17. Horniella khaosabap Yin and Li, new species

Figs 30 A, 31, 49C; Map 4

Type material (2 ♂♂, 4 ♀♀). Holotype, ♂, labeled ‘ THAILAND: Chanthaburi, Khao Sabap Nat. Park, 150–300 m, 23–24.xi.1985, Burckhardt- Löbl / Holotype [red], ♂, Horniella khaosabap sp. n., det. Yin & Li, 2014, MHNG’ . Paratypes: 1 ♂, 4 ♀♀, same label data as the holotype (MHNG) . Each paratype bears a yellow type label similar to that of the holotype except ‘ PARATYPE ♂ (or ♀)’.

Description. Male (Fig. 30 A). Length 2.89–3.08 mm. Head slightly longer than wide, HL 0.59–0.62 mm, HW 0.55–0.56 mm; anterolateral genal projections (Fig. 31 C) weakly indicated; median sulcus between antennal tubercles very short; scapes (Fig. 31 B) lacking expansion at lateral margins; clubs (Fig. 31 A) formed by apical three enlarged oval antennomeres; venter lacking lateral spines (Fig. 31 D). Maxillary palpomeres II slightly broadened from base toward apex. Each eye composed of about 40 facets. Pronotum about as long as wide, PL 0.62–0.65 mm, PW 0.59–0.60 mm. Elytra wider than long, EL 0.74–0.75 mm, EW 1.19– 1.16 mm; discal striae reaching apical 3/4 of elytral length. Protrochanters simple, profemora (Fig. 31 E) each with two tiny ventral spine at base, protibiae (Fig. 31 F), mesotrochanters, mesofemora (Fig. 31 G), and mesotibiae (Fig. 31 H) simple, metatibiae (Fig. 31 I) with apical tuft of short setae; tarsomeres II normal, not extending to beneath tarsomeres III. Abdomen large, AL 0.94–1.06 mm, AW 1.19–1.20 mm, tergite IV (first visible tergite) with median carina extending to half tergal length, lacking lateral discal carinae, tergite V lacking median carina. Sternite IX (Fig. 31 J) with well-sclerotized apical half, and membranous narrowed basal half. AeL 0.56 mm; aedeagus (Figs 31 K–M) with symmetric median lobe, narrowing from apical 1/4 toward apex; endophallus lacking sclerite, composed of membranous structure with small denticles.

Female. Similar to male in general appearance; each eye composed of about 40 facets; profemora each with two ventral spines near base, lacking setose tuft on metatibiae. BL 2.93–3.26 mm, HL 0.61–0.65 mm, HW 0.56–0.58 mm, PL 0.64–0.67 mm, PW 0.59–0.61 mm, EL 0.74–0.78 mm, EW 1.19–1.22 mm, AL 0.94–1.16 mm, AW 1.23–1.28 mm. Genital complex (Fig. 49 C) with transverse apical sclerite, and elongate membranous basal portion.

Differential diagnosis. This species is placed in the H. hirtella group, and is most similar to H. prolixo described below. Males of these two species share distinct antennal clubs, and a more or less modified apical portion of the metatibiae. They can be readily separated by the more strongly developed antennal club, the modification on the metatibiae that are composed of a tuft of setae, and the much stouter form of the aedeagus in H. khaosabap males, while for H. prolixo the males have less distinct antennal clubs, the metatibiae have a broadly concave apical portion on the mesal margin, and the aedeagal form is much more slender.

Distribution. Thailand: Chanthaburi (Map 4).

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

Etymology. The specific epithet is taken from the type locality of the new species, the Khao Sabap National Park.