Penicillidmus lavongai, Jałoszyński, Paweł, 2017

Jałoszyński, Paweł, 2017, Discovery of Penicillidmus in the Bismarck Archipelago, Papua New Guinea, with description of a new species from Lavongai (New Hanover) Island (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4254 (3), pp. 391-395 : 392-395

Penicillidmus lavongai sp. n.

( Figs 1–12 )

Material studied. Holotype: male ( PAPUA NEW GUINEA, NEW IRELAND PROVINCE, LAVONGAI ISLAND): two labels: " Bismarck Islands Berl. / Lavongai , Banatam nr. / 20. March 1962 15 / Noona Dan Exp. 61-62", " PENICILLIDMUS / lavongai m. / P. Jałoszyński, 2017 / HOLOTYPUS " [red, printed] ( ZMUC) .

Diagnosis. Male: BL> 1 mm; pronotum broader than long; sides of pronotum with fine and incomplete but distinct lateral carina; insertion site of pronotal setal brush angulate in dorsal view; aedeagus in ventral view with a pair of elongate sclerites in apical half, sclerites connected distally and divergent proximally.

Description. Body of male ( Figs 1–2 ) elongate but moderately slender, strongly convex, with short and robust appendages, BL 1.13 mm; cuticle glossy, pigmentation uniformly reddish-brown, appendages slightly lighter, vestiture of setae yellowish.

Head ( Figs 1–2 , 4–5 ) strongly declined, broadest at eyes, HL 0.28 mm, HW 0.26 mm; tempora in lateral view ( Fig. 5 ) slightly shorter than eyes, in dorsal view ( Fig. 4 ) weakly rounded and weakly convergent posteriorly; vertex and frons confluent and weakly convex; supraantennal tubercles small and feebly elevated. Eyes large, emarginate posteriorly, each composed of 20 ommatidia, distinctly projecting laterally from the head silhouette. Punctures on vertex and frons fine and superficial; setae short and dense, nearly recumbent. Antennae slender but short, AnL 0.33 mm; antennomeres I–II elongate, III–VI each slightly transverse, VII–VIII about as long as broad, IX slightly transverse, X strongly transverse, XI distinctly narrower than X, indistinctly longer than broad, with rounded apex.

Pronotum ( Figs 1–5 ) broadest near posterior third, PL 0.28 mm, PW 0.38 mm; anterior margin weakly arcuate, lateral margins rounded in anterior half, angulate at insertions of lateral setal brushes and behind them slightly concave and strongly convergent posteriorly; posterior pronotal corners obtuse-angled and blunt; posterior margin indistinctly bisinuate; base with two pairs of round, distinct pits, inner pair connected by indistinct transverse groove. Sides of pronotum with fine but distinct lateral carinae extending from setal brushes to anterior third of pronotum, carinae shallowly undulant. Punctures on pronotal disc fine, superficial, inconspicuous; setae dense, longer than those on vertex and suberect.

Elytra ( Figs 1–3 ) oval, as convex as pronotum, broadest near middle, EL 0.58 mm, EW 0.45 mm, EI 1.28; basal impressions short; elytral apices separately rounded. Punctures on elytral disc very fine and inconspicuous; setae short, moderately dense and suberect, additionally sides of elytra with sparse, long and erect setae. Hind wings long, functional.

Legs moderately long and slender, unmodified.

Aedeagus ( Figs 6–9 ) small, AeL 0.15 mm; elongate, apex of median lobe in lateral view slightly curved ventrally, in ventral view subtriangular and blunt; endophallus with two rod-like sclerites in subapical region, sclerites connected distally and divergent proximally; parameres short, each with one long apical seta.

Female. Unknown.

Distribution ( Figs 10–11 ). Lavongai (New Hanover) Island of Bismarck Archipelago.

Etymology. Locotypical, after the island where this species occurs (the specific name is a noun in apposition).

Remarks. Penicillidmus lavongai is distinctly larger than both previously known Australian species (BL 1.13 mm vs. 0.83¯ 0.86 mm); additionally it has a distinctly transverse pronotum (subquadrate in P. masseyensis and P. unicolor ). Its aedeagus is very similar to those of the two Australian species, both in the general shape and endophallic structures. The two rod-like sclerites in P. lavongai , however, are connected distally and located in the apical half of the median lobe, whereas in P. masseyensis they are subparallel and not connected, and in P. unicolor the sclerites, although similarly shaped, are separated distally and located in the basal half of the aedeagus.

A female similar to the male of P. lavongai , but with shorter elytra, and most likely representing a different species, was also found among the Noona Dan Expedition material in ZMUC. It comes from Manus Island, the largest island of the Admiralty Islands, which are a part of the Bismarck Archipelago.

Penicillidmus is now known to occur in north-eastern Australia (Cape York, Queensland) and the Bismarck Archipelago (islands Lavongai (known also as New Hanover) , New Ireland Province, and Manus , Manus Province of Papua New Guinea) ( Fig. 12 ). This distribution suggests that Penicillidmus should also be present on New Guinea .

Figures

FIGURES 1 – 2. Penicillidmus lavongai sp. n., male holotype; dorsal (1) and lateral (2) habitus.

FIGURES 3 – 5. Penicillidmus lavongai sp. n., male holotype; body outline in dorsal view (3); head and prothorax in anterodorsal (4) and lateral (5) views.

FIGURES 6 – 9. Penicillidmus lavongai sp. n., male holotype; aedeagus in ventral (6, 8) and lateral (7, 9) views.

FIGURES 10 – 12. Distribution of Penicillidmus lavongai sp. n. (10 – 11); distribution of all species of Penicillidmus (12), dark circles represent nominal species, empty circles represent undescribed species known only from females.