(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}’.

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. 2J–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.

Figure 1. 

Male habitus of Horniella species. A H. aculeata B H. jinggangshana. Scales: 1.0 mm.

Figure 2. 

Male diagnostic features of Horniella aculeata A antennal club B scape C right half of the 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, in dorsal view K same, in lateral view L same, in ventral view. Scales: all = 0.3 mm, except B, I = 0.1 mm.

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.

The new species is placed as a member of the H. 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 H. 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 H. aculeata. In Horniella, the presence of a spine on the mesal margin of the protibiae only occurs in H. simplaria Yin & Li which belongs to the H. hirtella group, otherwise the two species are easily separable from each other.

Southwestern China: Yunnan.

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

(1 ♂, 2 ♀♀). Holotype: China: ♂, labeled ‘China: W. Jiangxi, Ji’an City, Jinggang Shan N. R. {井冈山自然保护区}, Shuikou {水口}, 26°32'42"N, 114°06'03"E, mixed leaf litter, sifted, 790–900 m, 30.vii.2014, J.Y. Hu / HOLOTYPE {red} ♂, Horniella jinggangshana sp. n., det. Yin & Li, 2015, SNUC’ (SNUC). Paratypes: China: 2 ♀♀, same label data as holotype (SNUC). Each paratype bears a following label: ‘PARATYPE {yellow} ♀, Horniella jinggangshana sp. n., det. Yin & Li, 2015, SNUC’.

Male (Fig. 1B). Length 3.67 mm. Head as long wide, HL 0.75 mm, HW 0.75 mm; anterolateral genal projections (Fig. 3C) distinct, anterior margins slightly concave; median sulcus between antennal tubercles short and moderately deep; scapes (Fig. 3B) angularly expanded at basolateral margins; clubs (Fig. 3A) loosely formed by apical three moderately enlarged antennomeres; venter with pair of markedly long, curved lateral spines (Fig. 3D). Maxillary palpomeres II stout, broadened at middle. Each eye composed of about 35 facets. Pronotum slightly longer than wide, PL 0.76 mm, PW 0.72 mm. Elytra wider than long, EL 0.94 mm, EW 1.46 mm; discal striae reaching more than apical 2/3 of elytral length. Protrochanters and profemora (Fig. 3E) each with one distinct ventral spine, protibiae (Fig. 3F) each with short apical protuberance; mesotrochanters (Fig. 3G) each with one big ventral spine, mesofemora simple, mesotibiae (Fig. 3H) with small preapical denticles and short apical projection; tarsomeres II normal, not extending to beneath tarsomeres III. Abdomen large, AL 1.22 mm, AW 1.41 mm; tergite IV (first visible tergite) with short median carina, lacking lateral discal carinae; tergite V lacking median carina. Sternite IX (Fig. 3I) nearly oval, with well-sclerotized apical half and membranous basal half. AeL 0.82 mm; aedeagus (Fig. 3J–L) with left half of median lobe greatly protruding in dorso-ventral view; endophallus composed of three long, curved sclerites.

Figure 3. 

Male diagnostic features of Horniella jinggangshana A antennal club B scape C right half of the 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, in dorsal view K same, in lateral view L same, in ventral view. Scales: all = 0.3 mm, except B, I = 0.1 mm.

Female. Similar to male in general appearance; scapes not expanded at basolateral margins; each eye composed of about 35 facets; profemora each with two subequal ventral spines near base, protibiae lacking preapical protuberance; mesotrochanters lacking ventral spine, mesotibiae lacking apical projection; tergite VII with posterior margin protruding at middle. BL 3.53–3.58 mm, HL 0.65–0.69 mm, HW 0.66–0.72 mm, PL 0.66–0.70 mm, PW 0.65–0.66 mm, EL 0.92–0.93 mm, EW 1.30–1.37, AL 1.26–1.30 mm, AW 1.33–1.34 mm. Genital complex (Fig. 5B–C) 0.43 mm wide, with broad apical portion, and coil-shaped basal portion.

The new species is placed as a member of the H. centralis group. Its closest congener is probably H. falcis Yin & Li, which is known from a single female. The females of these two species share a similar habitus, the protruding posterior margin of tergite VII, and a similar form of the genital complex. They can be tentatively separated by the less protruding posterior margin of tergite VII, the broader genital complex in dorsal-ventral view in Horniella jinggangshana, and their distributions (straight line distance of separation measures ca. 710 km). The males of Horniella jinggangshana can be readily separated from all other congeners by the unique form of the aedeagus and structure of the endophallus.

