Ostomopsis kuscheli, Jałoszyński & Ślipiński, 2021

Jałoszyński, Paweł & Ślipiński, Adam, 2021, Revision of the subfamily Ostomopsinae (Coleoptera: Cerylonidae), Zootaxa 4985 (4), pp. 459-481 : 468-471

Ostomopsis kuscheli sp. n.

( Figs 21–24 )

Type material examined. Holotype ( New Caledonia ): sex unknown, “ NEW CALEDONIA / Col d’Amieu, 550m / 15 Oct 1978 / G. Kuschel ” [white, printed], “Sifted litter / and rotten wood / 78/229” [white, printed] ( NZAC) . Paratypes (24 exx): New Caledonia : 2 exx, Col d’Amieu, 500 m, 15.X.1978, G. Kuschel, sifted litter and rotten wood, 78/229 ( MIZ, NZAC) ; 2 exx, Kavatch , near Hienghene, 450 m, 28.X.1978, G. Kuschel, sifted litter and rotten wood, 78/261 ( NZAC) ; 1 ex., Mt Rembai , 800 m, nr. Col. d’ Amieu, 17.X.1978, G. Kuschel / sifted litter and rotten wood, 78/237 ( NZAC) ; 5 exx, Mt. Koghis near Noumea, 500 m, 13.viii.1978, S.&J. Peck ( ANIC; CNC) ; 2 exx, same locality and collectors but Auberge , 13 and 26.viii.1978 ( CNC) ; 4 exx., same collector but Col d’Amieu , 500 m, N of La Foa, 7.viii.1978 ( ANIC) ; 4 exx, Pic d’Amoa, N slopes, 20.58S 165.17E, 31.i.2002, G. Monteith, pyrethrum, tress, logs ( QMB) ; 1 ex., Mandjelia summit, 20°24’S, 164°32’E, 750 m, 6-7.ii.2001, C. Burwell, G. Monteith, pyrethrum, trees & logs ( QMB) ; 2 exx, Aoupinié , Goipin road junction to gate, -21.1814, 165.2879, 700- 900 m, sifted, R. Ruta, M. Wanat ( MNHW) ; 2 exx, same data except for -21.1746, 165.3097, 700 m, near Hibbertia, above gravel pit, sifting leaf litter ( MNHW) ; 1 ex., Pic d’Amoa (Povila), -20.9502, 165.2932, 450 m, rainforest, sifting leaf litter, M. Wanat, R. Ruta ( MNHW) .

Diagnosis. Body in fully pigmented specimens with nearly black head and pronotum and brown elytra; elytra stout, with EL/EW not exceeding 1.1 and sides parallel only in anterior third or less; eyes large; sides of pronotum with conspicuously long, sparse setae; median area on pronotum and median area on mesoventrite punctate; punctures on sides of elytra in anterior half distinctly larger than those on median region of pronotum; prosternal process with weakly concave sides and strongly rounded distal margin; mesoventral process only slightly broader than prosternal process; scutellar shield twice as broad as long; antennomere 3 three times as long as broad and antennomeres 4–5 each slightly elongate; tegmen strongly elongate, about as long as penis.

Description. Body of both sexes ( Figs 21–22 ) short oval, moderately convex; BL 1.35–1.73 mm, BL/EW 1.58–1.74; pigmentation variable, in most specimens distinctly bicolored: head and pronotal disc dark brown, nearly black, lateral pronotal margins, elytra, ventral side and appendages much lighter, brown with umbra or reddish hue; contrast between darker and lighter areas in some specimens indistinct, and in a few beetles body uniformly dark brown with umbra hue.

Head ( Figs 21–22 ) subtrapezoidal, HL 0.15–0.23 mm, HW 0.36–0.45 mm; vertex and frons weakly convex; eyes large and strongly convex, coarsely faceted. Vertex and frons densely covered with shallow but distinct punctures of unequal diameters and slightly unevenly distributed, those on sides tend to be more distinct, nearly alveolate, those on median area are smaller and with diffuse margins; distances between punctures on median area equal to 1–3 diameters of punctures, on sides punctures are slightly denser; punctures on clypeus indistinct, especially anteriorly. Setae long and dense, erect.

Antenna ( Fig. 22 ) about as long as pronotum, AnL 0.33–0.45 mm; scape weakly elongate, pedicel 2.5 × as long as broad, antennomere 3 strongly elongate, 3 × as long as broad, 4–5 each indistinctly elongate, 6 and 7 each about as long as broad, 8 indistinctly transverse, 9 nearly twice as broad as long, club elongate and distinctly subdivided by constriction into equally long, fused antennomeres 10 and 11.

Pronotum ( Fig. 22 ) broadest near posterior third or fourth, nearly twice as broad as head; PL 0.35–0.45 mm, PW 0.70–0.88 mm, PL/PW 0.46–0.53; anterior margin evenly, weakly rounded; anterior corners blunt and distinctly projecting anterad; lateral margins broadly rounded and with sparsely distributed crenules; posterior corners blunt, slightly obtuse-angled; posterior margin distinctly bisinuate. Relatively broad area along each lateral margin distinctly flattened and largely impunctate, with distinct submarginal line; remaining surface of pronotum covered with circular, variable in diameter and depth, unevenly distributed punctures; largest are distributed along flattened margins and along lateral portions of pronotal base, on these areas spaces between punctures are clearly narrower than their diameters; medium-size punctures are distributed near anterior pronotal margin and separated by spaces subequal to their diameters; large median region of pronotal disc with smallest punctures, partly alveolate, partly with diffuse margins, unevenly distributed, with spaces between them ranging from 1 to 3 diameters of punctures. Setae distinctly longer than those on head, dense and erect; those on lateral pronotal margins over twice as long as width of flattened area along each side.

