Scaphisoma coeruleum, Löbl, 2002

Löbl, I., 2002, New Species Of Scaphisoma Leach (Coleoptera: Staphylinidae: Scaphidiinae) From Mt. Wilhelm, Papua New Guinea, Acta Zoologica Academiae Scientiarum Hungaricae 48 (3), pp. 181-189 : 182-184

Scaphisoma coeruleum sp. n.

( Figs 1–2 )

Holotype male, labelled: NewGuinea /NE/ Mt. Wilhelm, Field Station, 16.IX.1968 /No.

NG-M.R.25/ leg. Dr. I. Loksa (HNHM).

Paratypes with same data as holotype but: 3200 m, 14.IX. /No. NG-M. R. 20 and 21/, 2 males and 4 females ( HNHM, MHNG); Mt. Wilhelm 3600 m, Iambuka Ridge, 18.IX.1968 / No .

NG-M.R. 29–31/ leg. I. Loksa, 2 females ( HNHM, MHNG) .

Description. Length 1.5 mm. Head, pronotum and most of elytra dark, with distinct blue or green metallic shine. Apices of elytra and of abdomen, and legs dark brown. Ventral side of thorax and most of abdomen black. Antennae ochreous, with apical segments darkened. Length ratio of antennalsegmentsas:III6,IV8,V11,VI11,VII14,VIII10,IX10,X13,XI17(holotype);segment III comparatively wide, only 1.5 times as long as wide, segment IV almost 3 times as long as wide, narrower than segment III; segments V and VI each about as wide as segment IV, almost 4 times as longaswide;segmentVIIalmost3timesaslongaswide,muchwiderthansegmentVI;segmentVIII about 2.5 times as long as wide, segment XI about twice as long as wide. Eyes conspicuously large, covering lateral parts of head. Pronotum long, moderately narrowed anteriorly, with lateral contours oblique near base, slightly arcuate in anterior half. Lateral pronotal ridges not visible in dorsal view. Pronotal punctation dense, extremely fine and shallow. Pubescence very short but well visible. Scutellum completely covered by pronotal lobe. Elytra very weakly narrowed toward base, widest posterior basal third, from widest point moderately narrowed toward apices. Lateral elytral contours slightly arcuate in apical half. Sutural margin not raised. Inner apical angle lying posterior level of outer apical angles; apical margins edentate, arcuate. Sutural striae fine, diverging from apices toward middle third of sutural length, parallel in anterior third of sutural length, ending posterior line of pronotal lobe, not curved laterally. Lateral margin ridge not visible at dorsal view. Lateral striae curved at base, not extending along basal margin. Punctation of elytra similar to that on pronotum. Metathoracic wings strongly reduced, present as filament-like rudiments. Ventral side of thorax lacking microsculpture and very finely punctate. Mesepimeral ridge slightly longer than interval to mesocoxa. Metasternum comparatively short, convex between mesocoxae, flattened between metacoxae, lacking impressions. Mesocoxal lines parallel to coxae, indistinctly punctate. Mesocoxal areas narrow, 0.02 mm long, about as long as one-third of shortest interval to metacoxae. Metepisterna wide apically, strongly narrowed anteriorly, with inner margin slightly arcuate, hardly impressed belowplane of metasternum. Abdomen very finely punctate and with punctulate microsculpture, latter absent from 1st exposed sternite. Metacoxal lines parallel, 0.03 mm long, with distinct marginal punctures. Tibiae straight, slender.

Male sexual characters. Protarsi hardly widened. Aedeagus ( Figs 1 & 2 ) 0.35–0.40 mm long. Median lobe with very long, sinuate apical process and basal bulb weakly sclerotized, prominent and narrowed apically. Apical process of median lobe strongly curved ventrally and very thin (lateral view), tapering at dorsal view. Parameres symmetrical, strongly widened apically. Internal sac with extruded part of flagellum very long.

Comments. Scaphisoma coeruleum resembles S. papua by its metallic shine of its body. These two species are the only known Scaphisomatini that have a metallic shine. The other scaphidiines with body having a metallic shine are members of the genus Scaphidium OLIVIER. S. coeruleum may be easily distinguished from S. papua by the blue pronotum and elytra, the shorter antennal segment 3 and the parameres comparatively longer, widened apically and lacking membranous lobes.

Figures

Figs 1–4. Aedeagus of Scaphisoma species: 1–2 = S. coeruleum sp. n., scale bar = 0.1 mm; 3–4: S. fenestratum sp. n., scale bar 0.2 mm