Ostomopsis solitaria Scott
Creators: name: Jałoszyński, Paweł
name: Ślipiński, Adam
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Cerylonidae
Ostomopsis
Ostomopsis solitaria

description: Ostomopsis solitaria Scott
Ostomopsis solitaria Scott, 1922: 252.
(Figs 1–17, 28–31)
Type material examined. Holotype (Seychelles): sex unknown, “Silhouette / Seychelles Exp.” / “ Ostomopsis solitaria / Type H.S. Scott ” (BMNH).
Additional material examined. New Caledonia: 3 exx, Hieughène, 27.10.1978, G. Kuschel, sifted leaf litter (NZAC, MIZ). Christmas Island: 3 exx (including 2 disarticulated males), 3 km N South Point, 10.33S, 105.39E, 22.iv.1989, J.F. Lawrence, under bark & in log litter, berlesate (ANIC); 10 ex., Hughs Dale, 10.29S, 105.33E, 12- 25.iv.1989, J.F. Lawrence, leaf & log litter, berlesate (ANIC); 15 exx., vic. of Grants Well, 10.28-29S, 105.39-40E, 13-28.iv.1989, J.F. Lawrence, leaf & log litter, berlesate (ANIC). Northern Mariana Islands: 5 exx, Tinian Island, Mt. Lasso, NW slope, 18.iii.1945, H.S. Dybas, under bark and in porous wood of log (FMNH); 1 ex., Saipan Island, Papago area, 27.i.1945, H.S. Dybas, under bark and in wood (FMNH).
Emended diagnosis. Body uniformly light brown; elytra elongate, with EL/EW exceeding 1.3 and sides parallel in much more than anterior half; eyes large; sides of pronotum with conspicuously long, sparse setae; large median area on pronotum and small median area on mesoventrite virtually impunctate; punctures on sides of elytra in anterior half distinctly larger than those on median region of pronotum; prosternal process with strongly concave sides and weakly bisinuate distal margin; mesoventral process nearly twice as broad as prosternal process; scutellar shield over twice as broad as long; antennomere 3 twice as long as broad, 4–5 each strongly transverse; tegmen conspicuously short, barely longer than wide.
Redescription. Body of both sexes (Figs 28–29) elongate oval, strongly flattened; BL 0.89–1.10 mm, BL/EW 2.10–2.26; pigmentation uniformly light brown, in some specimens yellowish.
Head (Figs 28–29) subtrapezoidal, HL 0.11–0.15 mm, HW 0.25–0.33 mm; vertex and frons weakly convex; eyes large and strongly convex, coarsely faceted. Vertex and frons densely covered with shallow and tiny but distinct punctures of equal diameters and almost evenly distributed, not alveolate, those on median area separated by spaces as wide as 1–2 × their diameters; punctures on clypeus less distinct than those on frons and vertex. Setae moderately long and dense, suberect.
Antenna (Fig. 29) about as long as pronotum or indistinctly shorter, AnL 0.21–0.28 mm; scape weakly elongate, pedicel about twice as long as broad, antennomere 3 strongly elongate, twice as long as broad, 4–9 each strongly transverse, club nearly spherical and indistinctly subdivided by shallow constriction into nearly equally long, fused antennomeres 10 and 11.
Pronotum (Fig. 28) broadest near posterior third or fourth, about 1.4–1.7 × as broad as head; PL 0.20–0.25 mm, PW 0.35–0.56 mm, PL/PW 0.50–0.59; anterior margin weakly rounded, in some specimens straight at middle; anterior corners blunt and distinctly projecting anterad; lateral margins broadly rounded and sparsely crenulate; posterior corners strongly obtuse-angled but with acute tips; posterior margin shallowly bisinuate. Broad area along each lateral margin distinctly flattened and largely impunctate, with distinct submarginal line, submarginal line also developed along posterior pronotal margin, but laterally not reaching posterior corners; remaining surface of pronotum covered with very small circular, variable in diameter and slightly unevenly distributed punctures; most punctures are diffuse, only some on sides have sharp margins; several largest punctures are distributed along lateral portions of pronotal base; smaller punctures are distributed on convex portion of pronotal disc, small and sparse at middle (punctures separated by spaces 2–3 × as wide as their diameters), larger and denser on sides of convex region (where punctures are separated by spaces about 1.5 × as wide as their diameters). Dorsal setae as long as those on head, moderately dense and suberect to erect; several setae on lateral pronotal margins are about 2.5 × as long as width of flattened area along each side.
