Horaeomorphus fakfakensis, ski, 2009

ski, P. Jałoszy, 2009, Four New Species Of Horaeomorphus Schaufuss From The Oriental Region (Coleoptera: Staphylinidae, Scydmaeninae), Raffles Bulletin of Zoology 57 (2), pp. 297-303 : 301-302

Horaeomorphus fakfakensis , new species

( Figs. 1c , 3a, b )

Material examined. – Holotype. Male , two labels “ IRIAN JAYA:Fakfak \ Kokas Insel Ogar \ 13.VIII.1996 \ leg. SCHÜLE/ STÜBEN” [pale blue, printed], “ HORAEOMORPHUS \ fakfakensis m. \ HOLOTYPUS \ det. P. JAŁOSZY SKI, ‘08” [red, printed] ( SMNS).

Diagnosis. – This moderately large Horaeomorphus can be distinguished from all other species of the genus on the basis of the following set of characters: pronotum very broad, disc nearly circular, with relatively small oval median part covered with large, deep and dense punctures while remaining surface bears small and very shallow punctures; base of pronotum with five pits, without groove; legs nonmodified.

Male. – Body ( Fig. 1c ) moderately large (length 2.08 mm), pronotum and elytra very broad, moderately strongly convex, dark brown, vestiture slightly lighter than cuticle. Head broadest at large, strongly convex eyes, length 0.33 mm, width 0.43 mm; tempora slightly shorter than eye in dorsal view, weakly and regularly rounded up to posterior 2/3, where they are strongly bent toward occipital constriction; vertex weakly convex, with pair of small and shallow pits located near posterior margins of supraantennal tubercles; frons weakly convex; supraantennal tubercles very distinct, strongly raised, well delimited from frons but indistinctly delimited from vertex. Punctures on vertex and frons very fine but sharply marked, very sparse, unevenly distributed, separated by spaces 4–6× as long as puncture diameters; setae moderately long, sparse, suberect to erect. Antennae moderately slender, shorter than half length of body, length 0.90 mm; relative lengths of antennomeres (shortest antennomere VII as 1): 1.59; 1.36; 1.36; 1.36; 1.36; 1.27; 1; 1.36; 1.36; 1.36; 2.27.

Pronotum very broad and nearly circular, broadest between middle and anterior third, length 0.68 mm, width at base 0.43 mm, maximum width 0.65 mm; anterior and lateral margins rounded together; subbasal constriction barely marked; hind angles obtuse and blunt; posterior margin nearly straight; posterior collar very short, delimited from disc by transverse dorsal row of five pits; median pit moderately large, deep, two lateral pairs composed of smaller and shallower pits, external ones are shifted anteriorly. Disc with median oval area densely covered with large and deep, oval or slightly irregular in shape punctures separated by spaces 1–2× as long as puncture diameters; remaining surface of disc with similarly dense, but much smaller and very shallow punctures; vestiture moderately dense and long, suberect.

Elytra oval, very broad and relatively short, as convex as pronotum, broadest near anterior fourth, length 1.08 mm, width 0.73 mm, EI 1.48. Base of elytra arcuate, so that humeri are projecting anteriorly; humeral calli moderately distinct, delimited from adsutural region by short and deep, broad basal impressions; basal foveae indiscernible; apices of elytra separately rounded. Punctures in anterior 2/3 of elytra much more distinct than those on sides of pronotum, but much smaller than those on median part of pronotal disc, separated by spaces about equal to puncture diameters; punctures become gradually smaller and shallower toward apices and lateral margins of elytra. Vestiture similar to that on pronotum but slightly longer and slightly more suberect. Metathoracic wings not studied.

Legs non-modified.

Aedeagus ( Figs. 3a, b ) 0.30 mm in length; relatively stout; median lobe with subtrapezoidal apical part distinctly projected in middle; internal sac relatively simple and lightly sclerotized, with small central complex; parameres slender, with apices reaching apex of median lobe, each with three very short apical setae.

Female. – Unknown.

Etymology. – Locotypical, after the type locality, Indonesian district Fakfak.

Distribution. – Indonesia (New Guinea): Irian Jaya Barat.

Remarks. – This species is most similar to H. sarawakensis Franz, 1992 (from W Malaysia and Borneo), H. valdepunctatus Franz, 1984 (W Malaysia), H. punctatissimus Franz, 1992 (Borneo, Sumatra and Siberut Is.), and H. samosirensis described below. Together with H. fakfakensis , these taxa share a similar body form, with very broad, nearly circular pronotum, and stout elytra. Horaeomorphus fakfakensis can be distinguished from H. sarawakensis , H. punctatissimus and H. samosirensis on the basis of nearly straight metatibiae, while those in the three species are strongly bent. Horaeomorphus valdepunctatus , in turn, has only slightly curved metatibiae, but metatrochanters in males are strongly modified, forming a long projection; metatrochanters in H. fakfakensis are non-modified. This species is the first member of the genus known to occur in New Guinea.

Figures

Fig. 1. Dorsal habitus of holotype males: a, Horaeomorphus imitator, new species; b, Horaeomorphus minor, new species; c, Horaeomorphus fakfakensis, new species; d, Horaeomorphus samosirensis, new species (d). Scale bar = 0.5 mm.

Fig. 3. Aedeagus in ventral (a, c) and lateral (b, d) views: a, b, Horaeomorphus fakfakensis, new species, c, d, Horaeomorphus samosirensis, new species. Scale bar = 0.2 mm.