. Each eye composed of about 45 facets. Pronotum longer than wide, PL 0.67–0.68 mm, PW 0.58–0.61 mm. Elytra wider than long, EL 0.76–0.78 mm, EW 1.17–1.19 mm; discal striae reaching apical 4/5 of elytral length. Protrochanters simple, profemora ( Fig. 36 E) each with one tiny ventral spine, along with several smaller triangular denticles near base, protibiae ( Fig. 36 F), mesotrochanters, and mesofemora ( Fig. 36 G) simple, mesotibiae ( Fig. 36 H) with small apical projection, metatibiae ( Fig. 36 I) with apical half broadly concave at mesal margins; tarsomeres II normal, not extending to beneath tarsomeres III. Abdomen large, AL 0.91–0.92 mm, AW 1.16–1.20 mm, tergite IV (first visible tergite) with median carina extending to more than half of tergal length, lacking lateral discal carinae, tergite V lacking median carina. Sternite IX ( Fig. 36 J) elongate, well-sclerotized. AeL 0.62 mm; aedeagus ( Figs 36 K–M) with elongate, nearly symmetric median lobe, apex rounded; endophallus lacking sclerite, composed of elongate membranous structure with many small denticles.

Female. Similar to male in general appearance; each eye composed of about 40 facets; profemora each with two short ventral spines near base, metatibiae lacking modification. BL 3.21–3.28 mm, HL 0.64–0.67 mm, HW 0.58–0.61 mm, PL 0.67–0.71 mm, PW 0.59–0.65 mm, EL 0.79–0.87 mm, EW 1.20–1.31 mm, AL 1.03–1.11 mm, AW 1.28–1.31 mm. Genital complex ( Fig. 49 E) composed of transverse apical sclerite, and elongate membranous basal portion.

Differential diagnosis. This species is placed as a member of the H. hirtella group. Males share with H. khaosabap the distinct antennal clubs, and more or less modified apical portion of the metatibiae. These two species can be readily separated by the less distinct antennal clubs, the metatibiae have a broadly concave apical portion on the mesal margin, and the aedeagus is slenderer in H. prolixo , while the antennal clubs are more strongly developed, the metatibiae have a tuft of setae at the apical portion, and the form of the aedeagus is much stouter in H. khaosabap .

Distribution. Thailand: Chiang Mai ( Map 4 ).

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

Etymology. The specific name ‘ prolixo ’ means ‘to extend in space, elongate’, referring to the elongate aedeagal median lobe of the new species.

Figures

MAP 4. Distribution of Horniella species in Thailand.

FIGURE 34. Male habitus of Horniella species. A. H. phuphaman sp. n. B. H. prolixo sp. n. Scales: 1.0 mm.

FIGURE 36. Male diagnostic features of Horniella prolixo 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. Metatibia. J. Sternite IX. K. Aedeagus, in dorsal view. L. Same, in lateral view. M. Same, in ventral 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.