Paraneseuthia luzonica, Jałoszyński, 2019

Jałoszyński, Paweł, 2019, Four new Australo-Oriental species of Paraneseuthia (Coleoptera: Staphylinidae: Scydmaeninae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 59 (2), pp. 491-498 : 492-493

Paraneseuthia luzonica sp. nov.

( Figs 1 , 5–6 )

Type material. HOLOTYPE: ♂, PHILIPPINES: three labels: ʻ(PHILIPPINES) / Mt. Maquiling / alt. 400 m / Lagina Prov. / Luzon, 12. IX. / 1985, K. Ishikawa’ [white, printed], ʻTullgren sample / of leaf litter’ [white, printed], ʻ PARANESEUTHIA / luzonica / det. P. Jałoszyński, 2019 / HOLOTYPUS’ [red, printed] ( EUMJ). PARATYPES: 3 ♂♂ 3 ♀♀, same data as for holotype, except for yellow ʻPARATYPUS’ label ( EUMJ, cPJ).

Diagnosis. Body strongly convex; frons and vertex in both sexes with median, slightly elongate, impunctate and glossy area demarcated by lateral rows of 2–3 small but distinct punctures, several similar punctures demarcate this area also anteriorly, forming an arcuate row or transverse group of punctures between antennal insertions; pronotum lacking transverse antebasal groove; punctures on elytra much more distinct than those on pronotum; aedeagus with median lobe broadest in submedian region, with strongly asymmetrical, subtriangular apex, lacking lateral projections, with a pair of asymmetrical, elongate sclerites partly protruding from ostium, one weakly curved, the other nearly U-shaped; parameres slender, each with one apical seta.

Description. Male. Body ( Fig. 1 ) suboval, strongly convex; BL 0.94–0.99 mm (mean 0.96 mm); cuticle glossy, moderately dark reddish-brown, appendages indistinctly lighter, setae light brown.

Head broadest at eyes, HL 0.11–0.13 mm (mean 0.12 mm), HW 0.20 mm; vertex and frons confluent, their elongate, suboval median portions demarcated anteriorly and laterally by several deep punctures (2–4 on each side and 3 or more anteriorly, anterior punctures form arcuate transverse row, irregular oval or nearly triangle). Supraantennal tubercles weakly elevated. Median area of frons and vertex virtually impunctate and glossy; punctures on sides fine and inconspicuous; setae very short, suberect, sparse. Eyes large, bean-shaped, strongly convex. Antennae short, AnL 0.38–0.39 mm (mean 0.38 mm); antennomeres 1–2 each elongate, 3–8 each about as long as broad, 9 weakly transverse, 10 distinctly, but not strongly transverse, 11 distinctly broader than 10, about 1.7× as long as broad.

Pronotum in dorsal view subtrapezoidal, rounded, broadest slightly behind middle or near posterior third, PL 0.26–0.30 mm (mean 0.28 mm), PW 0.33–0.35 mm (mean 0.33 mm); anterior margin broadly rounded, lateral margins rounded, more strongly so in anterior third, weakly in posterior fourth; posterior pronotal corners obtuse-angled and blunt; posterior margin nearly straight; lateral antebasal impressions distinct, subtriangular, each accompanied by small and shallow but distinct pit closer to lateral margin than to middle, pits not connected by groove. Punctures on pronotal disc very shallow and small but dense, those at middle separated by distances shorter than diameters of punctures; setae short, sparse, suberect.

Elytra together oval, broadest near anterior third, EL 0.55–0.58 mm (mean 0.56 mm), EW 0.45–0.46 mm (mean 0.45 mm), EI 1.22–1.28; humeral calli small, elongate, elytral apices separately, broadly rounded. Punctures much larger and deeper than those on pronotum, those in anterior half separated by spaces subequal to diameters of punctures, punctures reduce in diameter and depth toward sides and apex; setae sparse, suberect, slightly longer than those on pronotum.

Legs moderately long and slender; unmodified, protibiae straight.

Aedeagus ( Figs 5–6 ) bottle-shaped, moderately stout, AeL 0.23 mm, median lobe in ventral view broadest in submedian region, with rapidly narrowed, strongly asymmetrical apical portion, which is trapezoidal with oblique distal margin; endophallus with pair of dark, asymmetrical elongate sclerites, one slender and only weakly curved, other nearly U-shaped; parameres slender, in lateral view weakly curved, each with one apical seta.

Female similar to male, with on average slightly higher EI. BL 0.89–0.93 mm (mean 0.91 mm); HL 0.10 mm, HW 0.19–0.20 mm (mean 0.20 mm), AnL 0.38 mm; PL 0.26–0.28 mm (mean 0.27 mm), PW 0.33 mm; EL 0.53–0.56 mm (mean 0.54 mm), EW 0.40–0.43 mm (mean 0.42 mm), EI 1.29–1.31.

Etymology. After the island of Luzon; adjective.

Distribution. The Philippines, southern Luzon, western part of Laguna Province.

Remarks. The aedeagus of P. luzonica does not show close similarities to male copulatory organs of any other known congener. The general bottle-like shape of the median lobe, with a rapidly tapered apical region, remotely resembles the aedeagus of P. peckorum Franz, 1986 ( Fiji) . However, in the latter species the apex of the median lobe is symmetrical, in contrast to the strong asymmetry visible in the same region in P. luzonica . Otherwise, the Philippine species resembles other SE Asian congeners in having a strongly convex, relatively stout body and a slightly modified frons. Consequently, examination of the unique aedeagus is necessary for unambiguous identification.

Figures

Figs 1–4. Dorsal habitus of male holotypes. 1 – Paraneseuthia luzonica sp. nov.; 2 – P. kaibesariana sp. nov.; 3 – P. tanimbariana sp. nov.; 4 – P. morobensis sp. nov.

Figs 5–12. Aedeagus in ventral (5, 7, 9, 11) and lateral (6, 8, 10, 12) views. 5–6 – Paraneseuthia luzonica sp. nov.; 7–8 – P. kaibesariana sp. nov.; 9–10 – P. tanimbariana sp. nov.; 11–12 – P. morobensis sp. nov.