Ventral surface of prothorax ( Fig. 22 ) with prosternal process about as long as wide, with sides indistinctly concave, slightly broadening posterad, posterior corners blunt, obtuse-angled and slightly projecting laterad, distal margin strongly convex; entire prosternum covered with circular and oval alveolate punctures distinctly larger than those on median area of pronotum and unevenly distributed; those along anterior prosternal margin nearly touching one another, those behind them separated by spaces 1/2–2 × as wide as diameters of punctures; hypomera punctate only in inner halves, with punctures smaller, less sharply defined but similarly dense as those on prosternum; outer regions of hypomera impunctate and smooth. Setae on prosternum sparse, short and nearly recumbent, present mostly on anterior half; setae on hypomera much shorter, barely discernible; anterior prosternal margin microcrenulate and with dense row of short setae directed anterad.

Mesoventrite ( Fig. 22 ) with mesoventral process between mesocoxae with concave sides, expanding distad and only slightly broader than prosternal process; mesoventrite with pair of large and shallow oval impressions in front of mesocoxae, remaining surface covered with variously large circular punctures, some alveolate, some with diffuse margins, in median area as large as the largest punctures on prosternum and unevenly distributed, some nearly touching one another, between mesocoxae punctures are indistinctly smaller and separated by spaces subequal to their diameters.

Metaventrite ( Fig. 22 ) strongly transverse, medially subequal in length to mesoventrite; large median area impunctate, with variously visible, in most specimens indistinct, short discrimen in posterior 1/3 or 1/4; sides with variously large circular punctures, some with sharply marked, and some with diffuse margins, spaces between punctures subequal to their diameters or slightly wider. Posterior metaventral margin between metacoxae nearly straight.

Hind wings long and functional.

Elytra ( Fig. 21 ) together drop-shaped, 2.2–2.6 × as long as pronotum and indistinctly broader than pronotum; EL 0.83–1.05 mm, EW 0.80–1.05 mm, EL/EW 1.00–1.09. Sides parallel in anterior 1/5–1/4 or barely noticeably broadening just behind humeri, evenly rounded and strongly convergent posterad in posterior 2/3; 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, at least some of those on anteromedian third with sharply defined margins, slightly smaller than largest pronotal punctures, punctures reducing in diameter toward apices; remaining cuticle virtually impunctate; setae similar to those on pronotum. Epipleura ( Fig. 22 ) near middle length slightly broader than width of metafemur, gradually and weakly narrowing posterad, each with undulate ridge along mesal margin.

Mesoscutellar shield ( Fig. 21 ) subtrapezoidal, distinctly over twice as broad as long, with sides nearly straight in front of broadest site, lateral corners rounded, posterior margin weakly arcuate.

Abdominal ventrites ( Fig. 22 ) together slightly longer than meso- and metaventrite combined; ventrite 1 nearly as long as 2–4 together, with lateral groups of circular alveolate punctures similar in diameters to those on sides of metaventrite and separated by spaces subequal to or narrower than their diameters, median and posterior regions impunctate; ventrite 2 with transverse row of small diffuse punctures, ventrites 3–5 with indistinct, inconspicuous punctures.

Aedeagus ( Figs 23–24 ); tegmen ( Fig. 23 ) over twice as broad as penis and strongly elongate, with rounded sides broadly constricted in median and subapical regions, with three pairs of thick lateral subapical setae and rounded apex; penis ( Fig. 24 ) slender, broadly constricted in sub-basal region, with rounded apex.

Etymology. This species is dedicated to the late Guillermo Kuschel, who collected some specimens used in our study, including the holotype of this species.

Distribution. New Caledonia.

Remarks. Ostomopsis kuscheli is a highly variable species; the largest specimens are 30% longer than the smallest ones; the proportions of body parts and the pigmentation also vary. Besides the aedeagus, all specimens share the generally stout body form with the elytra drop-shaped, conspicuously long and erect setae, and a remarkable pattern of punctures. Fully pigmented specimens can be easily distinguished from all remaining Ostomopsis species by their bicolored pigmentation. Only adults of O. kuscheli and O. watti have suboval bodies with the elytra narrowing toward apices from less than anterior half; all remaining species are more elongate, with elytra more parallel-sided anteriorly. Externally, O. kuscheli differs from O. watti in having much more distinct elytral rows of punctures, especially on sides (in O. watti the rows are indistinct on entire elytra); the antennomere 3 about three times as long as wide (in O. watti about twice as long), antennomeres 4 and 5 each slightly elongate (in O. watti each transverse); the presence of a pair of shallow circular impressions on the anteromedian region of the metaventrite; and in the strongly elongate tegmen (conspicuously short in O. watti ).

Figures

FIGURES 21–24. Ostomopsis kuscheli sp. n. Dorsal (21) and ventral (22) habitus, aedeagus (23) and penis in dorsal view (24).