Platydomene sinuosa, Assing, 2010

Assing, Volker, 2010, On the Lathrobiina of Taiwan (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 60 (2), pp. 301-361 : 321-323

Platydomene sinuosa sp. n. ( Figs 79-85 )

Type material:

Holotype ♂ [slightly teneral]: " Taiwan, ChyrDuan , Ilan. Hsien, 1200 m, Fauch. bord route, L. LeSage, LL90-08 / Holotypus ♂ Platydomene sinuosa sp. n. det. V. Assing 2010" (cAss).

Description:

Body length 8.3 mm. Habitus as in Fig. 79 . Coloration: head and pronotum dark-brown; elytra yellowish brown; abdomen dark-brown with paler apex; legs brown; antennae dark-brown, with antennomeres I and II reddish-brown.

Head of subquadrate shape with rounded posterior angles, approximately as wide as long ( Fig. 80 ); punctation dense and relatively coarse, with the interstices distinctly narrower than the diameter of the punctures, except for the more sparsely punctured median dorsal area and frons; interstices without microsculpture; eyes moderately large, slightly more than 1/3 the length of postocular portion in dorsal view. Antenna slender, 3.5 mm long; antennomere II slightly more than twice as long as wide; III slightly longer than II and almost 3 times as long as wide; IV-IX somewhat shorter than III and approximately twice as long as wide; X slightly less than twice as long as wide; XI with somewhat coniform apex ( Fig. 81 ).

Pronotum approximately 1.25 times as long as broad and 0.9 times as wide as head ( Fig. 80 ); punctation similar to that of head; along midline with narrow impunctate band; interstices without microsculpture.

Elytra approximately (0.97 x) as long as pronotum ( Fig. 80 ); punctation well-defined, relatively coarse, and irregular. Hind wings fully developed. Legs not conspicuously slender.

Abdomen with fine and dense punctation and with shallow microsculpture; posterior margin of tergite VII with palisade fringe; posterior margin of tergite VIII strongly convex.

♂: sternite VII posteriorly broadly concave and with row of relatively long black marginal setae ( Fig. 82 ); sternite VIII in the middle with oblong triangular impression, this impression with numerous peg-setae, posterior excision relatively shallow, posterior margin in the middle of this excision with obtusely angled projection ( Fig. 83 ); aedeagus with long, in lateral view S-shaped ventral process ( Figs 84-85 ).

♀: unknown.

Comparative notes:

The new species is readily distinguished from all its congeners by the morphology of the aedeagus, as well as by the shape and chaetotaxy of the male sternites VII and VIII. The only other PlatydomenePlatydomene species previously known from Taiwan is P. taiwanensis WATANABE, 1991 , which is of testaceous coloration and which has much shorter elytra and reduced hind wings, a head of elipsoid shape, much shorter eyes, and a much more oblong pronotum. According to SMETANASMETANA (2004), the only other representatives of the genus known from the Eastern Palaearctic region are P. anguina (SHARP, 1874) , P. carinicolliscarinicollis ( SHARP, 1889) , P. funebrisfunebris ( SHARP, 1889) , and P. nobilisnobilis ( SAWADA, 1965) , all of them recorded only from Japan. Very recently, seven additional species were described from Japan, P. hakusana , P. kojimai , P. nikkoensis , and P. hirogawaranahirogawarana by WATANABE (2008), as well as P. daibosatsuensis , P. flavipes , and P. iidesanaiidesana by WATANABE (2009). All these species are distinguished from P. sinuosasinuosa by the shape of the aedeagus and additionally as follows:

Platydomene anguinaanguina has a forebody of reddish coloration and shorter elytra; P. carinicolliscarinicollis is of reddish coloration, has a suborbiculate and (posteriorly) finely punctured head, elytra with a basally almost linear arrangement of the punctures, and differently modified male sternites VII and VIII; P. funebrisfunebris is somewhat smaller and of blackish coloration; in P. nobilisnobilis the coloration is dark- er (dark-brown to black), antennomere III is as long as II, the hind wings are completely reduced, and the male secondary sexual characters are of completely different morphology. Platydomene hakusana , P. kojimai , P. nikkoensis , P. hirogawarana , P. daibosatsuensis , P. flavipes , and P. iidesana all have distinctly shorter elytra.

For illustrations of the male sexual characters of all the compared species, except for those described by SHARP (1874, 1889), see SAWADA (1965) and WATANABE (1991, 2008, 2009).

Etymology:

The specific epithet (Latin, adjective: curved) alludes to the shape of the aedeagus in lateral as-

pect.

Distribution and natural history:

The type locality is situated in Ilan Hsien, northeastern Taiwan, at an altitude of 1200 m. The holotype is slightly teneral .

Figures

Figs 79-85: Platydomene sinuosasinuosa sp. n.: habitus (79); forebody (80); antenna (81); male sternite VII (82); male sternite VIII (83); aedeagus in lateral and in ventral view (84-85). Scale bars: 79-81: 1.0 mm; 82-85: 0.5 mm.