Trapeziderus, MotschulskY, 1860

Park, Joon-Yong & Ahn, Kee-Jeong, 2021, Description of a New Species of Trapeziderus Motschulsky (Coleoptera: Staphylinidae: Staphylininae) in Korea, The Coleopterists Bulletin 75 (2), pp. 334-338 : 334-338

Genus TRAPEZIDERUS MotschulskY , 1860

Trapeziderus Motschulsky 1860: 77 (species includ- ed: T. bicolor ); Motschulsky 1870: 49 [junior synonym of Trapezinotus (unjustified)]; Fauvel 1895: 266 (junior synonym of Belonuchus ); Chani-Posse et al. 2018: 33 (status resurrection).

Type species: Trapeziderus bicolor Motschulsky , fixed by monotypy.

Diagnosis. Trapeziderus can be recognized by the following combination of characters: head without infraorbital ridge; maxillary palpus long, with palpomere 4 rod-like and longer than palpomere 3; usually with crescent-shaped temporal carina; superior line of pronotal hypomeron bent ventrad at about middle of pronotum so that lateral puncture of pronotum, bearing long seta, separated from it by a distance of at least three times diameter of puncture; mesocoxal cavities widely separated; front tarsomeres 1–4 moderately dilated, with some adhesive and apically oval-shaped pale setae ventrally; middle tibia with very long and thin seta mesolaterally; abdomen with first three or four visible tergites bearing two basal lines; sternite III with basal transverse carina straight to arcuate on medial region; male sternite VIII variably emarginate medio-apically; paramere of aedeagus usually with sensory peg setae (Chani-Posse et al. 2018; Li and Zhou 2010).

TRAPEZIDERUS koREAnUS Park and Ahn , new species zoobank.org/ urn:lsid:zoobank.org:act:6822DD94-59E7-4302-9A73-0231764DC7D4 ( Figs. 1–15 )

TYpe Material. HolotYpe, ♂, labeled as follows: “ KOREA: Chungnam Prov., Daejeon-si, Dong-gu, Secheon-dong , Mt. Sikjangsan , N36°19′32.23″ E127°29′1.70″ 151 m, 21 V 2019, JY Park, under bark; HOLOTYPE Trapeziderus koreanus Park and Ahn 2020 ”. Deposited in CNUIC . ParatYpes, 5 exx. ( CNUIC): 1♂ 4♀, same data as holotype .

Other Material Examined. 4 exx. ( CNUIC) : 1♂, “ KOREA: Chungnam Prov., Daejeon-si, Yuseong-gu, Gung-dong , Chungnam National University , 27 V-2 VI 2014, GR Hong, Lindgren funnel trap ” ; 1♀, same data as holotype except “ 5 IV 2019 ” ; 1♂, same data as holotype ; 1♂, “ KOREA: Gangwon Prov., Wonju-si, Socho-myeon, Mt. Chiaksan , N37°23′44.85″ E128°03′05.89″ 393 m, 18 IX 2019, JS Lee, JY Park, under bark” .