Ventral surface of prothorax (Fig. 29) with prosternal process slightly longer than wide, hourglass-shaped, with sides strongly concave, strongly broadening posterad, posterior corners rounded, distal margin indistinctly projecting posterad at middle; entire prosternum covered with circular alveolate punctures distinctly larger than those on median area of pronotum and unevenly distributed; those along anterior prosternal margin separated by spaces as wide as half diameter of punctures, those on sides of prosternum separated by spaces 0.5–1 × as wide as their diameters, median area nearly impunctate; hypomera with punctures only near prosternum, outer regions impunctate and weakly microreticulate. Setae on prosternum sparse, short and nearly recumbent; setae on hypomera barely discernible; anterior prosternal margin microcrenulate and with dense row of short setae directed anterad.
Mesoventrite (Fig. 29) with mesoventral process between mesocoxae with sides projecting laterad to form pair of round lateral convexities, about twice as wide as prosternal process; surface covered with variously large circular alveolate punctures slightly larger than those on prosternum, on anteromedian area sparse, separated by spaces 1–3 × as wide as their diameters, on sides denser, area between mesocoxae almost impunctate.
Metaventrite (Fig. 29) strongly transverse, clearly longer than mesoventrite; large median area impunctate, with variously visible, in most specimens distinct discrimen in posterior 1/3–1/2; circular alveolate punctures distributed mainly along posterior margins of mesocoxae and anterior margins of metacoxae, where distances between punctures are slightly narrower than their diameters; largest punctures comparable to those on mesoventrite. Posterior metaventral margin between metacoxae slightly concave.
Hind wings long and functional.
Elytra (Fig. 28) together semioval, 2.7–3.2 × as long as pronotum and indistinctly broader than pronotum; EL 0.58–0.80 mm, EW 0.40–0.60 mm, EL/EW 1.33–1.47. Sides nearly parallel in anterior 2/3, evenly rounded in posterior 1/3; narrow area along each lateral margin distinctly flattened; humeri slightly obtuse-angled, humeral calli weakly marked; each elytron with nine longitudinal rows of small, circular punctures, but those in median half of each elytron are in most specimens indistinct; all punctures with diffuse margins, slightly smaller than largest pronotal punctures, except for unevenly distributed pits along lateral margins; remaining cuticle virtually impunctate; setae similar to those on pronotum. Epipleura (Fig. 29) near middle length slightly narrower than metafemur, weakly narrowing, or even indistinctly broadening from near middle, each with indistinct undulate ridge along mesal margin.
Mesoscutellar shield (Fig. 28) subtrapezoidal, distinctly over twice as broad as long, with sides straight in front of broadest site, lateral corners rounded, posterior margin angulate with indistinctly sinuate lateral portions.
Abdominal ventrites (Fig. 29) together indistinctly longer than meso- and metaventrite combined; ventrite 1 subequal in length to 2–4 together, with only a few very shallow circular and sparse punctures on sides; ventrite 2 with transverse ridge bearing several triangular posterior projections and situated just behind anterior margin, ventrites 2–5 with fine, inconspicuous punctures.
Aedeagus (Figs 30–31); tegmen conspicuously short, with rounded apex and lateral apical groups of 4–5 short setae; penis nearly filiform, with subtriangular and rounded apex.
Distribution. Seychelles, New Caledonia, Christmas Island, Northern Mariana Islands.
Remarks. The identity of this species is somewhat uncertain; the holotype was not dissected due to its fragile condition, and no additional material from the Seychelles was available for dissections. For this reason, identifications of specimens from other regions are based on external characters, which seem stable, but may require verification when additional material collected in the type locality for O. solitaria becomes available.
Ostomopsis solitaria is most similar to O. neotropicalis and O. solomon; see Remarks for O. neotropicalis.
description: Published as part of Jałoszyński, Paweł & Ślipiński, Adam, 2021, Revision of the subfamily Ostomopsinae (Coleoptera: Cerylonidae), pp. 459-481 in Zootaxa 4985 (4) on pages 474-476, DOI: 10.11646/zootaxa.4985.4.2, http://zenodo.org/record/4964117