Stilicoderus harpago, Assing, 2017

Assing, Volker, 2017, On Stilicoderus VI. Two new species from South Vietnam and additional records (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 49 (1), pp. 369-376 : 374-375

Stilicoderus harpago nov.sp. ( Figs 10-15 , 17 )

T y p e m a t e r i a l: Holotype 3: "S VIETNAM: Lâm Dông Prov., Lac Durong Distr., Bidoup Nuiba Natl Park, surr. Giang Ly Ranger Station (1420-1460 m a.s.l.) 16-21.VI.2015 / legit L. Bartolozzi, G. Chelazzi, S. Bambi, F. Fabiano, E. Orbach, V. Sbordoni (n. Magazzino 3023) / Holotypus 3 Stilicoderus harpago sp.n. det. V. Assing 2017" (VNMN). Paratypes: 2♀♀: same data as holotype (MZUF, cAss) [paratype in MZUF registered as MZUF 18320].

E t y m o l o g y: The specific epithet (Latin: grapnel, grappling hook) is a noun in apposition and alludes to the shape of the ventral process in lateral view.

D e s c r i p t i o n: Body length 7.2-7.8 mm; length of forebody 4.5-4.8 mm. Coloration: body black; elytra with a relatively large pale-reddish spot extending diagonally from the humeral angles to the posterior two-fifths or the posterior third of the suture (i.e., scutellar portion, suture, and the posterior third to two-fifths black); legs black with slightly paler tarsi; antennae brown with blackish antennomere I.

Head ( Fig. 10 ) 1.01-1.08 times as broad as long, weakly convex in cross-section; lateral margins behind eyes broadly convex in dorsal view; punctures dense, moderately coarse, and of oval shape; interstices narrower than diameter of punctures, without microsculpture. Eyes strongly convex, 0.3-0.4 times as long as postocular region from posterior margin of eye to posterior constriction of head. Antenna ( Fig. 11 ) 2.3-2.4 mm long; antennomere IV approximately twice as long as broad, shorter than III; antennomeres V- X of gradually decreasing length; preapical antennomeres approximately as broad as long.

Pronotum ( Figs 10 , 17 ) 1.06-1.10 times as long as broad and 0.84-0.85 times as broad as head, moderately convex in cross section; punctation predominantly arranged in longitudinal rugae, defined punctures present only near pronotal margins; midline with pronounced, glossy impunctate band.

Elytra ( Fig. 10 ) 0.87-0.91 times as long as pronotum; punctation composed of coarse and somewhat irregularly distributed macropunctures and dense micropunctures; interstices without microsculpture.

Abdomen with fine and dense punctation; microsculpture of anterior impressions of tergites III-VI pronounced, less pronounced on remainder of tergal surfaces.

3: posterior margin of sternite VII broadly convex, in the middle indistinctly concave ( Fig. 12 ); posterior incision of sternite VIII very narrow anteriorly ( Fig. 13 ); aedeagus ( Figs 14-15 ) 1.15 mm long, with a ventral process of distinctive shape and with a pair of curved and acute apical structures.

C o m p a r a t i v e n o t e s: Previously, five Stilicoderus species were known from Vietnam, all of them with reddish spots on the elytra. Aside from the highly distinctive aedeagus, S. harpago is distinguished from them as follows:

from S. fenestratus FAUVEL, 1895 by blackish legs, a more transverse head, less convex pronotum and elytra, rugose punctation of the pronotum, and a male sternite VIII of completely different shape;

from S. denticulatus ASSING, 2013 by a larger and more depressed body, blackish legs, a transverse head with more convex lateral margins posteriorly (dorsal view), larger eyes, rugose punctation of the pronotum, denser macropuncation on the elytra, a matt abdomen, and a male sternite VIII of different shape;

from S. feae FAUVEL, 1895 by smaller body size, more slender head and pronotum, blackish legs, rugose punctation of the pronotum, and a male sternite VIII of completely different shape;

from S. discalis FAUVEL, 1895 by a longer body, a much more slender and less depressed forebody, darker and longer legs, less dense punctation of the head, a less matt pronotum with differently rugose punctation, shorter legs, and a male sternite VIII of different shape;

from S. strigosus (ROUGEMONT, 1985) by larger body size, a much more slender and less depressed forebody, distinctly smaller and less convex eyes, darker and longer legs, less dense and finer punctation of the head, a less matt pronotum with the rugose punctation not distinctly oblique, shorter legs, and a male sternite VIII of different shape.

For illustrations of S. fenestratus , S. feae , S. discalis , S. strigosus , and S. denticulatus see ROUGEMONT (1986) and ASSING (2013a), respectively.

Stilicoderus harpago is attributed to the S. discalis rather than the S. signatus group primarily based on the rugose punctation of the pronotum. It is distinguished from the species previously attributed to this group (e.g., S. discalis , S. strigosus ) by a more slen- der and less depressed body with longer legs.

D i s t r i b u t i o n: The type locality is identical to that of S. bisinuatus .

Figures

Figs 8-15: Stilicoderus bisinuatus nov.sp. (8-9) and S. harpago nov.sp. (10-15): (8, 12) male sternite VII; (9, 13) male sternite VIII; (10) forebody; (11) antenna; (14-15) aedeagus in lateral and in ventral view. Scale bars: 10-11: 1.0 mm; 8-9, 12-15: 0.5 mm.

Figs 16-17: Stilicoderus bisinuatus nov.sp. (16) and S. harpago nov.sp. (17): (16) antero-median dorsal portion of head; (17) pronotum. Scale bars: 17: 0.5 mm; 16: 0.1 mm.