Nipponophloeostiba longilobata, Shavrin, 2020

Shavrin, Alexey V., 2020, New species and records of Paraphloeostiba Steel, 1960 from China and Laos and descriptions of four new species of related genera (Coleoptera: Staphylinidae Omaliinae: Omaliini), Zootaxa 4890 (3), pp. 301-329 : 317-319

Nipponophloeostiba longilobata sp.n.

( Figs. 39–42 )

Type material examined: Holotype Ƌ (dissected; right elytron slightly damaged): ‘LAOS—Xieng Khouang, | 30 km NE Phonsavan , | Phou Sane Mt. , 19°38.2’N, | 103°20.2’E, 1420 m, 10– | 30.V.2009, leg. Brancucci’ <printed>, ‘ HOLOTYPE | Nipponophloeostiba | longilobata sp. n. | Shavrin A. V. des. 2020’ <red, printed> ( NHMB).

Description. Measurements: HW: 0.38; HL: 0.25; AL: 0.40; OL: 0.09; TM: 0.07; PL: 0.32; PW: 0.40; ESL: 0.41; EW: 0.48; AW: 0.43; MTbL: 0.22; MTrL: 0.12 (MTrL 1–4: 0.05; MTrL 5: 0.07); AedL: 0.33; TL: 2.07.

Head, antennomeres 6–11, pronotum, scutellum, parascutellar portion of elytra, and abdomen reddish-brown; elytra yellow-brown; mouthparts, antennomeres 1–5, intersegmental membranes between abdominal tergites, and legs yellow. Head with sparse and fine punctation, denser in middle portion; neck without visible punctures; pronotum with sparse, fine punctation, similar to that of head, sparser in middle, mediobasal portion without punctures; scutellum without punctation; elytra with fine punctation, denser than that on pronotum, deeper along suture, and indistinct in apical third; abdomen with very indistinct, sparse and fine punctures. Head with dense, relatively coarse microsculpture: transverse in apical and longitudinal in middle and lateral portions; neck with transverse meshes, with wide, impunctate middle portion; pronotum with dense, longitudinal microreticulation, coarser than that of head; elytra with longitudinal, regular sculpture, similar to that of pronotum, but slightly coarser; abdomen with distinct, dense, and transverse microsculpture, denser and coarser on abdominal tergite VII.

Head wide, 1.5 times as broad as long, with deep, moderately long, straight anteocellar foveae extending to level of apical third of eyes; middle portion between anteocellar foveae with distinct, transverse impression; basal margin of head straight; posterior portions of head between ocelli and temples with narrow, straight carina, almost reaching posterior margin of eye; postantennal impressions indistinct; temples (postocular parts) long, parallelsided, not expanded laterad, slightly shorter than longitudinal length of eyes. Eyes large, moderately convex. Ocelli small, located very close to posterior constriction, distance between ocelli about one and a half times as long as distance between ocellus and posterior margin of eye. Neck separated from head by narrow, deep constriction. Maxillary palpi long; preapical palpomere slightly longer than wide; apical palpomere narrow, from basal portion gradually narrowing apicad, about 1.4 times as long as preceding palpomere. Antennae reaching apical third of pronotum when reclined; basal antennomere wide, about 1.6 times as long as wide, antennomere 2 small, slightly longer than wide, 3 narrow, about as long as 2, 4–5 small, transverse, about as broad as 3, 6–10 strongly transverse, significantly wider than 5, 7–10 slightly wider than 6, apical antennomere about as broad as, and about twice as long as 10.

Pronotum subtrapezoidal, slightly wider than long and wider than head, widest in apical third, from about middle strongly narrowed posteriad; latero-basal margins slightly concave in front of rounded posterior angles; anterior angles widely rounded; anterior margin slightly concave in middle, with two very small, convex tubercles at level of lateral margins of neck; posterior margin rounded; median part with longitudinal narrow band; lateral portions narrowly bordered and flattened at margins, laterobasal portions distinctly impressed.

Elytra moderately short, slightly wider than long, 1.2 times as long as pronotum, relatively parallel-sided, with slightly concave lateral margins in middle; posterior margin slightly rounded. Wings fully developed.

Metatarsus 1.8 times as long as metatibia; apical metatarsomere distinctly longer than remaining four combined tarsomeres.

Abdomen parallel-sided, narrower than combined width of elytra, with two small, round wing-folding patches in middle of abdominal tergite IV and indistinct palisade fringe at apical margin of tergite VII.

Male. Posterior margins of abdominal tergite VIII ( Fig. 41 ) and sternite VIII ( Fig. 42 ) indistinctly sinuate. Aedeagus long, with wide basal portion, gradually narrowed apically, and with moderately narrow, long median lobe ( Fig. 39 ); parameres wide, distinctly extending beyond apex of median lobe, distinctly widened toward apical portions, with five long apical, two preapical, four setae along inner edge, and several very small setae on middle surface of each paramere; internal sac with two long structures consisting of fine, small spines. Aedeagus laterally as in Fig. 40 .

Female unknown.

Comparative notes. Regarding t body size and the laterally not widened postocular parts of head, N. longilobata sp.n. is similar to N. thayeri Shavrin, 2020 , a species recently described from Sabah, Borneo, Malaysia ( Shavrin 2020). It differs from this species by paler coloration, slightly less prominent eyes, shorter elytra, a wider median lobe of the aedeagus and parameres, and the internal structures of the aedeagus. The shape of the median lobe is somewhat similar to N. verrucifera Watanabe, 1962 from Izu islands and Yaku-shima Island, Japan ( Watanabe 1962b, 1990), but the parameres of N. longilobata sp.n. are wider, with longer and more numerous apical setae. For additional details see the key to the species of Nipponophloeostiba below:

1 Postocular portions of head distinctly widened lateroposteriad, with short posterior carina not reaching posterior margin of eye. Aedeagus as illustrated by Watanabe (1990: figures 86–87). Head and pronotum reddish-brown, elytra and abdomen yellowbrown. Body larger: 2.30–2.70 mm. Japan........................................................ N. verrucifera

- Postocular portions of head not widened lateroposteriad, with long posterior carina reaching posterior margin of eye. Coloration different. Body smaller................................................................................. 2

2 Head as broad as pronotum. Elytra moderately long, significantly longer than pronotum. Median lobe and parameres narrow ( Shavrin 2020: figure 2). Body darker: head and abdomen brown, pronotum reddish-brown. Body length: 1.75–2.22 mm. Malaysia........................................................................................ N. thayeri

- Head slightly narrower than pronotum. Elytra short, slightly longer than pronotum. Median lobe and parameres moderately wide ( Fig. 39 ). Body paler: head, pronotum and abdomen reddish-brown, elytra yellow-brown, with darker parascutellar portion. Body length: 2.07 mm. Laos.............................................................. N. longilobata

Distribution. The new species is known only from the type locality in Phou Sane mountain range, northern Laos.

Bionomics. The specimen was collected on the wing, most likely with a Malaise trap, at an elevation of 1420 m a.s.l.

Etymology. The specific epithet is a combination of Latin adjective longus, - a, - um (long) and lobatus, - a, - um (lobed). It refers to elongate and narrow median lobe.

Figures

FIGURES 39–42.Aedeagus (Figs. 39–40) and abdominal segments (Figs. 41–42) of Nipponophloeostiba longilobata: 39—aedeagus, parameral view, 40—aedeagus, lateral view, 41—male tergite VIII (dorsal view), 42—male sternite VIII (ventral view). Scale bar: 0.1 mm.