Stenichnus (s. str.) bukpyeongensis, Song & Byeon & Park, 2024

Song, Min-Ho, Byeon, Ui-Joung & Park, Jong-Seok, 2024, A Taxonomic Study of the Genus Stenichnus Thomson (Coleoptera: Staphylinidae: Scydmaeninae) in Korea with Descriptions of Three New Species, The Coleopterists Bulletin 78 (2), pp. 141-149 : 145-147

Stenichnus (s. str.) bukpyeongensis Song, Byeon, and Park, new species zoobank.org/ urn:lsid:zoobank.org:act:F36378D4-AA44-4CCF-8FF8-B2EAAF48A13B ( Figs. 2B, E , 3B, E , 4D–F , 5 )

Type Material (n = 19, 9♂♂ 10♀♀). Holotype. 1♂ (card mounted, CBNUIC), “ Korea: Gangwon Prov. 256-1, Najeon-ri, Bukpyeong-myeon, Jeongseon-gun , 23IV2020, 37°26′23.7″N 128°37′35.3″E, 485m, Sifting, Soil & Leaf litter J.-Y. Kang, J.-W. Kim ”.

Paratypes. Gangwon Prov.: 4♂♂ 2♀♀ (1♂ 1♀ slide mounted, 1♂ card mounted, CBNUIC), 256-1, Najeon-ri, Bukpyeong-myeon, Jeongseon-gun, 23 iv 2020, 37°26′23.7′′N 128°37′35.3′′E, 485 m, sifting soil and leaf litter, U.-J. Byeon, T.-Y. Jang ; 1♂ 1♀ ( CBNUIC), Yagsu-gul, Hwaam-myeon, Jeongseon-gun, 16 xii 2019, 37°19′11.6′′N 128°46′48.1′′E, 483 m, sifting soil and leaf litter near stream, J.-S. Park, J.-Y. Kang, J.-W. Kang, Y.-J. Choi, M.-S. Jang, U.-J. Byeon, T.-Y. Jang, J.-W. Kim ; 1♂ 1♀ (1♀ card mounted, CBNUIC), Jangyeol-ri, Bukpyeong-myeon, Jeongseon-gun, 24 iv 2020, 37°28′33.8′′N 128°42′16.6′′E, 403 m, sifting soil and leaf litter, J.-Y. Kang, J.-W. Kim ; 1♀ ( CBNUIC), Jangyeol-ri, Bukpyeong-myeon, Jeongseon-gun, 24 iv 2020, 37°28′33.8′′N 128° 42′16.6′′E, 403 m, sifting soil and leaf litter, U.-J. Byeon, T.-Y. Jang ; 1♂ ( CBNUIC), Najeon-ri, Bukpyeong-myeon, Jeongseon-gun, 21 viii 2019, 37°26′02.0′′N 128°36′57.9′′E, 782 m, sifting soil and leaf litter near stream, M.-S. Jang, J.-Y. Kang, U.-J.Byeon ; 1♂ (95% EtOH, CBNUIC), Odaecheon-ro, Bukpyeong-myeon, Jeongseon-gun, 21 viii 2020, 37°28′02.7′′N 128°36′57.5′′E, 400 m, sifting soil, leaf litter, fungi, S.-H. Choi ; 2♀♀ ( CBNUIC), 104-2, Jikjeon-ri, Sabuk-eup, Jeongseon-gun, 16 xii 2019, 37°16′15.3′′N 128°49′56.7′′E, 620 m, sifting leaf litter & soil near stream, J.-S. Park, J.-Y. Kang, J.-W. Kang, Y.-J. Choi, M.-S. Jang, U.-J. Byeon, T.-Y. Jang, J.-W. Kim ; 2♀♀ (1♀ card mounted, 1♀ 95% EtOH, CBNUIC), Odaecheon-ro, Bukpyeong-myeon, Jeongseon-gun, 23 iv 2020, 37°28′03.4′′N 128°36′53.3′′E, 594 m, sifting leaf litter and soil, U.-J. Byeon ; 1♀ (95% EtOH, CBNUIC), 193, Gujeol-ri, Yeoryang-myeon, Jeongseon-gun, 24 iv 2020, 37°30′57.6′′N 128°45′18.8′′E, 510 m, sifting leaf litter, soil, and formicary, Y.-J. Choi, U.-J. Byeon .

