Bryaxis grandinodus Choi, Park, Lee & Park, 2023

Choi, Yeon-Jae, Park, Sun-Jae, Lee, Seung-Gyu & Park, Jong-Seok, 2023, Five new species of Bryaxis Kugelann (Coleoptera, Staphylinidae, Pselaphinae) from Korea and a nomenclatural note on Bryaxis mahunkai Loebl, ZooKeys 1182, pp. 165-181 : 165

publication ID

https://dx.doi.org/10.3897/zookeys.1182.97346

publication LSID

lsid:zoobank.org:pub:86F5AC45-D35E-4DDF-AB04-2BCBDEEE8407

persistent identifier

https://treatment.plazi.org/id/296C6B58-60CE-41D9-BD87-AAC45B5AC0C5

taxon LSID

lsid:zoobank.org:act:296C6B58-60CE-41D9-BD87-AAC45B5AC0C5

treatment provided by

ZooKeys by Pensoft

scientific name

Bryaxis grandinodus Choi, Park, Lee & Park
status

sp. nov.

Bryaxis grandinodus Choi, Park, Lee & Park sp. nov.

Figs 1 View Figure 1 , 2A, C View Figure 2

Type materials

(N = 11, 6 ♂♂, 5 ♀♀). Holotype male. "Korea: Jeonnam Prov. Dangsan-ri, Gyegok-myeon, Haenam-gun, 18 May 2019, 34°40'53.0"N, 126°38'56.3"E, 211 m, sifting leaf litter & deadwood debris, J.-S. Park, M.-H. Song" (NIBR). Paratypes. 2♂♂, 2♀♀ (CBNUIC, 1♂, 1♀ slide mounted, 1♂, 1♀ dried). "Korea: Jeonbuk Prov. Sinsi island. Sinsido-gil, Okdo-myeon, Gunsan-si, 4 Jul 2022, 35°49'12.2"N, 126°27'35.1"E, 36 m, sifting leaf & soil litter, M.-H. Song, U.-J. Byeon, J.-W. Kang, T.-Y. Jang". 2♂♂ (CBNUIC, dried) "Korea: Jeonbuk Prov. Seonyu island. Seonyubuk-gil, Okdo-myeon, Gunsan-si, 16 Jun 2021, 35°48'36.5"N, 126°24'57.4"E, 25 m, sifting leaf, soil litter & fungi, J.-W. Kang, J.-I. Shin". 1♂, 3♀♀ (CBNUIC, DNA grade). "Korea: Jeonbuk Prov. Seonyu island. 5-1, Seonyunam-gil, Okdo-myeon, Gunsan-si, 4 Jul 2022, 35°48'24.7"N, 126°24'40.3"E, 9 m, sifting leaf & soil litter, M.-H. Song, U.-J. Byeon, J.-W. Kang, T.-Y. Jang".

Diagnosis.

Antennal scapes robust, with bowl-like glandular nodule on inner margin (Figs 1E, F View Figure 1 , 2A View Figure 2 , arrows), 2.45 times as long as pedicels; endophallus of male genitalia with three bifid struts, joined at base (Fig. 1I View Figure 1 ).

Description.

Body reddish brown, antennae, maxillary palpi, and tarsi slightly lighter, length 1.2-1.32 mm, maximum width 0.51-0.58 mm (Fig. 1A-D View Figure 1 ). Setae on body yellowish, long. Head 0.92 times as long as wide (Fig. 1E View Figure 1 ). Frons with U-shaped impression between antennal tubercles; frontal foveae absent; frontal rostrum distinct anteriorly. Vertex slightly convex; longitudinal carina weak; vertexal foveae large. Eyes as long as tempora, with 23-26 facets. Maxillary palpi moderately developed; palpomeres II-III with tubercles; palpomere IV 0.23 mm long and about 3.15 times as long as wide, subcylindrical pseudosegment at apex. Antennae about 0.54 mm long; pedicels subglobose with long setae, 0.89 times as long as wide; antennomere III 1.12 times as long as wide; IV-VIII subequal in length; IX-X transverse, IX 0.64 times as long as wide and X 0.63 times as long as wide; XI largest, pointed at apex, 1.67 times as long as wide (Fig. 1F View Figure 1 ). Pronotum 0.84 times as long as wide and widest at basal 2/3, lateral antebasal foveae connected by antebasal sulcus. Elytra slightly convex, 0.89 times as long as wide and widest at basal 1/4, each elytron with two basal foveae and subhumeral fovea. Legs slender; protibiae without spine (Figs 1G View Figure 1 , 2C View Figure 2 ); metatibiae with spine at apex (Fig. 1H View Figure 1 , arrow). Aedeagus large, 0.37 mm long and 1.69 times as long as wide; penis bulbous and dorsal diaphragm ovoid; parameres short and symmetrical, apices almost encountered, one robust seta and three fine setae on each apex; endophallus divided into three large struts, left dorsal strut branched at basal 1/3 and bifid at apex, right dorsal strut weakly branched basally and bifid dorso-ventrally at apex, ventral strut robust and bifid at apex (Fig. 1I View Figure 1 ).

Sexual dimorphism. Female eyes shorter than tempora, composed of 11 facets; antennal scapes subcylindrical, without modification; metatibial spines absent.

Remarks.

Adults of this species are very similar to Bryaxis koltzei (Reitter, 1887) in the general body characters, but can be distinguished by the shape of the antennal scapes and its glandular nodule (Fig. 2A View Figure 2 , arrow) and the spineless protibiae in the male (Fig. 2C View Figure 2 ).

Comments.

The localities of B. grandinodus sp. nov. probably overlap with those of B. koltzei (Reitter) given that the latter are distributed across the entire country (Fig. 11 View Figure 11 ).

Etymology.

The specific epithet is a combination of the Latin words grandis ( “large”, masculine) and nodus ( “knob”, masculine) and refers to the shape of the glandular nodules on the male antennal scapes.

Habitat.

The holotype was collected by sifting leaf litter in mixed forest. Paratypes were collected by sifting leaf litter and soil.

Distribution.

Korea (Haenam-gun, Jeollanam-do; Gunsan-si, Jeollabuk-do).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Staphylinidae

Genus

Bryaxis