Paraneseuthia spinipes, Jałoszyński, 2024

Jałoszyński, Paweł, 2024, Two new species of Eutheiini in Taiwan (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 5447 (4), pp. 591-599 : 595-596

Paraneseuthia spinipes sp. n.

( Figs 2–3 , 9–12 , 14 )

Type material. Holotype: TAIWAN: ♁, three labels: “ 10.IV.2007 leg. S. Vit / Rd.no. 23, km.14.5. / Hualien Co .. / TAIWAN merid. / mount. frst. litter / (alt. ± 700 m.)” [white, printed], “ Coll. S. Vit / MHNG - 2021” [white, printed], “ PARANESEUTHIA / spinipes m. / det. P. Jałoszyński, 2024 / HOLOTYPUS” [red, printed] ( MHNG).

Diagnosis. Profemur in male with tooth-like ventral projection in proximal third; protibia in male unmodified; aedeagus heavily sclerotized, in ventral view its subtriangular apical region with broadly rounded distal margin and sinuate lateral margins, ostium with two large oval structures partly exposed in ventral view, lateral margins of median lobe in subapical region with numerous dense setae.

Description. BL 1.18 mm. Body of male ( Fig. 2 ) elongate and moderately convex, moderately dark brown, legs and antennae slightly lighter, setae yellowish.

Head broadest at large, strongly convex oval eyes, HL 0.13 mm, HW 0.25 mm; vertex and frons confluent and evenly weakly convex; supraantennal tubercles small but distinct. Punctures on head dorsum inconspicuous; setae short, sparse and suberect. Antennae slender with distinctly delimited trimerous clubs, AnL 0.45 mm, antennomeres 1–2 elongate, 3 indistinctly transverse, 4–7 each about as long as broad, 8–10 each distinctly transverse, 11 slightly broader than 10, about as long as 9–10 together, about 1.8 × as long as broad.

Pronotum broadest near anterior third (in Fig. 2 slightly tilted anteroventrally, not shown in strictly dorsal view), PL 0.33 mm, PW 0.35 mm.Anterior and lateral margins rounded and posterior margin nearly straight, lateral margins distinctly narrowing toward obtuse-angled and blunt posterior corners; pronotal base with a transverse row of three distinct pits. Punctures on pronotal disc fine and inconspicuous; setae moderately long, sparse and suberect.

Elytra oval, broadest slightly in front of middle, evenly convex; EL 0.63 mm, EW 0.48 mm, EI 1.32; humeral calli distinct but small, basal impressions indistinct; apices separately rounded. Punctures on elytra as fine and inconspicuous as those on pronotum and head; setae moderately long and dense, weakly suberect. Hind wings well developed.

Metaventrite unmodified, weakly convex.

Pygidium with punctures as unremarkable as those on elytra.

Legs moderately long and slender; profemur ( Fig. 3 ) with small and pointed ventral tooth near proximal third; protibia unmodified.

Aedeagus ( Figs 9–12 ) fusiform, AeL 0.25 mm; median lobe in ventral view broadest slightly proximally to middle, with large subtriangular apical region, distal margin broadly rounded, lateral margins in subapical region sinuate; endophallus with two large oval lobes largely projecting from ventral subapical ostium; lateral margins in subapical region with dense setae of various lengths; parameres slender, each with one apical seta.

Female. Not known.

Distribution. Southeastern Taiwan ( Fig. 14 ).

Etymology. The adjective spinipes refers to the tooth-like profemoral projection.

Remarks. Paraneseuthia spinipes is the only known species of this genus with males bearing a tooth on the profemur and rows of dense setae in the subapical region of the aedeagus. Some Far Eastern Palaearctic species have modified protibiae, and P. spinosa Jałoszyński, 2010b (Sumatra) and P. loebli Jałoszyński, 2015 ( India) have a tooth-like projection on the protrochanter, but none of the previously known species has any profemoral modifications. Moreover, in most world species, the median lobe is devoid of any setae, and only in P. tanimbariana Jałoszyński, 2019b (Tanimbar Island of Indonesia), P. dilatifurculata Jałoszyński, 2013c , P. angustifurculata Jałoszyński, 2013c and P. bernierana Jałoszyński, 2013c (all three from Australia) one pair of long setae can be found on lateral margins of the subapical region of the aedeagus. All species of Paraneseuthia that occur in Japan and the Russian Far East have a different form of the aedeagus, and they all seem to belong to a monophyletic lineage clearly differing from SE Asian, New Guinean and Australian species (see Jałoszyński (2011b) for preliminary phylogeny and discussion). Interestingly, the Taiwanese P. spinipes , although geographically close to the 'Japanese group' of species, is not similar to the Ryukyuan and Japanese mainland congeners. The unique aedeagus is not similar to any copulatory organs known so far in this genus, and it is difficult to hypothesize whether P. spinipes is derived from SE Asian or from Japanese-Russian groups of species.

Figures

FIGURE 14. Distribution of nominal Paraneseuthia species in Taiwan, Japan and Russian Far East.

FIGURES 1–3. Eutheia clepsydra sp. n. (1), and Paraneseuthia spinipes sp. n. (2, 3). Dorsal habitus of males (1, 2); fore leg (3).

FIGURES 4–12. Eutheia clepsydra sp. n. (4–8), and Paraneseuthia spinipes sp. n. (9–12). Aedeagus of holotype (4–5, 7–12) and paratype (6) in ventral (4, 6, 7, 9, 11) and lateral (5, 8, 10, 12) views.