Diagnosis. External characters of this species are very similar to those of Stenichnus montanus Jałoszyński and Stenichnus bellulus Jałoszyński , but it can be distinguished from S. montanus by the smaller body (body length of S. montanus : 1.57 mm), the longer aedeagus ( S. montanus : 0.22 mm), base of the endophallus which is flattened (for aedeagus of S. montanus see Jałoszyński 2009: figs. 3, 4), and hind wings absent and from S. bellulus by the small body (body length of S. bellulus : 1.49–1.6 mm), endophallus simple (for aedeagus of S. bellulus see Jałoszyński 2004: figs. 3A–C), and hind wings absent.

Description. Male. BL 1.39–1.43 mm (5 specimens measured), strongly elongate and slender, reddish-brown with yellowish setae, legs and maxillary palpi light brown ( Fig. 2B ).

Head wider than long, HL 0.21–0.22 mm, HW 0.25–0.26 mm; clypeus broadly expanded; frons between eyes strongly convex; vertex weakly convex; eyes large and strongly protruding, diameter 0.076 mm; tempora shorter than eye, strongly convergent posteriad; punctures on vertex and frons fine and sparse; setae sparse, long, and suberect; antennae slender, AnL 0.58–0.60 mm, antennomeres 1–2 approximately 1.8 times longer than wide, 3–6 longer than wide, 7 slightly as long as wide, 8–10 wider than long, 11 about twice as long as 10 and subconical.

Pronotum as long as wide, widest near anterior third, PL 0.36–0.38 mm, PW 0.32–0.33 mm, anterior margin slightly rounded, narrowest near posterior third, base with four pits located on each side, with long, sparse setae and fine punctures.

Elytra oval, elongate, widest near middle, EL 0.79–0.83 mm, EW 0.52–0.54 mm, EI 1.46–1.59, humeral calli reduced; each elytron with one distinct and one indistinct fovea; punctures distinct, punctation of anterior half denser than that of posterior half, with long, suberect, moderately dense setae; hind wing absent.

Legs moderately long and slender, dorsal clavate margin of profemur moderately expanded and weakly convex ( Fig. 3B ).

Aedeagus moderately stout, oval, AeL 0.28 mm; median lobe bears meso-ventral projection surrounded by triangular structure; endophallus with weakly sclerotized and denticulate structure; parameres wide, not reaching apex of median lobe, each paramere with six apical setae ( Figs. 4D–F ).

Female. BL 1.40–1.42 mm (5 specimens measured), HL 0.21 mm, HW 0.25 mm, AnL 0.57 mm, PL 0.35 mm, PW 0.34 mm,EL 0.73 mm, EW 0.54 mm, EI 1.35. Eyes about 0.01 mm smaller than in male; elytra distinctly shorter than in males ( Fig. 3E ); hind wing absent.

Etymology. This species is named after the holotype locality, Bukpyeong-myeon, Jeongseon-gun, Gangwon Province.

Distribution. South Korea ( Fig. 5 ).

Habitat. Specimens of S. bukpyeongensis were collected by sifting leaf litter and soil in a mixed forest.

Figures

Fig. 2. Habitus of Stenichnus spp. A–C) Male, D–F) Female. A, D) S. rhinocerosus, new species, B, E) S. bukpyeongensis, new species, C, F) S. satus, new species.

Fig. 3. Profemora of Stenichnus spp. A–C) Male, D–G) Female. A, D) S. rhinocerosus, new species, B, E) S. bukpyeongensis, new species, C, F) S. satus, new species.

Fig. 4. Aedeagi of Stenichnus spp. A, D, G) Dorsal, B, E, H) Ventral, C, F, I) Lateral. A–C) S. rhinocerosus, new species, D–F) S. bukpyeongensis, new species, G–I) S. satus, new species.

Fig. 5. Collection localities for Stenichnus in South Korea.