New Species, New Synonymy, and Additional Records ofSyndicusMotschulsky (Coleoptera: Staphylinidae: Scydmaeninae) Author Yin, Zi-Wei Author Zhou, De-Yao text The Coleopterists Bulletin 2016 2016-12-31 70 4 871 879 http://dx.doi.org/10.1649/0010-065x-70.4.871 journal article 10.1649/0010-065X-70.4.871 5340480 Syndicus ( Syndicus ) qiong Yin and Zhou , new species ( Figs. 1A , 2 , 4A–B ) Type Material. Holotype ♂ : ‘ China : Hainan , Ledong Hsien (), Jianfengling (), Mingfenggu (), rotten wood, sifted, 18°44′ 43.09″N , 108°52′32.16″E , 1012 m , 25.i.2015 , Peng & Tu leg. / HOLOTYPE (red), ♂ , Syndicus qiong sp. n. , det. Yin & Zhou , 2016’ ( SNUC ) . Diagnosis. This new species can be readily separated from all other Syndicus species of the nominotypical subgenus by the presence of a marginal impression on the elytral flank, rounded elytral apices, broadened apex of the aedeagal paramere, and unique structures of the aedeagal endophallus. Description. Male. BL = 2.65 mm ; body ( Fig. 1A ) moderately convex, reddish brown, legs and palpi slightly lighter. Head broadest at large, finely faceted, and moderately convex eyes, HL = 0.40 mm , HW = 0.60 mm ; tempora in strictly dorsal view rounded; vertex transverse, regularly convex; antennal tubercles slightly prominent; clypeus not modified, with anterior margin nearly straight. Head sparsely and finely punctate; setae sparse, moderately long. Antenna ( Fig. 2A ) slightly longer than 0.6X BL, antennomere II small, other antennomeres subequal in width throughout, AnL = 1.71 mm , relative lengths of antennomeres = 1.9: 1.0: 1.2: 1.7: 2.0: 2.2: 2.2: 2.4: 2.5: 2.6: 1.0. Pronotum elongate with regularly convex, trapezoidal disc, broadest near anterior fourth; PL = 0.83 mm , PWb = 0.51 mm , PWm = 0.65 mm ; sides strongly narrowing posteriorly and strongly constricted near posterior third; posterior collar short, separated from disc by transverse row of 4 distinct dorsal pits; punctation of disc similar to that on head; setae long, suberect, moderately dense. Elytra in lateral view slightly more convex than pronotum, broadest at middle and strongly narrowing toward apices; EL = 1.42 mm , EW = 0.93 mm , EI = 1.52; humeral calli distinct, protruding anteriorly; flank of each elytron with shallow but broad lateral impression at posterior 2/3 ( Fig. 4A ); apices of elytra rounded ( Fig. 4B ); disc coarsely punctate; setae similar to those on pronotum, those on lateral impressions much shorter and denser. Legs with dorsal femoral groove broad and deep, extending from base toward apex of femoral clava; metafemur with ventral margin of clavate part smoothly rounded ( Fig. 2H ). Aedeagus ( Fig. 2B–D ) relatively stout, AeL = 0.48 mm ; endophallus ( Fig. 2E–F ) with complicated system of strongly to weakly sclerotized structures; parameres ( Fig. 2G ) each with broadened apex in lateral view, distinctly exceeding apex of median lobe, without setae. Fig. 1. Syndicus species , dorsal habitus. A) S . qiong , B) S . philippinus . Fig. 2. Syndicus qiong , male. A) Right antenna, B) Aedeagus, dorsal view, C) Aedeagus, lateral view, D) Aedeagus, ventral view, E and F) Endophallus, dorsal view, G) Paramere, lateral view, H) Metafemur, lateral view. Female. Unknown. Comparative Notes. This new species is closest to Syndicus ( s . str .) vietnamensis Jałoszyński, 2004 from Hoa Binh Province , Vietnam , by sharing a similar body size and proportions of the body parts, presence of a marginal impression on the elytral flank, and a similar apex of the aedeagal endophallus. However, S . qiong can be clearly separated by the more elongate pronotum and elytra, much less distinct elytral marginal impression, rounded elytral apices, smoothly rounded ventral margin of the clavate part of the metafemur, broadened apex of the paramere (in lateral view) which is much longer than the apex of the median lobe, and different structure of the endophallus. In S . vietnamensis , the pronotum and elytra are stouter, the elytral marginal impressions are more distinct and deeper, the apices of the elytra are each pointed (sometimes less so, but never as round as those in S . qiong ), the clavate part of the metafemur has a strongly expanded ventral margin at the base, and the parameres are of the same width from the middle toward the apex and only slightly exceed the apex of the median lobe. Bionomics. The single male was collected from a fallen decomposing log in an evergreen broadleaf forest at the Mingfeng Valley. Distribution. China : Hainan . Etymology. The Chinese character ‘Qiong ()’ is a short term for Hainan , from where the holotype was collected.