Scydmaenus (Corbulifer) kiwarrakianus, Jałoszyński, 2018

Jałoszyński, Paweł, 2018, ' Monster Scydmaenus' of Australia: revision of subgenus Corbulifer Franz (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 4472 (3), pp. 505-531 : 518-519

Scydmaenus (Corbulifer) kiwarrakianus sp. n.

( Figs 33–35 , 59 , 70 )

Type material. HOLOTYPE: ( AUSTRALIA, NEW SOUTH WALES): ♂, two labels: " AUSTRALIA, NSW / Kiwarrak State / Forest / 31°57'S, 152°27'E / 25 May 1992 " [white, printed], "Tom Gush / In leaf litter / Tom Gush / Collection 3526" [white, printed] ( ANIC).

Paratypes (141 exx.): NEW SOUTH WALES: 45 ♂♂, 58 ♀♀, same data as for holotype ; 5 ♂♂, 5 ♀♀, " AUSTRALIA, NSW / Mount Boss State / Forest / 31°14'S, 152°28'E / 23 May 1992 " [white, printed], " Tom Gush / In leaf litter / Tom Gush / Collection 3509" [white, printed] ; 6 ♂♂, 6 ♀♀, " AUSTRALIA, NSW / Moonpar State / Forest / 30°13'S, 152°40'E / 30 May 1993 " [white, printed], " Tom Gush / In leaf litter / Tom Gush / Collection 3665" [white, printed] ; 5 ♂♂, 4 ♀♀, "30.36S to 30.44S & / 152.05E to 152.10E / Styx R.SF,approx.SE / Wollomombi, NSW / Aug.1993 - Mar.1994 / D.S. Chandler " [white, printed, " Berlesate ANIC 1867 / 870 - 990 m / rotten wood / leaf litter" [white, printed]; 2 ♂♂, 5 ♀♀, Dorrigo N.P., Never Never Picnic Area, 30.22S, 152.48E, 13 - 15.11.1990, T.A. Weir, Berlesate ANIC 1129, rainforest litter (paratypes in ANIC and cPJ).

Diagnosis. Male metatibia gradually and moderately broadened, indistinctly broader than metafemur, broadest at middle, mesal tibial margin sinuate, lateral (external) tibial margin bisinuate with a deep submedian concavity and another, shallower one at middle, dorsolateral glandular 'pocket' present, with mesal margin bearing long setae; aedeagus in dorsal view broadest in basal half and gradually narrowed distad to elongate and subtriangular apex; apical projections long and curved dorsad.

Description. Body of male ( Fig. 33 ) strongly convex, moderately dark brown, covered with setae slightly lighter than cuticle; BL 1.83–1.95 mm (mean 1.91 mm).

Head broadest at small or very small eyes, HL 0.35–0.38 mm (mean 0.36 mm), HW 0.35–0.43 mm (mean 0.40 mm); in microphthalmous males tempora in lateral view as long as about 4 × length of eye, in macrophthlmous males about 2 × length of eye, only slightly convergent posterad and posteriorly bent mesad at a slightly obtuse angle. Punctures on frons and vertex very fine and shallow, inconspicuous; setae short, sparse and suberect. Antennae slender, AnL 0.80–0.88 mm (mean 0.85 mm), antennomeres I–VI each distinctly elongate, VII and VIII each indistinctly transverse, IX and X much larger than VIII, each distinctly transverse, XI about as long as IX–X combined, nearly twice as long as broad.

Pronotum rounded, broadest slightly behind anterior third; PL 0.53–0.58 mm (mean 0.55 mm), PW 0.48–0.53 mm (mean 0.50 mm). Antebasal pits indistinct. Punctures on pronotal disc very fine and shallow, inconspicuous; setae short, sparse and suberect.

Elytra oval, broadest in front of middle; EL 0.93–1.05 mm (mean 1.00 mm), EW 0.73–0.83 mm (mean 0.79 mm), EI 1.21–1.32; apices separately rounded. Punctures small and dense but very shallow, inconspicuous; setae longer and denser than those on pronotum, suberect to erect.

Metatibia ( Fig. 59 ) in dorsal view gradually and moderately broadened, broadest at middle, mesal margin concave in proximal third, convex near middle and nearly straight in distal half, lateral (external) margin bisinuate with one deep submedian triangular concavity and another, shallower one at middle; dorsolateral 'pocket' present, with its mesal margin bearing long setae.

Aedeagus ( Figs 34–35 ) moderately slender; AeL 0.43 mm; in dorsal view median lobe broadest near basal third, gradually and strongly narrowing distad to form a subtriangular, elongate apical portion, with apical projections long and weakly curved distad.

Female. Similar to male, but with unmodified metatibiae; eyes indistinctly smaller than those in microphthalmous males. BL 1.88–1.95 mm (mean 1.93 mm); HL 0.35–0.38 mm (mean 0.37 mm), HW 0.38–0.43 mm (mean 0.40 mm), AnL 0.80–0.85 mm (mean 0.83 mm), PL 0.53–0.58 mm (mean 0.55 mm), PW 0.48–0.53 mm (mean 0.51 mm); EL 0.95–1.03 mm (mean 1.01 mm), EW 0.78–0.85 mm (mean 0.81 mm), EI 1.18–1.28.

Distribution. New South Wales; south-eastern coast of Australia ( Fig. 70 ).

Etymology. Locotypical, after the Kiwarrak State Forest.

Remarks. Males of this species show an unusual variability in the size of composite eyes. The holotype is a specimen with very small eyes, with the tempora as long as 4 × length of eye in lateral view. In some specimens from the same locality (and collected on the same day, by the same method and by the same collector) the eyes are much larger, with the tempora only twice as long as eye. There are no differences in the metatibial modifications and the aedeagal structures between microphthalmous and macrophthalmous forms. In some microphthalmous males the eyes are indistinctly larger than those in the holotype, and in macrophthalmous males the eyes can be as long as 0.4–0.6 length of temple, but no intermediary forms were found. In all females the eyes are very small, indistinctly smaller than those in microphthalmous males. Molecular analysis is necessary to study the genetic structure of what is here interpreted as a single species with two distinct forms of the male eyes; morphological characters support this interpretation.

Males of Scydmaenus kiwarrakianus differ from congeners with similarly gradually broadened metatibiae in the shape of the tibial broadening, especially in the additional shallow concavity at middle of the external margin, and the shape of the aedeagus in dorsal view, which is gradually and strongly narrowed distad.

Figures

FIGURE 70. Distribution of Corbulifer species.

FIGURES 33–35. Scydmaenus (Corbulifer) kiwarrakianus sp. n. Habitus of male (33), aedeagus in dorsal (34) and lateral (35) views.

FIGURES 55–65. Male metatibia in dorsal view. Scydmaenus tamborinensis Franz (55), S. monstrosetibialis sp. n. (56), S. bellenderanus sp. n. (57), S. pseudorobustus Franz (58), S. kiwarrakianus sp. n. (59), S. gushi sp. n. (60), S. gibraltar sp. n. (61), S. eungellanus sp. n., specimen from Mount William (62) and from Peases Lookout (63), S. fishermontanus sp. n. (64), S. super sp. n. (65).