Ostomopsis Scott, 1922

Jałoszyński, Paweł & Ślipiński, Adam, 2021, Revision of the subfamily Ostomopsinae (Coleoptera: Cerylonidae), Zootaxa 4985 (4), pp. 459-481 : 461-466

publication ID	https://doi.org/ 10.11646/zootaxa.4985.4.2
publication LSID	lsid:zoobank.org:pub:B6A54BD5-BDCD-4763-A600-A8BEA18D868B
DOI	https://doi.org/10.5281/zenodo.4964121
persistent identifier	https://treatment.plazi.org/id/03F287B2-EE68-7448-FF08-F926CEFCFC12
treatment provided by	Plazi
scientific name	Ostomopsis Scott
status

Treatment

Genus Ostomopsis Scott View in CoL View at ENA

Ostomopsis Scott, 1922: 250 View in CoL . Type species: Ostomopsis solitaria Scott, 1922 (orig. des.).

Diagnosis. Body of adults around 1–2 mm long, strongly flattened to moderately convex, densely setose; sides of pronotum and elytra flattened; head lacking occipital ridge; frontoclypeal groove (‘suture’) present; antenna decamerous with large, nearly spherical or oval club composed of fused antennomeres 10 and 11, with variously distinct constriction marking fusion site; terminal maxillary and labial palpomeres slightly asymmetrical, each tapering to rounded apex; head ventrally with long subocular ridges; lateral pronotal edges crenulate; prosternum laterally largely fused with hypomera, vestiges of notosternal sutures developed only at anteroventral prothoracic margin; prosternal process subrectangular, subtrapezoidal or hourglass-shaped; procoxal cavities externally and internally open; mesocoxae broadly separated; metaventrite and abdominal ventrite 1 lacking postcoxal lines; tarsi 3-3-3 with tarsomeres not projecting distoventrad; empodium present; elytra with nine rows of punctures; terminal ventrite crenulate; aedeagus with penis slender with paired struts, tegmen with fused parameres.

Description. Body ( Figs 19–20 View FIGURES 19–20 , 21–22 View FIGURES 21–24 , 25–26 View FIGURES 25–27 , 28–29 View FIGURES 28–31 , 32–33 View FIGURES 32–33 , 34–35 View FIGURES 34–37 ) oval, flattened to moderately convex, with shallow constriction between pronotum and elytra.

Head ( Figs 1–4 View FIGURES 1–4 ) sub-prognathous, large in relation to pronotum, slightly flattened, subtrapezoidal. Occipital region not demarcated; vertex and frons ( Fig. 1 View FIGURES 1–4 ; vt, fr) confluent; tempora long and weakly convergent posterad; frontoclypeal groove ( Fig. 1 View FIGURES 1–4 ; fcg) present, arcuate; clypeus large, semioval, transverse, weakly declining. Antennal fossae ( Fig. 2 View FIGURES 1–4 ; anf) broadly separated, hidden under anterolateral margin of frons; eyes (if present) situated anteriorly and slightly above middle height of head.

Gular region not demarcated, gular sutures lacking; submentum ( Fig. 3 View FIGURES 1–4 ; smn) transverse with straight anterior margin; sides of ventral surface of head with longitudinal subocular ridge ( Fig. 3 View FIGURES 1–4 ; sor).

Antennae ( Fig. 3 View FIGURES 1–4 ) decamerous, with strongly enlarged subcylindrical or fusiform scape ( Fig. 3 View FIGURES 1–4 ; sc); pedicel ( Fig. 3 View FIGURES 1–4 ; pd) much narrower than scape, in all species elongate; antennomeres 3–6 subequal in width, 7–9 gradually broadening and each transverse; terminal segment apparently representing the fusion of two antennomeres, forming a spherical or oval club with variously distinct fusion site marked as constriction and bearing digitiform sensilla.

