Revision of the Oriental genus Horniella Raffray (Coleoptera, Staphylinidae, Pselaphinae) – Supplementum 1

Abstract Two new species of the genus Horniella Raffray are described from China: Horniella aculeata sp. n. (Yunnan Province) and Horniella jinggangshana sp. n. (Jiangxi Province). Horniella nakhi Yin & Li is recorded from a new locality. Three potentially new species from Myanmar and China, each represented by female specimen(s) only, are left unnamed. Their collecting data are given, and the genital complex figured for future comparison.


Introduction
Since the publication of our revision of the genus Horniella Raffray (Yin and Li 2014), we have had the opportunity to examine additional material collected in China and Myanmar. A study of this material revealed two new species, a new locality for Horniella nakhi Yin & Li, and the first record of the genus from Myanmar. The material also includes three possibly different species represented only by females that are kept unnamed until associated males become available in the future.

Material and methods
The methods, terminology, and abbreviations applied are the same as in Yin and Li 2014. Authors' supplementary notes are included in brackets.

Horniella aculeata
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.   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 (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.
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 Differential diagnosis. 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.
Distribution. Eastern China: Jiangxi. Etymology. The new species is named after its type locality, the Jinggang Shan Nature Reserve. Distribution. 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.

Horniella nakhi Yin & Li
Comments. 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.

Distribution. Eastern Myanmar: Kayah State.
Comments. 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) 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.  Measurements. 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.
Distribution. Southwestern China: Guizhou. Comments. 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.