Zethopsus Reitter, 1880

Byeon, Ui-Joung & Park, Jong-Seok, 2023, Review of the Korean Species of the Tribe Bythinoplectini Schaufuss, 1890 (Coleoptera: Staphylinidae: Pselaphinae: Euplectitae), The Coleopterists Bulletin 77 (3), pp. 413-427 : 419-421

Genus Zethopsus Reitter, 1880

Zethopsus Reitter 1880: 85 (nomen novum pro Zethus Schaufuss ); Reitter 1882: 195, 209; Reitter 1884: 418; Raffray 1887: 50, 207; Raffray 1898: 204, 217; Raffray 1904: 505; Raffray 1908: 23; Raffray 1911: 8; Jeannel 1949: 21; Jeannel 1951: 15; Jeannel 1952: 53, 54; Jeannel 1954: 64, 69. Type species: Zethus opacus Schaufuss 1872: 246 .

= Zethus Schaufuss 1872: 246 ; Schaufuss 1877: 7, 11; Schaufuss 1882: CXVIII; Fabricius 1804: 282 ( Hymenoptera ); Pander 1830: 139 (Trilobita); Schaufuss 1888: 97.

Zethopsus omibongensis Byeon and Park , new species zoobank.org/ urn:lsid:zoobank.org:act:B04807E7-F987-4861-8C34-F7152C37983D ( Figs. 2C, G , 3C, G , 8 , 9 , 12C, G , 13C )

Type Material (n = 22, 9♂♂, 13♀♀). Holotype. 1♂ ( NIBR), “ Korea: Gyeongbuk Prov. Sanggeumgok-ri, Yongmun-myeon, Yecheon-gun , 20.IX.2021 36°41′52.4′′N 128°24′18.9′′E, 185m, Sifting, leaf & soil litter U.-J. Byeon ” . Paratypes. 7♂♂, 5♀♀ (3♂♂, 1♀ slide mounted; 4♂♂, 4♀♀ dried; CBNUIC), same data as holotype ; 3♀♀ (dried; CBNUIC), same locality, 19.VII.2019, 36°41′52.0′′N 128°24′18.0′′E, 195 m, sifting soil and leaf litter, U.-J. Byeon ; 1♀ (dried; CBNUIC), same locality, 11.IX.2019, 36°41′51.9′′N 128°24′ 18.8′′E, 176 m, sifting soil and leaf litter, S.-H. Choi, U.-J. Byeon ; 1♂, 4♀♀ (1♂, 2♀♀ slide mounted; 2♀♀ dried; CBNUIC), Cheongdo-gun, Unmunmyeon, Seoji-ri , 02.VII.2021, 35°45′18.9′′N 128°56′41.5′′E, 251 m, sifting soil and leaf litter, M.-H. Song, U.-J. Byeon, J.-I. Shin .

Diagnosis. Adult males of this species can be distinguished from other Zethopsus species by the following combination of genitalic characters: male with lateral margin of aedeagus expanded, median process blunt anteriorly, additional process wrapped around median process, median process with round process bearing small, apical protrusion ( Figs. 12C, G ).

Description. Body length 1.14–1.26 mm (15 specimens measured), color reddish brown, body flattened ( Figs. 2C, G , 3C, G ); head and pronotum of similar width, densely punctate ( Figs. 8A, B , 9A, B ); elytra wider and longer than pronotum, moderately punctate ( Figs. 8C , 9C ); abdomen longer than elytra, moderately punctate ( Figs. 8E, F , 9E, F ); hind wings fully developed. Head. Head with frontal rostrum one-third head width, rostrum longer than vertex, rostrum with distinct dorsal tentorial pits at base, antennal tubercles absent, eyes convex, temples slightly subangular, vertex slightly expanded, single ventral tentorial pit present, genae slightly expanded ( Figs. 8A , 9A ); antenna attached beneath lateral margin of rostrum, composed of ten antennomeres, antennomere I larger than II–IX, II larger than III–IX, III–VIII similar in size, IX larger than III–VIII, X large, clubbed, larger than I–IX ( Figs. 8G , 9G ). Mouthparts. Maxillary palpi with first palpomere extremely reduced, second palpomere ovoid, third palpomere as long as second and angulate at middle, fourth palpomere transverse, attached to third palpomere at middle, with small cap on basal end, rounded on apical end ( Figs. 8J , 9J ); mandibles asymmetrical, left mandible with two subapical teeth, right with four subapical teeth ( Figs. 8I , 9I ); labrum transverse and widest at anterior margin, anterior margin straight, with more than 18 setae ( Figs. 8H , 9H ). Thorax. Pronotum with median discal impression, distinct median antebasal impression divided by longitudinal carina, with lateral antebasal foveae; prosternum with lateral procoxal foveae ( Figs. 8B , 9B ); mesoventrite with two median mesoventral foveae, lateral mesoventral foveae, and promesocoxal foveae ( Figs. 8D , 9D ); metaventrite with median metaventral foveae and lateral mesocoxal foveae ( Figs. 8D , 9D ); each elytron with two basal elytral foveae, with distinct complete carina on lateral margin ( Figs. 8C , 9C ). Abdomen. Abdominal tergite VII longest, IV–VII with mediobasal foveae, VIII with transverse carina at middle ( Figs. 8E , 9E ); abdominal sternites IV–VII with basolateral foveae ( Figs. 8F , 9F ). Aedeagus. Aedeagus asymmetrical, lateral margin expanded, median process blunt anteriorly, additional process wrapped around median process, median process associated with round process bearing small, apical protrusion ( Figs. 12C, G ).

Female. Body size similar to that of male; head slightly smaller ( Fig. 9A ); abdominal sternite IX absent ( Fig. 9F ).

Distribution. South Korea ( Fig. 13C ).

Etymology. This species is named after Mt. Omibong, site of the type locality in Gyeongbuk Province.

Habitat. Specimens of Z. omibongensis were collected by sifting leaf litter and soil in the forest.

Figures

Fig. 2. Adult male habitus. (A–D) Dorsal view, (E–H) Ventral view. A, E) Parapyxidicerus carinatus, B, F) P. koreanus, new species, C, G) Zethopsus omibongensis, new species, D, H) Euplectomorphus pygmaesimilis, new species.

Fig. 3. Adult female habitus. (A–D) Dorsal view, (E–H) Ventral view. A, E) Parapyxidicerus carinatus, B, F) P. koreanus, new species, C, G) Zethopsus omibongensis, new species, D, H) Euplectomorphus pygmaesimilis, new species.

Fig. 8. Adult male Zethopsus omibongensis, new species. A) Head, B) Prosternum, C) Elytra, D) Meso- and metaventrites, E) Abdominal tergites, F) Abdominal sternites, G) Antennae, H) Labrum, I) Mandibles, J) Maxillae.

Fig. 9. Adult female Zethopsus omibongensis, new species. A) Head, B) Prosternum, C) Elytra, D) Meso- and metaventrites, E) Abdominal tergites, F) Abdominal sternites, G) Antennae, H) Labrum, I) Mandibles, J) Maxillae.

Fig. 12. Aedeagus. A, E) Parapyxidicerus carinatus, B, F) P. koreanus, new species, C, G) Zethopsus omibongensis, new species, D, H) Euplectomorphus pygmaesimilis, new species.

Fig. 13. Collection localities.A) Parapyxidicerus carinatus, B) P. koreanus, new species, C) Zethopsus omibongensis, new species, D) Euplectomorphus pygmaesimilis, new species.