Labrum ( Figs 2–3 View FIGURES 1–4 ; lbr; 5) transverse with rounded anterior margin, several pairs of long and several pairs of short dorsal and anterior setae. Mandibles ( Figs 2, 4 View FIGURES 1–4 ; md; 6–7) subtriangular and robust, symmetrical, each with broad base bearing large tuberculate mola ( Figs 6–7 View FIGURES 5–10 ; mo), long setose prostheca ( Fig. 6 View FIGURES 5–10 ; pst) and slender, curved apical region with three small and blunt apical teeth (only two can be seen in Figs 6–7 View FIGURES 5–10 ); lateral mandibular margin convex in distal third, bulging near middle, where several long setae are inserted, and concave in basal third. Maxilla with short and broad cardo ( Fig. 3 View FIGURES 1–4 ; cd), subtriangular and elongate basistipes ( Figs 3 View FIGURES 1–4 , 8–9 View FIGURES 5–10 ; bst), moderately broad and short mediostipes ( Figs 3 View FIGURES 1–4 , 8 View FIGURES 5–10 ; mst), elongate palpifer ( Figs 3 View FIGURES 1–4 , 8 View FIGURES 5–10 ; ppf); galea and lacinia ( Figs 8–9 View FIGURES 5–10 ; gal, lac) short and slender, each with dense setae along mesal and distal margins; maxillary palp larger than galea and lacinia, with palpomere 1 ( Figs 3 View FIGURES 1–4 , 8 View FIGURES 5–10 ; mxp1) minute, subcylindrical and elongate, palpomere 2 ( Figs 3 View FIGURES 1–4 , 8 View FIGURES 5–10 ; mxp2) large, asymmetrical, subtriangular in ventral view with base situated mesally, palpomere 3 ( Figs 3 View FIGURES 1–4 , 8 View FIGURES 5–10 ; mxp3) slightly narrower and much shorter than 2, subcylindrical and annulate, palpomere 4 ( Figs 3 View FIGURES 1–4 , 8 View FIGURES 5–10 ; mxp4) distinctly narrower and much longer than 3, approximately conical, nearly symmetrical and with broadly rounded or truncate apex. Mentum ( Figs 3 View FIGURES 1–4 , 10 View FIGURES 5–10 ; mn) subtrapezoidal, broadest at base, with angulate sub-basal transverse carina and longitudinal median carina dividing its ventral surface into three regions; prementum ( Figs 3 View FIGURES 1–4 , 10 View FIGURES 5–10 ; pmn) narrower than distal mental margin, about as long as broad or slightly transverse, partly membranous and densely setose; labial palps large, with palpomere 1 ( Figs 3 View FIGURES 1–4 , 10 View FIGURES 5–10 ; lp1) minute, subcylindrical and elongate; palpomere 2 ( Figs 3 View FIGURES 1–4 , 10 View FIGURES 5–10 ; lp2) large, asymmetrical, in ventral view subtriangular or semioval with base situated mesally; palpomere 3 ( Figs 3 View FIGURES 1–4 , 10 View FIGURES 5–10 ; lp3) narrower and shorter than 2, asymmetrical, usually with sinuate margins, tapering toward weakly rounded apex.

Tentorium ( Figs 1–2 View FIGURES 1–4 ) with bisinuate tentorial bridge ( Figs 1–2 View FIGURES 1–4 ; tb) bearing long anteromedian projection, posterior tentorial arms ( Figs 1–2 View FIGURES 1–4 ; pta) short, connection with ventral wall of head not marked externally (i.e., posterior tentorial pits lacking); dorsal tentorial arms ( Figs 1–2 View FIGURES 1–4 ; dta) short, situated between eyes and fused with dorsal wall of head; anterior arms ( Figs 1–2 View FIGURES 1–4 ; ata) slender, extending to antennal fossae.

Prothorax ( Figs 11–12 View FIGURES 11–17 , 19 View FIGURES 19–20 , 21 View FIGURES 21–24 , 25 View FIGURES 25–27 , 28 View FIGURES 28–31 , 32 View FIGURES 32–33 , 34 View FIGURES 34–37 ) transverse and broadest behind middle. Pronotum with anterior margin arcuate; anterior corners distinct, subtriangular, projecting anterad; lateral margins sharply marked, crenulate, rounded; posterior corners well-marked; posterior margin arcuate or bisinuate. Variously broad area along each lateral margin strongly flattened and nearly impunctate, remaining surface of pronotum with dense punctures.

