Cephennomicrus matangensis, Jałoszyński, 2019

Jałoszyński, Paweł, 2019, Four new Oriental species of the ‘ Cephennomicrus group’ (Coleoptera: Staphylinidae: Scydmaeninae), Zootaxa 4679 (3), pp. 553-562 : 556

Cephennomicrus matangensis sp. n.

( Figs 2, 5–6 , 11–14 )

Type material. Holotype: E MALAYSIA (Sarawak): ♂, six labels: " Mt. Matang , / W. Sarawak / G.E. Bryant / XII. 1913 " [white with median yellow line, printed, with the date handwritten], "Type" [circular white label with broad red margin, printed], " G. Bryant Coll. / 1919-147" [white, printed], " Cephennomicrus / auriculatus m. / Cl. Besuchet / det. IX 1957 " [white, handwritten and printed], " CEPHENNOMICRUS / matangensis m. / P. Jałoszyński, 2019 / HOLOTYPUS " [red, printed] ( NHM) . Paratypes: 4 ♀♀, same data as for holotype but each with circular "Para- / type" label with yellow margin ( NHM) .

Diagnosis. BL 0.95–1.00 mm; body covered with moderately dense, relatively long setae, lacking macrosetae; head in males modified, with median tubercle between eyes accompanied anteriorly by a raised median area demarcated at each side by an oblique, sharply marked ridge, additionally area behind each supraantennal tubercle forms a distinct convexity; pronotum in both sexes (in females slightly less distinctly) with a deep impression running along each lateral margin, mesally demarcated from pronotal disc by a sharp ridge; pronotal base with two pairs of tiny antebasal pits, inner pair connected by shallow and diffuse transverse groove; aedeagus in ventral view with apical margin bearing a deep and broad subtriangular emargination, endophallus with asymmetrical median subapical tubular component flanked by a pair of lightly sclerotized, elongate structures.

Description. Body of male ( Fig. 2 ) moderately stout, strongly convex, uniformly and moderately dark brown, except for appendages, which are slightly lighter; setae yellowish; BL 1.00 mm.

Head ( Figs 5–6 ) broadest at large, strongly convex and coarsely faceted eyes, HL 0.13 mm, HW 0.28 mm; vertex weakly convex and unmodified; frons with small transverse median tubercle and a raised area in front of tubercle, the latter convexity is demarcated laterally by sharply marked, oblique and anteriorly divergent ridges; supraantennal tubercles small and weakly elevated, but each accentuated by a small posterior convexity, near mesal margin of each eye. Punctures on vertex small but distinct, sparsely distributed, frons in front of median tubercle impunctate; setae on punctate areas short, sparse and nearly recumbent. Antennae slender, with indistinctly delimited trimerous club, AnL 0.48 mm, antennomeres I–II elongate, III–VI each about as long as broad, VII–IX each elongate, X about as long as broad, XI slightly shorter than IX–X combined, about twice as long as broad.

Pronotum ( Fig. 6 ) subtrapezoidal, broadest near anterior third; PL 0.30 mm, PW 0.38 mm; anterior margin broadly rounded; lateral margins indistinctly microserrate, in posterior 2/3 nearly straight and strongly convergent toward obtuse-angled hind corners; posterior margin very shallowly bisinuate. Pronotum with a distinct, sharply bordered impression along each lateral margin, base with two pairs of tiny lateral pits, inner pair connected by distinct, although shallow and diffuse transverse groove. Punctures on pronotum small but sharply marked, moderately dense, lateral impressions and area behind antebasal transverse groove impunctate; setae moderately long and dense, suberect.

Elytra together oval, broadest near anterior third; EL 0.58 mm, EW 0.45 mm, EI 1.28; humeral calli distinct; subhumeral lines very short, inconspicuous; elytral apices separately rounded. Punctures on elytra less distinct than those on pronotum, inconspicuous; setae similar to those on pronotum

Legs moderately long and slender, unmodified.

Aedeagus ( Figs 11–14 ) stout; AeL 0.18 mm; median lobe in ventral view with apical dorsal plate deeply emar- ginated distally; dorsal plate (forming dorsal wall of aedeagus) with its apical margin subtriangular; endophallus with asymmetrical median subapical tubular component flanked by a pair of lightly sclerotized, elongate structures; parameres slender, each with one long and one short apical setae, additionally with one long subapical seta.

Female. Externally similar to male, but with unmodified head, slightly shorter antennae in relation to body length and distinctly stouter elytra. BL 0.95–0.99 mm (mean 0.97 mm); HL 0.10–0.13 mm (mean 0.12 mm), HW 0.28 mm, AnL 0.43–0.48 mm (mean 0.44 mm); PL 0.30 mm, PW 0.40 mm; EL 0.55–0.58 mm (mean 0.56 mm), EW 0.48–0.50 mm (mean 0.48 mm), EI 1.10–1.21.

Distribution. East Malaysia: Borneo, western Sarawak.

Etymology. Locotypical, after Mt. Matang.

Remarks. This species is unique in having deep and broad impressions along lateral pronotal margins. The only Cephennomicrus species with a modified pronotum known so far was the Australian C. pronotalis Jałoszyński, 2018 , which, however, has broad and sharply demarcated lateral impressions not on entire length, but only near anterior pronotal corners, and a clearly different modification of the head in males.

Figures

FIGURES 1–6. Dorsal habitus of holotypes (1–4), head in dorsofrontal view (5), head and pronotum in dorsal view (6). Ce- phennococcus penangensis sp. n. (1); Cephennomicrus matangensis sp. n. (2, 5–6); Cephennomicrus selangorensis sp. n. (3); Trurlia nova sp. n. (4). Abbreviations: abg, antebasal groove; abp, antebasal pit.

FIGURES 7–14. Aedeagus in ventral (7, 9, 11, 13) and lateral (8, 10, 12, 14) views. Cephenococcus penangensis sp. n. (7–10); Cephennomicrus matangensis sp. n. (11–14).