Horniella aculeata Yin & Li

Yin, Zi-Wei & Li, Li-Zhen, 2015, Revision of the Oriental genus Horniella Raffray (Coleoptera, Staphylinidae, Pselaphinae) - Supplementum 1, ZooKeys 506, pp. 109-118 : 110-111

Taxon classification Animalia Coleoptera Staphylinidae

Horniella aculeata Yin & Li sp. n. Figs 1A, 2, 5A

Type material

(2 ♂♂, 4 ♀♀). Holotype: China: ♂, labeled 'Mengla Ziranbaohuqu {勐腊自然保护区}, (Xishuangbanna) {西双版纳}, S. Yunnan, China, Sept. 13th, 1993, Coll. Y. Watanabe / HOLOTYPE {red} ♂, Horniella aculeata sp. n., det. Yin & Li, 2015, NSMT’ (NSMT). Paratypes: China: 3 ♀♀, same label data as holotype (NSMT); 1 ♂, 1 ♀, labeled 'Tropical Rainforest (Tropical Botanical Garden) {热带植物园}, Menglun {孟仑}, Mengla County {勐腊县} / (Xishuangbanna), S. Yunnan, China, Oct. 29th, 1992, Coll. Y. Watanabe.' (SNUC). Each paratype bears a type label as: 'PARATYPE {yellow} ♀ {or ♂}, Horniella aculeata sp. n., det. Yin & Li, 2015, NSMT {or SNUC}'.

Description.

Male (Fig. 1A). Length 2.95-3.0 mm. Head slightly wider than long, HL 0.54-0.58 mm, HW 0.61-0.62 mm; anterolateral genal projections (Fig. 2C) distinct, anterior margins evenly concave; median sulcus between antennal tubercles short and deep; scapes (Fig. 2B) acutely expanded at basolateral margins; clubs (Fig. 2A) loosely formed by apical three moderately enlarged antennomeres; head venter with pair of short, strongly curved lateral spines (Fig. 2D). Maxillary palpomeres II stout, broadened at middle. Each eye composed of about 30 facets. Pronotum slightly longer than wide, PL 0.63-0.64 mm, PW 0. 59-0. 61 mm. Elytra wider than long, EL 0.82-0.85 mm, EW 1.23-1.25 mm; discal striae reaching apical 2/3 of elytral length. Protrochanters and profemora (Fig. 2E) each with one distinct ventral spine, protibiae (Fig. 2F) with mesal margins strongly arcuate at apical half, with large sharp spine at mesal margin near middle; mesotrochanters (Fig. 2G) each with one short, blunt ventral protuberance, mesofemora simple, mesotibiae (Fig. 2H) simple; tarsomeres II normal, not extending to beneath tarsomeres III. Abdomen large, AL 0.94-0.95 mm, AW 1.19-1.26 mm; tergite IV (first visible tergite) with median carina extending to half tergal length or slightly more, lateral discal carinae short; tergite V lacking median carina. Sternite IX (Fig. 2I) nearly oval, with well-sclerotized apical half and membranous basal half. AeL 0.62 mm; aedeagus (Fig. 2 J–L) with slightly asymmetric median lobe slightly curved rightwards in dorso-ventral view; endophallus composed of one conspicuously long, partly membranous, and twisted sclerite with pointed, curved apex.

Female. Similar to male in general appearance; scapes not expanded at basolateral margins; each eye composed of about 25 facets; profemora each with two subequal ventral spines near base, protibiae lacking spine, not strongly arcuate at apical half; mesotrochanters lacking ventral spine. BL 2.81-2.94 mm, HL 0.65-0.69 mm, HW 0.57-0.58 mm, PL 0.62-0.63 mm, PW 0.59-0.61 mm, EL 0.70-0.74 mm, EW 1.12-1.16, AL 0.84-0.88 mm, AW 1.22-1.23 mm. Genital complex (Fig. 5A) 0.36 mm wide, with slightly sclerotized, transverse apical portion, and with membranous, elongate basal portion.

Differential diagnosis.

The new species is placed as a member of the Horniella burckhardti group (for diagnoses of species-groups refer to Yin and Li 2014). Males of Horniella aculeata have the aedeagal endophallus composed of one elongate sclerite, similar to that of Horniella hongkongensis Yin & Li. The two species can be readily separated by 1) the more distinct and acute protuberance on the mesal margins of the scapes, 2) the oblique ventral spine at base of the profemora, and 3) the presence of a large, sharp spine on the mesal margins of the protibiae in Horniella aculeata . In Horniella , the presence of a spine on the mesal margin of the protibiae only occurs in Horniella simplaria Yin & Li which belongs to the Horniella hirtella group, otherwise the two species are easily separable from each other.

Distribution.

Southwestern China: Yunnan.

Etymology.

The specific epithet refers to the acute spine on the protibia.