Prosternum ( Figs 11–12 View FIGURES 11–17 ; pst) only slightly shorter than pronotum, laterally largely fused with hypomera, with only vestiges of notosternal sutures ( Fig. 11 View FIGURES 11–17 ; nss) marked at anterior margin; prosternal process ( Fig. 11 View FIGURES 11–17 ; psp) flat, subrectangular, subtrapezoidal or hourglass-shaped, its sides concealing mesal portions of procoxae. Surface of prosternum, including procoxal process, densely punctate. Hypomera ( Fig. 11 View FIGURES 11–17 ; hy) elongate, concave, at least their outer regions impunctate.

Mesonotum ( Fig. 13 View FIGURES 11–17 ) with transverse mesoscutum ( Fig. 13 View FIGURES 11–17 ; sc2) and transverse mesoscutellum ( Fig. 13 View FIGURES 11–17 ; scl2) well-visible in intact specimens; scutoscutellar suture ( Fig. 13 View FIGURES 11–17 ; sss) distinct.

Metanotum in winged species ( Fig. 14 View FIGURES 11–17 ) with large metascutum ( Fig. 14 View FIGURES 11–17 ; sc3) and prominent alacristae ( Fig. 14 View FIGURES 11–17 ; alc) separated by median groove ( Fig. 14 View FIGURES 11–17 ; mg); metapostnotum ( Fig. 14 View FIGURES 11–17 ; pn3) strongly transverse, short.

Mesoventrite ( Fig. 16 View FIGURES 11–17 ; v 2 View FIGURES 1–4 ) transverse, with short and slightly impressed procoxal rests near anterior margin (visible in Fig. 20 View FIGURES 19–20 ), median region weakly convex or flat, in all species densely punctate; mesoventral process ( Fig. 16 View FIGURES 11–17 ; mvpi) at least slightly, and in most species much broader than prosternal process, its posterior margin indistinct.

Metaventrite ( Fig. 16 View FIGURES 11–17 ; v 3 View FIGURES 1–4 ) in winged species longer than mesoventrite, broader than long and slightly broadening posterad, with variously distinct discrimen ( Fig. 16 View FIGURES 11–17 ; dsc) in posterior region. Postcoxal lines lacking. Metacoxae broadly separated, posteromesal margin of metaventrite concave or straight.

Metendosternite ( Fig. 16 View FIGURES 11–17 ) with broad, lamellate stem and strongly divergent furcal arms ( Fig. 16 View FIGURES 11–17 ; mtfa), each with submedian anterior arm and additional distal arm just below distal muscle attachment disc.

Wings in most species well-developed and functional; one species wingless.

Elytra ( Fig. 15 View FIGURES 11–17 ) elongate, each with distinct lateral flattening, sharp lateral carina and eight or nine rows of punctures, but some may be indistinct or slightly irregular; epipleura (e.g., Fig. 20 View FIGURES 19–20 ) sub-horizontal, flat, each with undulate ridge along mesal margin.

Legs ( Figs 11, 16 View FIGURES 11–17 ) short and robust. Procoxa subglobose, mesocoxa much larger and oval, metacoxa strongly transverse. All trochanters subtriangular and elongate with oblique distal margin. All femora distinctly flattened laterally, with dorsal and ventral margins convex. All tibiae slender, lacking apical or subapical teeth. All tarsi trimerous, with subcylindrical tarsomeres, lacking distoventral lobes. Claws long; empodium present.

Abdomen ( Fig. 17 View FIGURES 11–17 ) longer than meso- and metaventrite together, subtriangular and rounded at sides; five ventrites visible, with ventrite 1 ( Fig. 17 View FIGURES 11–17 ; av1) the longest. Posterior margin of terminal ventrite and tergite finely crenulate, the latter interlocking with apical microtrichial field of ventral side of elytra.

Aedeagus ( Figs 23–24 View FIGURES 21–24 , 27 View FIGURES 25–27 , 31 View FIGURES 28–31 , 36–37 View FIGURES 34–37 ) with strongly elongate, slender penis with two long articulated anterior struts; tegmen various in shape, from strongly elongate to conspicuously short, lacking articulated parameres, with lateral apical groups of setae and dorsal articulated strut.

