Cephennomicrus manusianus, Jałoszyński, Paweł, 2017

Jałoszyński, Paweł, 2017, First record of Cephenniitae in the Bismarck Archipelago, Papua New Guinea, with description of new species of Cephennodes and Cephennomicrus of Mussau and Manus Islands (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4268 (3), pp. 427-432 : 429-431

Cephennomicrus manusianus sp. n.

( Figs 4–6 , 7–9 )

Material studied. Holotype: male ( PAPUA NEW GUINEA, MANUS PROVINCE, MANUS ISLAND): two labels: "Bismarck Isl . Manus / Lorengau Berl. nr. 62 / 22. June 1962 / Noona Dan Exp. 61-62" [white, printed and handwritten], " CEPHENNOMICRUS / manusianus m. / P. Jałoszyński, 2017 / HOLOTYPUS " [red, printed] ( ZMUC) .

Diagnosis. Male: BL <0.80 mm; head unmodified; dorsum of head, prothorax and elytra with fine, very short and recumbent setae, lacking macrosetae; antennae with distinctly delimited club composed of two terminal antennomeres; pronotum with two pairs of lateral antebasal pits, inner pair connected by narrow transverse groove; aedeagus strongly elongate, with thick and long, unlooped flagellum.

Description. Body of male ( Fig. 4 ) elongate, strongly convex, BL 0.76 mm; pigmentation uniformly brown, appendages slightly lighter, vestiture of setae yellowish.

Head declined, broadest at eyes, HL 0.09 mm, HW 0.20 mm; vertex and frons confluent and convex; supraantennal tubercles small and feebly elevated. Eyes large, distinctly projecting laterally from the head silhouette, coarsely faceted. Punctures on vertex and frons small and moderately sharply marked, separated by distances slightly shorter than diameters of punctures; setae barely discernible under magnification 80 ×, very short, dense, recumbent. Antennae slender with abruptly broadened club composed of two antennomeres, AnL 0.38 mm; antennomeres I–II strongly elongate, III–VII slightly elongate, VIII about as long as broad, IX slightly elongate, X strongly broadened, slightly transverse, XI slightly longer than X and nearly equally broad, indistinctly longer than broad, with rounded apex lacking subapical constriction.

Pronotum broadest near posterior third, PL 0.25 mm, PW 0.33 mm; anterior margin weakly arcuate, lateral margins strongly rounded in anterior half, nearly straight in posterior third and distinctly convergent posteriorly; posterior pronotal corners slightly obtuse-angled and blunt; posterior margin weakly arcuate with indistinct flattening in front of scutellum; pronotal base with two lateral pairs of small, circular, distinct antebasal pits, inner pair connected by narrow transverse groove, pits separated from posterior pronotal margin by distance subequal to diameters of pits. Punctures on pronotal disc fine, superficial, inconspicuous; setae moderately dense, longer than those on vertex but still very short, recumbent.

Elytra oval and evenly convex, as convex as pronotum, broadest near anterior third, EL 0.43 mm, EW 0.40 mm, EI 1.06; humeral calli distinct, elongate. Punctures on elytral disc fine and inconspicuous; setae short, moderately dense and recumbent. Hind wings about twice as long as elytra.

Mesoscutellum with distinct median pit at base.

Legs moderately long and slender, unmodified.

Aedeagus ( Figs 5–6 ) large, AeL 0.28 mm; strongly elongate, narrowing from base to apex; ventral diaphragm nearly circular and strongly shifted toward base of median lobe; endophallus with long and thick flagellum; parameres long and slender, each with two apical setae.

Female. Unknown.

Distribution ( Figs 7–9 ). Manus Island of Bismarck Archipelago.

Etymology. Locotypical, for Manus Island.

Remarks. Cephennomicrus manusianus is similar to the Papuan species C. gumnos ; they share a similar body shape, fine and recumbent vestiture of setae, the pronotal antebasal pits located very close to the posterior pronotal margin and strongly elongate aedeagus. Cephennomicrus manusianus is much smaller than C. gumnos (BL 0.76 mm vs. 1.18–1.19 mm) and slightly more slender; its body is less glossy and lacks macrosetae, which in C. gumnos are distributed on sides of pronotum and elytra. Moreover, the endophallus of C. gumnos lacks long and sclerotized flagellum, present in C. manusianus . Other species of Cephennomicrus with similarly elongate aedeagi are C. lasios Jałoszyński, 2010c (Luzon) , C. santubongensis Jałoszyński, 2015 ( Sarawak) , and the taiwanensis species group ( Taiwan and Japan) ( Jałoszyński 2004, 2009c). However, the remarkably thick and long flagellum lacking loops is characteristic only of C. manusianus , in all remaining species with long and slender aedeagi the flagellum is either much thinner and looped, or absent.

Figures

FIGURES 1 – 6. Cephennodes mussauinsularis sp. n. (1 – 3) and Cephennomicrus manusianus sp. n. (4 – 6). Male holotype in dorsal view (1, 4); aedeagus in ventral (2, 5) and lateral (3, 6) views.

FIGURES 7 – 10. Distribution of Cephenniini in Bismarck Archipelago (7 – 8); distribution of Cephennomicrus manusianus sp. n. within Manus Island (9) and Cephennodes mussauinsularis sp. n. within Mussau Island (10).