Description. Habitus as in Fig. 1 , body length 8.7–10.8 mm. Body moderately flattened dorso-ventrally. Head and pronotum nearly black, sometimes with strongly golden luster; elytra and scutellar shield nearly black; abdomen nearly black; antennomeres 1–9 nearly black, antennomeres 10–11 reddish-brown and antennomere 11 paler at apex; mandibles nearly black, maxillary and labial palpi and legs reddish-brown. Head: Rectangular with rounded hind angles, about 0.58– 0.79 times as long as wide, about 1.10–1.15 times as wide as pronotum; surface glossy with coarse punctures, conspicuous microsculpture of transverse waves present; frons with four punctures arranged in a rectangular shape; eye moderate in size, about 0.63–0.80 times as short as temple; temporal carina present; vertex with large impunctate area; gular sutures converged at about half; antennae moderately long, antennomere 1 almost as long as 2–3 combined, 2 distinctly shorter than 3, 4 longer than wide, 5 almost as long as wide, 6–10 wider than long, 11 distinctly longer than wide, obliquely truncate. Mouthparts: Labrum transverse, anterior margin emarginate, lateral margin rounded; mandibles almost symmetrical, each with one simple tooth; prostheca long and slender with cilia along entire length, cilia gradually shortening apicad; maxillary palpus elongate, palpomere 4 rod-like, longer and narrower than 3; labial palpus elongate, palpomere 3 fusiform, longer and only slightly narrower than 2; ligula not divided. Thorax: Pronotum distinctly narrowed posteriad, almost as long as wide, widest at anterior third; surface glossy with similar microsculpture as on head; disc with 1 pair of dorsal rows including antero-marginal setae ( Fig. 2 ) each with 7–9 punctures, anterior third of sublateral region excluding antero-marginal setae ( Fig. 3 ) each with 2–4 punctures; hypomeron visible in lateral view; elytron slightly widened posteriad, almost as long as wide, with fine and dense punctures, postero-outer margin rounded, posterior margin emarginate; mesoventrite with transverse crenate carina; mesoventral process extended less than half of mesocoxal cavity, rounded at apex; middle and hind tibia with very long and slender seta mesolaterally. Abdomen: Slightly narrowed posteriad, closely and finely punctate; surface between punctures with exceedingly fine and dense microsculpture of transverse striae; first 3 visible abdominal tergites with 2 basal lines. Male: Front tarsomeres 1–4 slightly dilated and each bearing some modified pale setae ventrally; tergite VIII subtruncate apically ( Fig. 4 ); sternite VIII very slightly emarginate medio-apically ( Fig. 5 ); lateral tergal sclerites IX simple, moderately setose apically ( Fig. 6 ); sternite IX asymmetrical at basal portion, moderately emarginate medio-apically, each side of emargination with one long apical seta and numerous subapical setae ( Fig. 7 ); tergite X simple, triangular, subrounded apically, with numerous apical setae ( Fig. 8 ); median lobe of aedeagus subrounded apically ( Fig. 9 ); in lateral view, median lobe distinctly widened anteriad, with a very small tooth subapically ( Fig. 10 ); paramere distinctly shorter and narrower than median lobe, subrounded at apex, adjacent to median lobe with 6–11 round peg setae arranged along latero-apical margins ( Fig. 11 ). Female: Front tarsomeres 1–4 slightly dilated and each bearing some modified 336 pale setae ventrally; tergite VIII similar to that of and Zhou 2010) but the other East Asian species do male ( Fig. 12 ); sternite VIII subrounded apically, not possess these characters. The new species can without medio-apical emargination ( Fig. 13 ); lat- be distinguished from T. imitator by the rederal tergal sclerites IX similar to that of male; gono- dish-brown antennomere 10, the chaetotaxy of the coxites moderately developed, each with minute pronotum (5 or 6 large punctures in each lateral stylus bearing one long seta ( Fig. 14 ); tergite X portion on pronotum in T. imitator but more than 6 similar to that of male ( Fig. 15 ). in T. koreanus ), the incomplete basal line of male

Distribution. Korea (South). sternite VIII, and the shape and structure of the ae-

Remarks. The new species is similar to T. imita- deagus (median lobe and paramere narrower in T. tor in having black elytra and a temporal carina (Li koreanus compared to T. imitator ).

338 ACKNOWLEDGMENTS Li, L., and H.-Z. Zhou. 2010. Revision of the Chinese species of the genus Belonuchus Nordmann (Co-

We thank M. Geiser (BMNH, London) for pro- leoptera: Staphylinidae : Philonthina ). Journal of Natural History 44: 2149–2177.

viding valuable specimens. The comments and Li, L., and H.-Z. Zhou. 2011. Revision and phylogenetic

suggestions by two anonymous reviewers signifi- assessment of the rove beetle genus Pseudohespe-

cantly improved the manuscript. This work rus Hayashi, with broad reference to the subtribe was supported by a grant from the National Philonthina ( Coleoptera : Staphylinidae : Staphyli-

Institute of Biological Resources (NIBR), funded nini). Zoological Journal of the Linnean Society 163: 679–722.

by the Ministry of Environment ( MOE) of Motschulsky , V. 1860. Entomologie spéciale. Insectes the Republic of Korea ( NIBR202028201 and des Indes orientales, et de contrées analogues.

NIBR202002205). Etudes Entomologiques 8: 25–118.

Motschulsky, V. 1870. Genres et espéces d’insectes, publiés dans différents ouvrages. Horae Societatis

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Figures

Figs. 1–3. Trapeziderus koreanus, new species. 1) Habitus, holotype, male, 8.9 mm; 2) Dorsal row (dotted line) on pronotum; 3) Anterior third of sublateral region (dotted line) on pronotum.

Figs. 4–15. Trapeziderus koreanus, new species. Male: 4) Tergite VIII, dorsal view; 5) Sternite VIII, ventral view; 6) Lateral tergal sclerites IX, dorsal view; 7) Sternite IX, ventral view; 8) Tergite X, dorsal view; 9) Aedeagus, ventral view; 10) Aedeagus, lateral view; 11) Paramere, dorsal view. Female: 12) Tergite VIII, dorsal view; 13) Sternite VIII, ventral view; 14) Gonocoxites, ventral view; 15) Tergite X; dorsal view. Scale bar = 0.1 mm.