Cephennomicrus triangularis, Jałoszyński, 2018

Jałoszyński, Paweł, 2018, Revision of Cephennomicrus of Australia (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4422 (2), pp. 151-183 : 159

Cephennomicrus triangularis sp. n.

( Figs 26–31 , 123 )

Type material. Holotype: AUSTRALIA (WESTERN AUSTRALIA): ♂, three labels: " 15.38S 125.15E WA / CALM Site 28/3 / 4 km W of / King Cascade / Jan. 1989 —N.McKenzie" [white, printed], "Berlesate / ANIC 1274 / closed forest / litter" [white, printed], " CEPHENNOMICRUS / triangularis m. / P. Jałoszyński, '18 / HOLOTYPUS " [red, printed] ( ANIC).

Diagnosis. BL 0.74 mm; body relatively slender, EI 1.21; antennomeres I–II distinctly elongate, III–V and VII indistinctly elongate, VI and VIII–X about as long as broad; antennal club trimerous and indistinctly delimited; inner pair of pronotal antebasal pits connected by a deep groove; frons in males modified, with a median elongate triangular elevation sharply demarcated laterally and anteriorly, but not posteriorly, elevation asetose; aedeagus slender, with distal portion of flagellum not coiled.

Description. Body of male ( Fig. 26 ) elongate, slender, uniformly light brown; setae on head, pronotum and elytra extremely short, dense and recumbent, barely discernible at magnification 80 ×. BL 0.74 mm.

Head ( Fig. 27 ) broadest at large, strongly convex and coarsely faceted eyes, HL 0.09 mm, HW 0.20 mm; vertex weakly convex; frons modified, with elongate median triangular elevation sharply demarcated laterally and anteriorly, but posteriorly confluent with vertex, frons at each side of elevation impressed, impressed area and elevation asetose; supraantennal tubercles weakly elevated. Punctures on vertex and sides of frons dense but very small and shallow, inconspicuous, elevation and impressed area impunctate. Antennae slender, with indistinctly delimited trimerous club, AnL 0.33 mm, antennomeres I–II distinctly elongate, III–V and VII only slightly longer than broad, VI and VIII–X each about as long as broad, XI about as long as IX and X combined, slightly less than twice as long as broad.

Pronotum subtrapezoidal, broadest near anterior fourth; PL 0.23 mm, PW 0.25 mm; anterior and posterior margins nearly straight, anterior corners broadly rounded, sides rounded in anterior third and nearly straight in posterior half, posterior corners strongly obtuse-angled and blunt; base with two lateral pairs of small but distinct pits, inner pair connected by a distinct transverse groove; lateral pronotal carinae indistinctly serrate. Punctures on pronotal disc very dense but very small and superficial, inconspicuous.

Elytra oval, broadest distinctly anterior to middle; EL 0.43 mm, EW 0.35 mm, EI 1.21; humeral calli distinct; apices separately rounded. Punctures similar to those on pronotal disc.

Legs moderately long and slender, unmodified.

Aedeagus ( Figs 22–25 ) strongly elongate; AeL 0.18 mm; median lobe in ventral view with elongate proximal capsular part and much shorter, sharply delimited distal part, which is subtrapezoidal in proximal half and then broadens distad, with apical margin nearly straight; diaphragm distinct, circular, sub-basally on ventral wall; flagellum in subapical region poorly visible, not coiled; each paramere with one long apical and two short subapical setae.

Female. Unknown.

Distribution ( Fig. 123 ). Western Australia.

Etymology. The name triangularis refers to the triangular median elevation on the frons of males.

Remarks. The triangular and sharply delimited elevation on the frons of males is unique for this species; also the slender aedeagus with distinctly constricted distal portion of the median lobe is conspicuous and not possible to confuse with copulatory organs of any other species of Cephennomicrus .

Figures

FIGURE 123. Distribution of Cephennomicrus in Australia; white circles denote nominal species, solid black circles denote undescribed species known from females only (distribution of undescribed species known from the same localities as nominal ones is omitted).

FIGURES 26–31. Cephennomicrus triangularis sp. n. Dorsal habitus (26); head of male in dorsal view (27); aedeagus in ventral (28, 30) and lateral (29, 31) views.

FIGURES 13–25. Cephennomicrus monteithi sp. n. (13–19) and C. pronotalis sp. n. (20–25). Dorsal habitus (13, 20); head of male in dorsal view (14, 21); right mandible of male in dorsal view (15); aedeagus in ventral (16, 18, 22, 24) and lateral (17, 19, 23, 25) views.