Ovipositor ( Fig. 18 View FIGURE 18 ) with broad, elongate gonocoxites ( Fig. 18 View FIGURE 18 ; gcx) and slender, subcylindrical gonostyli ( Fig. 18 View FIGURE 18 ; gst) bearing apical setae.

Sexual dimorphism not observed.

Natural history. Ostomopsis species are associated with rotten palm wood, subcortical environments or leaf litter; immature stages unknown. Hindguts of dissected specimens are often tightly packed with fungal spores ( Fig. 18 View FIGURE 18 ), so adults are sporophagous on fungi.

Composition and distribution. Six species are known so far, inhabiting Seychelles Islands, Thailand, Malaysia, Christmas Island, Northern Mariana Islands, New Caledonia and Loyalty Islands, New Guinea and Solomon Islands, USA (Florida), Cuba, Hispaniola, Jamaica, Guadeloupe, Montserrat, Mexico (San Luis Potosi, Veracruz), Costa Rica, and Panama.

Remarks. Judging from collecting records, which seem still to be rather fragmentary, the genus will probably turn out to be circumtropical. In addition to four new species described below, single specimens of at least five additional undescribed species were seen from New Guinea, the Solomons, Costa Rica, Panama and Malaysia (Sabah, Pahang).

Identification key to the species of Ostomopsis

1 Body short oval, with short and not-parallel-sided elytra, EL/EW <1.1 ( Fig. 21 View FIGURES 21–24 )................................... 2

- Body elongate, with elytra in anterior half parallel-sided, EL/EW at least 1.3 ( Fig. 19 View FIGURES 19–20 )............................... 3

2 Fully pigmented specimens bicolored, with nearly black head and pronotum and brown elytra; punctures on sides of elytra in anterior half distinctly larger than those on median region of pronotum; 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 ( Figs 21, 22 View FIGURES 21–24 )............................................................. O. kuscheli Jałoszyński & Ślipiński

- Fully pigmented specimens uniformly light brown; punctures on sides of elytra in anterior half about as small or indistinctly larger than those on median region of pronotum; scutellar shield distinctly more than twice as broad as long; antennomere 3 about twice as long as broad and antennomeres 4–5 each transverse; tegmen conspicuously short, several times shorter than penis ( Figs 36, 37 View FIGURES 34–37 )........................................................... O. watti Jałoszyński & Ślipiński

3 Eyes lacking ( Fig. 19 View FIGURES 19–20 ); punctures on head large, sharply marked and dense, denser than those on median region of pronotum; prosternal process nearly parallel-sided with rounded distal margin............ Ostomopsis cudak Jałoszyński & Ślipiński

- Eyes large and strongly convex; punctures on head small, with diffuse margins and sparse, similarly dense as those on median region of pronotum; prosternal process with strongly concave sides and distal margin straight or bisinuate............... 4

4 Large median area on pronotum ( Fig. 28 View FIGURES 28–31 ) and small median area on mesoventrite impunctate. ............ O. solitaria Scott

- Median area on pronotum and entire mesoventrite punctate. .................................................... 5

5 Finely and sparsely punctate: interstices between rows of punctures on anterior half of each elytron distinctly wider than punctures ( Fig. 25 View FIGURES 25–27 ); most pronotal punctures separated by spaces wider than their diameters; punctures on median area of prosternum separated by spaces wider than their diameters; antennomere 3 clearly more than twice as long as broad, and antennomere 4 about as long as broad. ...................................... .. O. neotropicalis Lawrence & Stephan

- With large and dense punctures: interstices between rows of punctures on anterior half of each elytron as wide as punctures ( Fig. 32 View FIGURES 32–33 ); most pronotal punctures separated by spaces equal to or narrower than their diameters; punctures on median area of prosternum separated by spaces subequal to their diameters; antennomere 3 clearly less than twice as long as broad, and antennomere 4 strongly transverse............................................ O. solomon Jałoszyński & Ślipiński