Eight new species and additional records of the Pselaphodes complex from Laos and Vietnam, with a key to known species (Coleoptera: Staphylinidae: Pselaphinae) Author Yin, Zi-Wei Laboratory of Systematic Entomology, College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Xuhui District, Shanghai 200234, China pselaphinae@gmail.com Author Li, Ning Laboratory of Systematic Entomology, College of Life Sciences, Shanghai Normal University, 100 Guilin Road, Xuhui District, Shanghai 200234, China. text Acta Entomologica Musei Nationalis Pragae 2021 Acta. Ent. Mus. Natl. Pragae 2021-02-18 61 1 35 53 http://dx.doi.org/10.37520/aemnp.2021.002 journal article 55892 10.37520/aemnp.2021.002 f5f6ab5f-d650-4e1f-b6e3-c21928723245 1804-6487 5037464 0AEECD1F-1C71-4636-89A7-DA31D2DB73D6 Labomimus cucphuong sp. nov. ( Figs 1B , 3 ) Type material ( 1 specimen ). HOLOTYPE : VIETNAM : NINHBÌNH : ♂ , ‘VIETNAM N, 100 EM s from Hanoi CUC-PHUONG nat. Park , 02.- 12.5.1991 , leg. E. Jendek’ ( MHNG ) . Diagnosis. Male body length 2.84 mm . Antennomere 9 with round, deep ventral concavity in apical half; antennomere 10 strongly constricted at base and forming nodule-like stem, broadly impressed for most area of ventral side. Horn-like metaventral processes in lateral view slightly broaden at apices. Protrochanter with blunt ventral projection, protibia with small tubercle at apex; mesotrochanter with small triangular protuberance. Median lobe of aedeagus almost symmetric dorsoventrally; parameres thin and elongate; endophallus with seven sclerites and one structure. Female unknown. Description. Male ( Fig. 1B ). Body length 2.84 mm . Head winder than long, HL 0.48 mm , HW 0.56 mm ; eyes prominent, each composed of about 43 facets. Antennomeres 3–8 gradually becoming shorter, antennomeres 9–11 ( Fig. 3A ) forming distinct club; antennomere 9 with round, deep ventral concavity in apical half, antennomere 10 strongly constricted near base and forming nodule-like stem, most part of ventral surface broadly impressed, antennomere 11 much shorter than 10, truncate at base and with round apex. Pronotum ( Fig. 3B ) slightly longer than wide, PL 0.56 mm , PW 0.50 mm , narrowed anteriorly at apical 2/5. Elytra broader than long, EL 0.74 mm , EW 1.05 mm . Horn-like metaventral processes ( Fig. 3C ) in lateral view slightly expand at apices. Protrochanter ( Fig. 3D ) with blunt projection; profemur angularly expanded at middle; protibia ( Fig. 3E ) with small tubercle at apex; mesotrochanter ( Fig. 3F ) with short triangle protuberance; mesofemur ( Fig. 3F ), metatrochanter and metafemur ( Fig. 3G ) simple. Abdomen broad at base and narrowed apically, AL 0.96 mm , AW 1.07 mm . Aedeagus ( Figs 3H–J ) 0.51 mm long; median lobe almost symmetric dorsoventrally, in lateral view curved and narrowed at apex; each paramere with two preapical setae; endophallus composed of seven sclerites and one membranous structure. Female . Unknown. Comparative notes. This species can be readily recognized and distinguished from all other members of the genus by uniquely modified male antennal club. Etymology. The new species is named after the type locality, Cúc PhƯƠng National Park. The species name is a noun in apposition. Distribution. Vietnam: Ninh Bình.