Phloeostiba mamasa, Shavrin, 2023

Shavrin, Alexey V., 2023, Two new species and a new record of Omaliini McLeay, 1825 (Coleoptera: Staphylinidae: Omaliinae) from Indonesia, Zootaxa 5258 (2), pp. 245-250 : 248-250

Phloeostiba mamasa sp. n.

( Figs 2 , 7–10 )

Type material. HOLOTYPE: ♂: ‘S Sulawesi, 25 km E | Mamasa ( Kalama ) 1100m | 119.28.39E 3.02.10S | 1.-3.Jul 2001, Bolm lgt.’ <printed>, ‘HOLOTYPE | Phloeostiba | mamasa sp. n. | Shavrin A.V. des. 2023’ <red, printed> ( SMNS). PARATYPE: ♂ (dissected; right antennomeres 3–11 and left antennomeres 8–11 missing): ‘S Sulawesi, 8 km W | Mamasa, 950 m | 119.20.32E 2.56.13S | 18.-21.Jul1999, Bolm lgt. <printed>, ‘ PARATYPE | Phloeostiba | mamasa sp. n. | Shavrin A. V. des. 2023 <red, printed> (cSh).

Description. Measurements (n=2): HW: 0.38–0.45; HL: 0.26–0.27; OL: 0.12; TL: 0.02; AL (holotype): 0.63; PL: 0.29–0.35; PWmax: 0.47; PWmin: 0.40–0.42; ESL: 0.48–0.52; EW: 0.56–0.60; MTbL (holottype): 0.30; MTrL (holotype): 0.15 (MTrL 1–4: 0.05; MTrL 5: 0.10); AW: 0.57–0.62; AedL: 0.40; BL: 1.84–2.07 (holotype).

Habitus as in Fig. 2 . Head, pronotum, apical portions of elytra and abdomen brown to reddish-brown (middle part of head, basal portions of pronotum, paratergites and abdominal tergites III–IV in holotype slightly paler); elytra yellow-brown, with brownish latero-apical and apical portions (parascutellar portion in paratype slightly darker); antennomeres 4–11 (paratype) or 5–11 (holotype) brown; mouthparts, antennomeres 1–3 (paratype) or 1–4 (holotype) and legs yellow. Head with irregular and sparse punctation, larger and deeper in middle portion between level of anterior third of eyes, finer and sparser in middle between anteocellar foveae (paratype with indistinct fine punctation in middle); neck without or with several very fine punctures in middle; pronotum with very fine and sparse punctation, sparser in middle portion; scutellum without punctures; elytra with punctation similar to that of pronotum, but distinctly denser, finer in parascutellar and apical portions, and along suture; abdominal tergites with very fine and moderately sparse punctation, more distinct on abdominal tergite VII–VIII. Head with dense and moderately coarse microsculpture: transverse in apical portion, subdiagonal or isodiametric in middle and subdiagonal in infraorbital portions; neck with distinct transverse microreticulation; pronotum with dense and coarse microsculpture: isodiametric in medioapical and mediobasal portions, transverse in middle and subdiagonal in lateral portions; scutellum with dense transverse meshes; surface of each elytron with isodiametric microsculpture, subdiagonal in parascutellar portion and longitudinal along suture; abdomen with dense and coarse microreticulation.

Head indistinctly convex in infraorbital portions, with narrow subdiagonal anteriomedian depressions reaching level of anterior third of eyes, 1.4–1.6 times as broad as long, with narrow, moderately short and deep anteocellar foveae reaching almost level of middle length of eyes; postocular parts very short, sharply narrowed toward neck, without postocualr carina. Ocelli small, located very close to posterior narrow and moderately deep constriction, distance between ocelli about as long as distance between ocellus and posterior margin of eye. Apical palpomere narrow, about 1.3 times as long as preapical segment. Antennae almost reaching basal margin of pronotum when reclined; antennomere 5 slightly and antennomeres 6–10 distinctly transverse; basal antennomere about twice as long as broad, antennomere 2 suboval, distinctly longer than broad, 3 indistinctly narrower and longer than 2, 4 very small, about as long as broad, 5 distinctly broader than 4, 6 broader and slightly longer than 5, 7–9 slightly broader than 6, 10 slightly longer than 9, apical natennomere slightly more than twice as long as 10, from middle gradually narrowed towards subacute apex.

Pronotum relatively flattened, 1.3–1.6 times as broad as long, slightly broader than head, widest in middle, gradually narrowing toward widely rounded anterior angles and moderately sharply narrowed posteriad toward subacute posterior angles; anterior margin slightly and widely concave, about as long as rounded posterior margin; median part with very narrow longitudinal impunctate band (indistinct in mediapical half in holotype); lateral portions narrowly bordered and flattened at margins, laterobasal portions widely impressed.

Elytra slightly broader than long, 1.4–1.6 times as long as pronotum, slightly broadened apicad; posterior margins straight. Hind wings fully developed.

Metatarsi twice as long as metatibia.

Abdomen slightly broader than elytra, with two small oval wing-folding patches in middle of abdominal tergite IV, with indistinct palisade fringe at apical margin of abdominal tergite VII.

Male. Posterior margin of abdominal tergite VIII widely truncate ( Fig. 9 ). Posterior margin of abdominal sternite VIII deeply concave ( Fig. 10 ). Aedeagus suboval, with wide basal portion, mediolateral margins between basal portion and median lobe deeply concave, median lobe broad, with widely rounded apex and with moderately large rounded protrusions in latero-apical third; parameres moderately narrow and relatively short, not reaching apex of median lobe, with narrowed apical portions, with two very long and one short apical setae, and four elongate setae on inner edge of each paramere; apical part of median lobe with large dorsal lobes widely rounded apically; internal sac complicated, short and wide, with very long sclerotized structure in middle ( Fig. 7 ). Lateral aspect of the aedeagus as in Fig. 8 .

Female unknown.

Comparative notes. Phloeostiba mamasa sp. n. differs from all known species of the genus by the finer punctation of the pronotum, broader apical portion of the median lobe and different structure of the internal sac of the aedeagus.

Distribution. Phloeostiba mamasa sp. n. is known only from two localities in southern part of Sulawesi, Indonesia.

Bionomics. The specimens were collected at an elevation from 950 to 1100 m a.s.l.

Etymology. The specific epithet refers to the Mamasa community of indigenous people residing Mamasa Regency, Sulawesi.

Figures

FIGURES 1–2. Habitus of Omaliini: 1–Nipponophloeostiba explanata (holotype), 2–Phloeostiba mamasa (holotype). Scale bar: 1.00 mm.

FIGURES 7–10. Phloeostiba mamasa: 7–aedeagus (parameral view), 8–aedeagus (lateral view), 9–male tergite VIII (dorsal view), 10–male sternite VIII (ventral view). Scale bar: 0.10 mm.