Lasinus amamianus, Bekchiev, Rostislav, Hlavac, Peter & Nomura, Shuhei, 2013

Bekchiev, Rostislav, Hlavac, Peter & Nomura, Shuhei, 2013, A taxonomic revision of Tyrini of the Oriental region. V. Revision of the genus Lasinus Sharp, 1874 (Coleoptera, Staphylinidae, Pselaphinae), ZooKeys 340, pp. 21-42 : 37-38

Lasinus amamianus sp. n. Figs 17, 27

Material examined.

(11 ♂♂, 9 ♀♀).HOLOTYPE, ♂, labelled as follows: (p) [Japan, Ryukyus, Kagoshima Pref., Amami-ôshima Is., Mt. Yuidake, 10.VIII.1984, S. Nomura leg.,], red label (p) HOLOTYPE Lasinus amamianus sp. n., Bekchiev, Hlaváč & Nomura det., 2013. (NSMT). PARATYPES: (4 ♂♂, 4 ♀♀) same data as holotype; (1 ♂, 1 ♀) Japan, Ryukyus, Kagoshima Pref., Amami-ôshima Is., Mt. Yuidake, 15.V.1983, S. Nomura leg.; (2 ♂♂, 1 ♀) Japan, Ryukyus, Kagoshima Pref., Amami-ôshima Is., Mt. Yuidake, 8.V.1987, S. Nomura leg.; (1 ♂) Japan, Kagoshima Pref., Tokunoshima Is., Mt. Inutabudake, 3.V.1988, S. Nomura leg.; (3 ♂♂, 3 ♀♀) Japan, Kagoshima Pref., Tokunoshima Is., Yonama, 4.V.1988, S. Nomura leg. (NSMT, PCPH, NMNH, PCSK).

Description.

Body unicoloured, reddish-brown, elytra slightly brighter, maxillary palpi yellow dark, length 2.80-3.00 mm.

Head elongate, about 1.10 times longer than wide, as long as pronotum; median sulcus shallow, reaching level of vertexal foveae. Genae with weak protuberance, covered with erected, dense golden setae.

Antennae about 1.96 mm long (Fig. 17); scapes about 3.40 times longer than pedicels; pedicels 1.40 times shorter than antennomeres III; III slightly longer than wide; IV as long as III; antennomeres V slightly longer than wide; VI about 1.20 times longer than wide; antennomeres VII 1.2 times longer than wide; VIII 1.16 times longer than wide; IX about 1.10 times longer than wide, in male with well-developed tubercles in apical ventral part, in female unmodified; antennomeres X as wide as long; terminal antennomeres about 1.47 times longer than wide.

Pronotum about as wide as long, wrinkly, with weak lateral swellings before lateral foveae; lateral and median setose foveae well-defined; median sulcus thin and deep.

Legs long and slender; protrochanters with large apical spine; profemora with long spine in middle; mesotrochanters at apex with one (male) or two (female) spines; mesofemora with minuscule spine at basal third.

Abdomen slightly wider than elytra, first visible abdominal tergite (IV) finely punctate with dense and long, golden setae; carinae short, distance between them 0.47 of maximal tergal width. Aedeagus (Fig. 27) 0.59 mm long; median lobe weakly narrowed apically, with long and narrow apical lobe; endophallus with two spines and one small lamella; ventral spine large, enlarged, forming large plate, acute at left apex; dorsal spine very big, acute at apex; lamella large, finely dentate on apical part; parameres short and slender, reaching apical lobe.

Differential diagnosis.

Lasinus amamianus and Lasinus saoriae differ from all other species of the genus by the shape of antennae, especially by the presence of tubercles on antennomeres IX. Lasinus amamianus can be readily separated from Lasinus saoriae by the proportion of antennomeres VII and VIII and by the shape of aedeagus.

Etymology.

The species name is associated with the name of the locality, Amami-ôshima Island, where most of the specimens were found.

Distribution.

Japan ( Amami-ôshima, Tokunoshima Islands).