Scaphisoma uenoi, Löbl, 2022

Löbl, Ivan, 2022, On ‘ Scaphisoma tricolor Heller’ from Japan and Errata to the Descriptions of Scaphisoma konvickai Löbl and Toxidium hartmanni Löbl (Coleoptera: Staphylinidae: Scaphidiinae), Japanese Journal of Systematic Entomology 28 (1), pp. 85-88 : 85-87

Scaphisoma uenoi sp. nov.

( Figs 1–4 )

Type material. Holotype [Ogasawara] Is. Hahajima Mt. Kuwanoki 16.vii.1991 T. Ueno leg. ( EUMJ) . Paratypes. 12 males, 4 females, with the same data as the holotype ; 1 male, Hahajima Bonin Is. 15.VII.1969 T. Nakane ; 1 male, Okimura Hahajima, Bonin 2.vi.1976 T. Nakane ; 1 male, Haha-jima Ogasawara 1–8.VII.1986 H. Makihara ; 2 males, Chichijima Bonin Is. 20.VIII.1968 T. Nakane ; 1 male, Is. Chichijima Ogasawara Islands 3 May 1974 H. Yamada leg. ; 1 female, Chichijima Bonin Is. 15.VII.1969 T. Nakane ; 1 male, 1 female, Chichi Jima, Ogasawara 9. and 10.V.1974 Y. Hori leg. ; 1 male, 1 female, [Okinawa: Ryukyu] Hiji – Hiji Fall Kunigami 22.X.1987 M. Sakai leg. ; 1 male, 1 female, Japan: Ryukyus Is. Tokashiki Okinawa Pref. 1–3.xi.1987 T. Ueno leg. ; 1 female, Japan: Ryukyus Nago Is. Okinawa 27.ix.1987 T. Ueno leg. ( EUMJ, MHNG) .

Description. Male. Length 1.90–2.10 mm, width 1.38–1.55 mm. Head, pronotum and hypomere light, reddish-brown. Pronotum along basal margin narrow darkened, sometimes slightly darkened on median or basomedian area. Antennae and mouth-parts yellowish. Exposed scutellum dark brown to blackish. Elytra brown to blackish on anterior two thirds, yellowish or ochraceous on apical fourth to third. Mesanepisterna, metaventrite, metanepisterna, metepimera and ventrites I to III brown, following ventrites lighter, usually yellowish, similar to exposed tergites and apices of elytra, or somewhat darker. Coxae, femora and tibiae about as light as abdominal apex, tarsi still slightly lighter. Antennae long, antennomere II about 3 times as long as antennomere III. Antennomeres IV to VI narrow, similar in width, antennomere V longer than antennomeres IV or VI. Antennomeres VII and IX–XI about twice as wide as antennomere VI, similar in length.

Pronotum lacking microsculpture, with evenly arcuate lateral margins. Lateral margin carinae exposed in dorsal view. Lateral margin striae impunctate. Discal punctation irregular, very fine, with puncture intervals usually 2 to 5 times as large as puncture diameters. Exposed apex of scutellum triangular, with acute tip.

Elytra lacking microsculpture, weakly narrowed apically, with lateral margins nearly evenly arcuate. Lateral margin carinae throughout exposed. Lateral margin striae punctate except near apices, sutural margin not raised. Sutural striae shallow, starting well posterior of level of scutellar tip, weakly converging apically, adsutural areas flat, with each with single puncture row. Apical margins truncate, inner apical angle slightly posterior level of outer apical angles, lacking obvious crenulation or denticles. Prevailing punctation on darkly coloured surface coarse and rather dense, well delimited, with puncture intervals mostly about as large to three times as large as puncture diameters; punctation along bases and lateral margins finer yet well delimited, than on light apical areas denser, much shallower und poorly delimited.

