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 Pselaphodes parapectinatus sp. nov. ( Figs 10B , 12 ) Type material ( 11 specimens ). HOLOTYPE : VIETNAM : LÀO CAI: ♂ , ‘VIETNAM N, 22′20′N, 103′50′E, SAPA ( Lao Cai ) 25.5- 10.6.1991 , leg. E. Jendek’ ( MHNG ) . PARATYPES : VIETNAM : LÀO CAI : 9 ♂♂ , same label data as for holotype ( MHNG , SNUC ); 1 ♂ , ‘C N-Vietnam], 23.v.1998 / Mt. Phang Si Pang (1,840, beating), Lao Cai Prov .’ ( MHNG ) . Diagnosis. Male length 3.23–3.28 mm . Antennomeres 9–11 greatly elongate and forming distinct club, antennomere 9 with large disc-like process near apex. Horn-like metaventral processes short and apically blunt. Profemur with ventral spine before middle expansion; protibia strongly curved, with small middle spine and large apical projection. Median lobe of aedeagus almost symmetric dorso-ventrally; parameres long and broad; endophallus composed of broad, plate-like structure and elongate sclerite. Female unknow. Description. Male ( Fig. 10B ). Body length 3.23–3.28 mm . Head slightly longer than wide, HL 0.65–0.70 mm , HW 0.63 mm ; eyes prominent, each composed of about 42 facets. Antennomeres 2–8 of similar form, each slightly longer than wide, antennomeres 9–11 ( Fig. 12A ) each much longer than wide, antennomere 9 with distinct disclike process near apex, antennomere 10 subcylindrical, slightly broadened from base toward apex, antennomere 11 sub-oval, narrowing apically. Pronotum ( Fig. 12B ) approximately as long as wide, PL 0.63–0.65 mm , PW 0.60–0.63 mm , sides roundly narrowing apically at apical 2/5. Elytra slightly longer than wide, EL 0.93–0.95 mm , EW 0.90 mm . Horn-like metaventral processes ( Fig. 12C ) in lateral view roundly triangular, short and blunt at apices. Profemur ( Fig. 12D ) with triangular spine at basal 1/3, angularly expanded at middle; protibia ( Fig. 12E ) strongly curved in apical half, with small spine near middle and large apical projection; mesotrochanter, mesofemur ( Fig. 12F ), metatrochanter and metafemur ( Fig. 12G ) simple. Abdomen broad at base and narrowed posteriorly, AL 0.90–0.95 mm , AW 1.08–1.15 mm ; tergite 1 (IV) longest, more than twice as long as tergite V; sternite 7 (IX) ( Fig. 12H ) hemi-membranous, suboval.Aedeagus ( Figs 12I –E ) 0.76 mm long; median lobe nearly symmetric dorso-ventrally; parameres each elongate and broad, with enlarged, round apices; endophallus comprising one plate-like sclerite with many small spines at apex, and one elongate, curved sclerite. Female . Unknown. Comparative notes. The new species is most similar to P. pectinatus Yin, Li & Zhao, 2011 from Hainan, southern China, by sharing similar position and structure of the leg modifications, and short horn-like metaventral processes of the male. These two species differ in the presence of a large disc-like process on antennomere 9 (process lacking in P. pectinatus ), a much shorter and differently shaped apical projection of protibia, each paramere of aedeagus lacking the apical setae and roundly broadened at the apex (each paramere with many thick apical and preapical setae, and rounded but not broadened at the apex in P. pectinatus ), and different structure of the endophallic sclerites of P . parapectinatus sp. nov. Etymology. The new specific name reflects the morphological similarity between the new species and P. pectinatus . The name consists of the Greek prefix pará - (beside; next to, near, from) and the Latin adjective pectinatus (- a , - um ; meaning combed). Distribution. Vietnam: Lào Cai.