Eastern China: Jiangxi.

The new species is named after its type locality, the Jinggang Shan Nature Reserve.

1 ♂, 1 ♀, labeled ‘Mt. Jizu Shan {鸡足山, ca. 25°58'N, 100°23'E } (2130 m), Binchuan {宾川县}, NW Yunnan, China, 25.X.1995, Coll. Y. Watanabe & Xiao N. / Horniella nakhi Yin & Li, 2014, det. Z.W. Yin, 2015’ (NSMT).

This species was known from one male and two females collected in Naxi Autonomous County. The present record extends its distribution to the Jizu Mountain, ca. 90 km south from the type locality.

The population from Jizu Mountain exhibits a stouter aedeagal form and different structure of the endophallus (Fig. 5D–E). These are attributed to intraspecific variation because all other male diagnostic features, e.g. the strongly projecting apical portion of the protibiae, seem quite stable.

3 ♀♀, labeled ‘Carin, Asciuii Chebà, 1200–1300 m, L. Fea. III-IV.{18}88. / Museo, Civico, di Genova; 1 ♀, same data, except for ‘I - 88’ (MSNG). Each specimen bears a following label: ‘cf. Horniella sup. 1., Horniella sp. 1, det. Z.W. Yin, 2015’.

Female (Fig. 4A). BL 3.70–3.78 mm, HL 0.80–0.81 mm, HW 0.72–0.73 mm, PL 0.76–0.78 mm, PW 0.74–0.75 mm, EL 1.0–1.02 mm, EW 1.48–1.52 mm, AL 1.11–1.20 mm, AW 1.59–1.60 mm. Each eye composed of about 38 facets. Width of genital complex 0.37 mm.

Figure 4. 

Male habitus of Horniella species. A Horniella sp. 1 B Horniella sp. 2 C Horniella sp. 3. Scales: 1.0 mm.

Eastern Myanmar: Kayah State.

The large body size combined with the unique setation on tergite V (Fig. 5F) clearly indicates a new species. The female genital complex (Fig. 5G) is here illustrated for reference to future study.

Figure 5. 

Details of Horniella species (A Horniella aculeata B–C Horniella jinggangshana D–E Horniella nakhi F–G Horniella sp. 1 H Horniella sp. 2 I Horniella sp. 3). A, B, G, H, I female genital complex, in dorsal view C same, in lateral view D aedeagus, in dorsal view E same, in lateral view F abdomen, in dorsal view. Scales: all = 0.2 mm, except F = 0.5 mm.

2 ♀♀, labeled ‘Carin, Asciuii Chebà, 900–1100 m, L. Fea. V XII-{18}88. / Museo, Civico, di Genova / cf. Horniella sup. 1., Horniella sp. 2, det. Z.W. Yin, 2015’ (MSNG).

Female (Fig. 4B). BL 3.09 mm, HL 0.61–0.64 mm, HW 0.57–0.58 mm, PL 0.66–0.67 mm, PW 0.57–0.58 mm, EL 0.79–0.80 mm, EW 1.19–1.20 mm, AL 1.00–1.01 mm, AW 1.23–1.25 mm. Each eye composed of about 40 facets. Width of genital complex 0.33 mm.

Eastern Myanmar: Kayah State.

This material represents the first record of the Horniella hirtella group in Myanmar. The form of the genital complex (Fig. 5H) is highly similar to that of Horniella philippina Yin & Li (Yin and Li 2014: fig. 49F), but the Myanmar population probably represents a different species insomuch as its distribution is considered, as well as the presence of a much longer median carina on tergite IV.

1 ♀, labeled ‘Guibeishan (450 m), (Tull.), Yaoshan Xiang, Libo Xian / [Guizhou, CHINA], 中国贵州省荔波县瑶山乡, 11.ix.1997, T. Kishimoto / cf. Horniella sup. 1., Horniella sp. 3, det. Z.W. Yin, 2015’ (NSMT).

Female (Fig. 4C). BL 3.15 mm, HL 0.74 mm, HW 0.60 mm, PL 0.66 mm, PW 0.64 mm, EL 0.81 mm, EW 1.31 mm, AL 0.94 mm, AW 1.32 mm. Each eye composed of about 22 facets. Width of genital complex 0.46 mm.

Southwestern China: Guizhou.

The unique form of the genital complex and distribution of this female indicate a different species. Illustration of its genital complex (Fig. 5I) is provided for future comparison.