Hypomera and mesanepisterna extremely finely punctate, lacking microsculpture, with distinct pubescence. Mesepimera about 4 times as long as wide and as long as intervals to mesocoxae. Metaventrite bearing strigulate microsculpture on most of mesal areas extended onto part of lateral areas, most of lateral areas without microsculpture; middle of metaventrite convex, with narrow area anterior metacoxal process flattened or slightly impressed; prevailing punctuation on metaventrite very fine and sparse; two small, dense patches of rather coarse punctures present on apicomedian area; with fine punctures forming two admesal rows converging anteriorly, forming inverted V-shaped pattern and delimiting narrow area bearing oblique to longitudinal microstriae; dense antecoxal rows of coarse punctures present. Submesocoxal areas narrow, about 0.03–0.04 mm long, about as long as sixth to fifth of shortest intervals to metacoxae; submesocoxal lines parallel to the mesocoxal margins, coarsely punctured. Metanepisterna slightly convex, impressed below margin of metaventrite, narrowed anteriad, lacking microsculpture, with inner margin nearly straight; punctation very fine and sparse, as that on lateral parts of metaventrite. Metepimera bearing striate microsculpture.

Legs with protibae and metatibiae straight and narrow. Mesotibiae thickened and bent. Tarsomeres I of prolegs and mesolegs strongly widened, wider than apices of respective tibiae. Tarsomeres II of prolegs moderately widened. Tarsomeres II of mesolegs nearly as wide as tarsomeres I.

Abdomen with striate microsculpture. Ventrite I with narrow basomedian patch of coarse punctures, prevailing punctures very fine and sparse, as on rest of exposed abdomen. Submetacoxal areas about 0.05 mm long, as long as fourth of interval between them and apical margin of ventrite I; submetacoxal lines convex, punctate. Apex of ventrite VI expanded to form large mesal lobe about 0.25 mm long, with rounded margin. Aedeagus as Figs 1–4, 1.26 –13.8 mm long.

Female. Head and pronotum brown to blackish, not or only somewhat lighter than elytra. Elytra with apical margins rounded, finely crenulate near inner angles, inner apical angles situated distinctly posterior of level of outer apical angles. Mesotibiae straight, not thickened. Tarsomeres I and II not widened. Ventrite VI not expanded apically. Gonocoxite cylindric, evenly narrow posterior basal section and bent outward, with distinct subapical seta. Gonostyle with one short and one very long apical seta.

Distribution. Japan: Ogasawara and Okinawa Islands.

Etymology. The species is named after the Mr. Teruhisa Ueno (Kyushu University), who collected the bulk of the studied specimens.

Remarks. The S. tricolor group, defined by Löbl & Ogawa (2016), comprises at present 24 species. The characters of three additional species known in females only suggest also their possible close relationship to S. tricolor . Among these species, the males of the following six exhibit similar, conspicuous colour pattern, with the pronotum different sexually (see Löbl & Ogawa, 20216): S. tricolor Heller , S. chujoi Löbl , S. tarsale Löbl , S. tricoloratum Löbl & Ogawa , S. tricolorinotum Löbl & Ogawa and S. uenoi sp. nov. They share also most of the external characters, while their aedeagi provide reliable diagnostic features. The new species may be distinguished from S. tricolor by the apical process of the median lobe with sinuate dorsal and ventral branches and the internal sac lacking tuberculate medial piece. Scaphisoma uenoi is distinguished from the Philippine S. tricoloratum by the strongly expanded parameral laminae and from S. tricolorinotum by the ventral branch of the apical process not gradually narrowed and not curved in dorsal view. Scaphisoma chujoi differs strongly from all these species by the weakly inflexed ventral branch of the apical process, and from S. uenoi also by the parameres less expanded. The median lobe and parameres of S. tarsale are quite similar to those of S. uenoi , however the structure of the internal sac differs significantly, notably by the transverse proximal sclerite and the absence of mesal sclerotized structure.

Figures

Figs 1–4. Aedeagus of Scaphisoma uenoi sp. nov.; 1. Median lobe, dorsal view; 2. Median lobe with internal sac, lateral view; 3. Parameres, ventral view; 4. Internal sac, dorsal view. Scale bars = 0.2 mm.