Hlavaciellus angustifrons, Jałoszyński, Paweł, 2011

Jałoszyński, Paweł, 2011, Hlavaciellus Jałoszyński, 2006: eleven new species, detailed morphology and systematic position within Cephenniini (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 2763, pp. 1-33 : 7-8

Hlavaciellus angustifrons sp. n.

( Figs. 3 , 6 , 18, 19 )

Type material. Holotype: MALAYSIA: ɗ, " SABAH: Crocker Ra. \ 1600 m, km 51 rte \ Kota Kinabalu– \ Tambunan, 18.V.87 \ Burckhardt - Löbl" [white, printed], " HLAVACIELLUS \ angustifrons m. \ det. P. JAŁOSZYŃSKI, '09 \ HOLOTYPUS " [red, printed] ( MHNG). Paratype: MALAYSIA: ɗ, same data as the holotype ( PCPJ).

Diagnosis. Head in males with pair of deep and broad impressions running from posterior margin of each eye anteriorly and towards middle where they are separated by longitudinal convexity of frons.

Description. BL 1.88–1.90 (1.89). Body of male ( Fig. 3 ) moderately convex, pigmentation light brown, vestiture yellowish.

Head ( Fig. 6 ) large, HL 0.30, HW 0.48–0.50 (0.49); vertex convex, with highest point located in middle of anterior part, anterior margin broadly V-shaped and bordered anteriorly by broad and deep groove interrupted in middle by narrow median longitudinal convexity of frons which is additionally bordered at each side by longitudinal lateral tubercle; anterior part of frons confluent with clypeus and nearly flat; supraantennal tubercles prominent, distinctly separated from frons; eyes large, strongly convex and coarsely faceted. Punctures and setae as in Fig. 6 . Antennae nearly as long as 0.8 BL, slender, gradually thickened up to antennomere X, uniformly covered with thin, long, dense and suberect setae, antennomeres VII–X with slant apical margins (i.e., external lateral margin is longer than internal one), AnL 1.45, antennomere I 1.4x as long as broad; II distinctly narrower and shorter than I, about as long as broad; III slightly larger than II, 1.2x as long as broad; IV slightly broader and distinctly longer than II, 1.3x as long as broad; V slightly broader and distinctly longer than IV, 1.3x as long as broad; VI slightly broader and distinctly longer than V, 1.3x as long as broad; VII–IX subequal in length and width, each slightly broader and distinctly longer than VI, about 1.3x as long as broad; X distinctly larger than IX, 1.2x as long as broad; XI about as broad as X and slightly shorter than IX–X together.

Pronotum in dorsal view subtrapezoidal with strongly convex anterior margin, broadest near anterior third, PL 0.55–0.58 (0.56), PW 0.73; sides strongly rounded in anterior third, behind broadest place broadly concave; hind angles sharp but not acute; posterior margin shallowly bi-emarginate; ante-basal pits very shallow and diffused, equally distant from posterior and lateral margins of pronotum; lateral edges indistinctly swollen. Pronotal disc glossy, uniformly covered with very fine and shallow punctures separated by spaces 1– 2 x as wide as puncture diameters. Setae long and dense, suberect to erect.

Elytra oval, relatively long, broadest between anterior fourth and third, EL 1.03–1.05 (1.04), EW 0.85–0.88 (0.86), EI 1.17–1.24; basal pit on each elytron small but distinct, located very close to scutellum; subhumeral lines sharply marked, as long as 0.3x EL, only slightly divergent, each developed as border between higher humeral region and lower adsutural area; suture in anterior third slightly elevated; apices of elytra separately rounded. Punctures on basal third of each elytron small but more distinct and denser than those on pronotum, gradually reducing in diameter and depth toward lateral margins and apices; setae similar to those on pronotum. Hind wings well developed.

Legs slender and very long; protibiae barely noticeably bent outwards in middle; meso- and metatibiae straight.

Metaventrite with relatively deep postmesocoxal impressions occupying about half length of ventrite.

Aedeagus ( Figs. 18, 19 ) slender, AeL 0.31; median lobe with subtriangular, non-separated apical part; internal armature slightly asymmetrical; parameres in lateral view relatively slender, with ventral margin bent twice in subapical region and nearly straight apical part.

Female. Unknown.

Distribution. East Malaysia: Borneo, Sabah.

Etymology. The name refers to the unique narrow frontal convexity in males of this species.

Remarks. No other species of Hlavaciellus has a similar modification of the frons. However, the aedeagus of H. angustifrons is relatively unremarkable and only the weakly curved apices of parameres seem unique enough to provide a reliable diagnostic character.

Figures

FIGURES 1 – 3. Dorsal view of holotypes of Hlavaciellus, males. 1, H. peninsularis sp. n. 2, H. cirrus sp. n. 3, H. angustifrons sp. n. Scale bars: 1 mm.

FIGURES 4 – 9. Modifications of head in frontal view. 4, Hlavaciellus peninsularis sp. n. 5, H. cirrus sp. n. 6, H. angustifrons sp. n. 7, H. decoratus sp. n. 8, H. smetanai sp. n. 9, H. bifoveatus sp. n. Scale bars: 0.1 mm.

FIGURES 13 – 23. Aedeagus in ventral (13, 15, 18, 20, 22) and lateral (14, 16, 19, 21, 23) views, and head of male in lateral view (17). 13, 14, Hlavaciellus peninsularis sp. n. 15 – 17, H. cirrus sp. n. 18, 19, H. angustifrons sp. n. 20, 21, H. decoratus sp. n. 22, 23, H. smetanai sp. n. Scale bars: 0.2 mm (13 – 16, 18 – 23), 0.1 mm (17).