Cephennodes (s. str.) mussauinsularis, 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 : 428-429

Cephennodes (s. str.) mussauinsularis sp. n.

( Figs 1–3 , 7–8, 10 )

Material studied. Holotype: male ( PAPUA NEW GUINEA, NEW IRELAND PROVINCE, MUSSAU ISLAND): two labels: " Bismarck Isl. Mussau / Talumalaus Berl. nr. 9 / 2.Februar1962 / Noona Dan Exp. 61-62" [white, printed and handwritten], " CEPHENNODES (s. str.) / mussauinsularis m. / P. Jałoszyński, 2017 / HOLOTYPUS " [red, printed] ( ZMUC) .

Diagnosis. Male: BL between 1.1 and 1.2 mm; vertex with weakly elevated and diffuse median tubercle demarcated from frons by shallow impression visible in lateral view; pronotum with lateral carinae broadly separated from lateral margins and obliterated in anterior fourth; distance between antebasal pronotal pit and lateral pronotal carina slightly shorter than that between carina and lateral pronotal margin; elytra broadest at humeral denticles and strongly narrowing posteriorly; subhumeral lines rudimentary, weakly marked and only as long as about 1/10 of EL; postmesocoxal impressions very short, not reaching half of metaventrite; aedeagus simonis form, in ventral view with subtriangular and rounded apex of median lobe and short left apical projection, which has nearly straight apical margin slightly oblique in relation to the long axis of aedeagus.

Description. Body of male ( Fig. 1 ) stout, moderately convex with flattened dorsum, BL 1.13 mm; pigmentation uniformly brown, vestiture of setae yellowish.

Head strongly declined, broadest at eyes, HL 0.25 mm, HW 0.28 mm; vertex slightly bulging at middle, elevated area diffuse and demarcated from frons by shallow impression well visible in lateral view; supraantennal tubercles distinct but small and feebly elevated. Eyes small, strongly projecting laterally and coarsely faceted. Punctures on vertex and frons fine and superficial; setae short and sparse, suberect. Antennae short with strongly thickened three terminal antennomeres, AnL 0.45 mm; antennomeres I–II elongate, III about as long as broad, IV– VI each slightly elongate, VII distinctly elongate, VIII–IX slightly transverse, X distinctly transverse, XI indistinctly longer than IX–X combined, broader than X, about 1.7 times as long as broad, with subtriangular apex.

Pronotum broadest at base, PL 0.33 mm, PW 0.51 mm; anterior margin weakly arcuate, lateral margins strongly rounded in anterior half and much less so in posterior third; posterior corners sharp-angled and acute; posterior margin distinctly bisinuate; lateral carinae fine but distinct, distant from lateral pronotal margins, extending from posterior pronotal margin to nearly 3/4 of PL; antebasal pits shallow and diffuse, distance between each pit and pronotal margin about twice as wide as that between pit and posterior pronotal margin. Punctures on pronotal disc very fine and shallow but dense, those between lateral margins and lateral carinae slightly more distinct and coarser; setae dense, short and suberect.

Elytra drop-shaped, as convex as pronotum, broadest at base and strongly narrowing posteriorly, EL 0.55 mm, EW 0.50 mm, EI 1.10; subhumeral lines rudimentary, diffuse and only as long as about 1/10 of EL; basal elytral foveae located distinctly closer to lateral margins of mesoscutellum than to subhumeral lines; elytral apices separately rounded. Punctures on elytral disc similar to those on pronotum but slightly more distinct; setae short, moderately dense and suberect. Hind wings about twice as long as elytra.

Legs moderately long and slender, unmodified.

Metaventrite with short postmesocoxal impressions not reaching half length of ventrite.

Aedeagus ( Figs 2–3 ) simonis form, AeL 0.13 mm; elongate, median lobe drop-shaped with subtriangular and blunt apex; apical group of projections in ventral view composed of short left projection forming hook that is curved dorsally, and long right projection in lateral view slightly curved ventrally; parameres slender, each with two or three setae.

Female. Unknown.

Distribution ( Figs 7–8, 10 ). Mussau Island of Bismarck Archipelago.

Etymology. Locotypical, after Mussau Island.

Remarks. The only species of Cephennodes s. str. with the elytra broadest at base and strongly narrowing posteriorly, as those in C. mussauinsularis , is C. leai ( Jałoszyński, 2008b) from Australia. In all remaining species of Cephennodes the elytra are broadest behind the humeri, and consequently there is a shallow but discernible constriction between the pronotum and elytra. In C. mussauinsularis and C. leai (and several undescribed species from Australia) the sides of pronotum and elytra are confluent and the body is not constricted. Cephennodes mussauinsularis can be distinguished from C. leai on the basis of the apical aedeagal projections; in the ventral view the left projection in the species of Mussau Island is much shorter than the right projection; in C. leai the left projection is longer and has a different shape (illustrated in Jałoszyński (2008b)). The only previously known species of Cephennodes from Papua New Guinea, C. papuanus , is distinctly larger than C. mussauinsularis (BL 1.52 mm vs. 1.13 mm) and has the elytra stouter, less narrowed posteriorly, broadly rounded at apices, with much longer and distinct subhumeral lines ( Jałoszyński 2008a).

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).