Syndicus (Semisyndicus) wangjisheni sp. nov. (Fig. 2) Type material (1 ex.). Holotype: CHINA: Ƌ, labeled ‘ Yunnan, Lincang City, Tangli Mountian, 24°02'23''N, 99°13'38''E, 2489 m, 2020.ii.13, rotten Wood, sifted, Ji-Shen Wang leg., ủfflfiȏȑḿṫḗflŝḭffi’ (SNUC). Diagnosis. Male. Body length approximately 3.0 mm, pronotal length/width approximately 1.20, elytral length/ width approximately 1.5; endophallus of aedeagus comprises a unique C-shaped (in lateral view) sclerite, sub-pentagonal apical plate symmetrical, narrowing from subbasal region toward apex. Description. Male. Body (Fig. 2A) length (combined length of head, pronotum and elytra) 3.03 mm. Body slender, moderately convex, dark reddish-brown; legs and palpi slightly paler. Head slightly wider than long, length from anterior margin of clypeus to head base 0.61 mm, width across eyes 0.63 mm. Eyes shorter than laterally rounded tempora, moderately prominent; vertex comparatively long and flat; frons moderately concave; supraantennal tubercles slightly raised, confluent with frons and vertex. Punctation of frons and vertex composed of sharply marked punctures distributed densely and slightly unevenly; setation relatively short, composed of thin, suberect setae. Antennae (Fig. 2B) relatively short, length 1.28 mm. Pronotum relatively slender and elongate, widest at anterior 1/3, length along midline 0.86 mm, maximum width 0.72 mm. Both Anterior and lateral margins rounded. Lateral constriction distinct, located at posterior third; lateral groove absent; posterior collar relatively long, demarcated from disc by transverse row of four large and deep antebasal pits; with two additional lateral pits slightly smaller than antebasal ones; area between inner pair of basal pits raised and forming indistinctly delimited median longitudinal carina; base of pronotum slightly curved. Punctation of disc much more distinct than that of head, composed of much larger, unevenly distributed and moderately dense punctures of various diameters, largest punctures located in central part of disc; posterior constriction behind antebasal pits devoid of punctures. Setation of pronotum moderately dense, relatively short, suberect. Elytra long, elliptical, widest anterior to middle, length along suture 1.61 mm, maximum width 1.08 mm, length/width 1.49. Humeri well-marked, delimited from adsutural area by broad and shallow impression; extremely narrow adsutural area near base moderately raised; median circumsutural area on elytra slightly impressed near anterior third. Punctation of elytra distinct, composed of punctures smaller than those of pronotum, punctures moderately dense and evenly distributed, largest on median impression and reducing in diameters and depth toward lateral and posterior margins; setation slightly lighter in color than that on pronotum, moderately dense, setae relatively short, slightly suberect. Aedeagus (Fig. 2C, D) elongate, 0.72 mm long; parameres (Fig. 2G) slender with apices slightly exceeding emarginate apex of median lobe, each paramere with several short preapical setae; endophallus (Fig. 2E, F) almost symmetrical, with sclerotized central complex located near base of median lobe, and sub-pentagonal apical plate located near apex of median lobe; one strongly curved sclerite extends from the base of central complex, which is curved to form C-shaped open loop. Female. Unknown. Comments. Since Jałoszyński (2004) reported the first member of Syndicus from China, seven more species have been described or newly recorded from the country (Jałoszyński 2008, 2011; Yin et al. 2014; Yin & Li 2015; Yin & Zhou 2016; Zhou & Yin 2017). The new species described here is most similar to S. (Semisyndicus) long Zhou & Yin, also distributed in Yunnan, in sharing the distinct C-shaped structure of the endophallus, which is absent in the other Semisyndicus species (Zhou & Yin 2017). These two species can be separated only by the different structure of the endophallus. In S. wangjisheni sp. nov., the sub-pentagonal apical plate is symmetrical and narrowing from subbasal region toward apex (Fig. 2F), while it is slightly asymmetrical and of a different shape in S. long (Zhou & Yin 2017: fig. 4E). Moreover, the C-shaped sclerite of S. wangjisheni sp. nov. is more strongly curved at the apex, and the structure of the basal sclerites of the endophallus is less complicated. Distribution. China: Yunnan. Etymology. The new species is named after Ji-Shen Wang, a specialist in Mecoptera systematics and collector of the type specimen.

Published as part of Li, Qi-Qi & Yin, Zi-Wei, 2021, Four new species of Scydmaeninae and Pselaphinae (Coleoptera: Staphylinidae) from Yunnan, China, pp. 114-122 in Zootaxa 4920 (1) on pages 116-118, DOI: 10.11646/zootaxa.4920.1.5, http://zenodo.org/record/4471693