Omotrachelus kaniai Borovec, 2023

Borovec, Roman, 2023, New data on Omotrachelus Kolbe, with description of five new species (Coleoptera; Curculionidae; Entiminae; Cneorhinini), Zootaxa 5357 (4), pp. 502-514 : 506-508

Omotrachelus kaniai Borovec sp. nov.

Figs (2, 7, 12, 18)

http://zoobank.org/ urn:lsid:zoobank.org:act:152CF1E0-56E5-4CE6-92F6-ED2AA5517078

Type locality. Sierra Leone, Tiwai Island , Moa River .

Type material. Holotype: ♁, Sierra Leone, Tiwai Island , Moa River, N 07°33′00″, W 11°21′09″, 120 m, 17–22.vi.16, General Coll. Leg. Takano, Miles & Goff, ANHRT 18: SL-001 ( BMNH) . Paratypes: 2 ♁, 1 ♀, same data as holotype ( BMNH) .

Description. Body length holotype 3.88 mm, paratypes 3.75–3.88 mm. Body densely covered with regularly rounded appressed scales, well isolated, finely striate, 4–5 across width of one interstria, scales on pronotum and head with rostrum same, but smaller. All elytral interstriae with one dense row of erect setae, at posterior declivity about as long as half width of one interstria, on disc shorter; setae slender, parallel-sided, apically rounded, distance between two setae slightly longer than length of one seta. Erect setae on pronotum and head with rostrum similar, irregularly scattered, on anterior margin of pronotum and head with rostrum slightly shorter than elytral setae, on disc of pronotum very short, conspicuously shorter than those on elytra. Inner side of scapes and femora with tibiae with short, semi-erect, slender setae, inconspicuously prominent from outline. Vestiture greyish brown, with small whitish spot at middle of interstria 5.

Rostrum ( Fig. 7 ) short, at base 1.07–1.13× as wide as long, at base 1.13–1.16× as wide as at apex, evenly tapered apicad, at basal part slightly more tapered than in apical portion; in lateral view regularly vaulted. Epifrons at base slightly slenderer than base of rostrum, conspicuously evenly tapered anteriad with straight sides, at base 1.55– 1.67× as wide as between antennal insertions, dorsally shallowly longitudinally depressed. Frons short, glabrous, smooth, transversely deeply depressed. Epistome short, U-shaped. Antennal scrobes in dorsal view visible along entire length as narrow furrow, slightly narrower at midlength; in lateral view narrow, slightly curved, directed to ventral margin of eye and teaching it. Vertex slightly wider than space between antennal insertions, flat, with short, slender, median longitudinal stria. Eyes mid-sized, in dorsal view slightly prominent from outline of head; in lateral view subcircular, dorsally placed, almost touching dorsal margin of head.

Antennae ( Fig. 2 ) slender; scape 5.5–5.8× as long as wide, slightly curved at apical third and here evenly, weakly enlarged apicad, at apex 0.8× as wide as club. Funicle segment 1 long and slender, 2.5–2.7× as long as wide and 1.3–1.4× as long as segment 2, this is 2.2–2.4× as long as wide; segments 3 and 4 isodiametric; segments 5 and 6 1.1–1.2× as wide as long; segment 7 1.2–1.3× as wide as long; club 1.7–1.8× as long as wide.

Pronotum ( Fig. 2 ) short and very wide, 1.85–1.92× as wide as long, widest at base, here in very short part rounded, distinctly tapering anteriad, behind anterior margin slightly constricted; base slightly prominent posteriad at middle; disc regularly domed, moderately roughly punctured, with 4–5 punctures across length of pronotum, distance between punctures about equal to their diameter; pronotum in lateral view flat.

Elytra ( Fig. 2 ) subglobular, 1.03–1.07× as long as wide, widest at midlength, with distinctly and regularly rounded sides, apically broadly rounded, behind base only indistinctly constricted, interstria 9 behind quarter from base with a hump, bigger in males than in female, in males well, in female hardly visible in dorsal view. Base slightly arched. Beneath scales striae densely and deeply punctured, about as wide as smooth, shiny interstriae. All interstriae equally wide and slightly vaulted.

Protibiae slender, 6.4–6.7× as long as at midlength wide, apically rounded, fringed by yellow setae, at short apical portion curved inside and finely denticulate. Tarsi slender; segment 2 isodiametric; segment 3 1.5–1.6× as wide as long and 1.8–1.9× as wide as segment 2; onychium 1.2–1.3× as long as segment 3.

Penis ( Fig. 12 ) moderately long, 2.4–2.5× as long as wide, in dorsal view in basal two thirds subparallel-sided, in apical third tapering apicad with rounded sides, tip distinctly separated, constricted, apically obtuse; in lateral view curved, widest behind middle, evenly tapering apicad, tip distinctly curved; temones slightly more than twice as long as body of penis. Endophallus with two equally long sclerites.

Spermatheca ( Fig. 18 ) with regularly curved, equally wide cornu; corpus rounded; ramus distinctly wider than long, rounded; collum subtriangular, distinctly narrower than ramus. Sternite VIII with apodeme touching anterior margin of plate; plate umbrella-shaped, regularly rounded, about as long as wide. Gonocoxites narrowly subtriangular with long apical styli.

Biology. Unknown.

Etymology. This species is dedicated to Jaroslav Kania (Wrocław, Poland), a specialist in Cneorhinini ( Entiminae ) and author of the last paper regarding the genus Omotrachelus .

Remarks. Omotrachelus kaniai is similar only to O. angulatus Hustache, 1932 , known from Ivory Coast by the regularly rounded, ball-shaped elytra with an indistinct, short basal constriction. It is also distinguishable from it by the following set of characters: smaller, 3.7–3.8 mm, antennal scrobes in lateral view directed to ventral margin of eye, pronotum longer, 1.85–1.92× as wide as long, in lateral view flat, protibiae slender, 6.4–6.7× as long as at midlength wide, penis long ( Fig. 12 ), 2.4–2.5× as long as wide, tip in dorsal view distinctly enlarged apicad, in lateral view curved, and ramus of spermatheca distinctly wider than long ( Fig. 18 ). In O. angulatus , adults are larger, 4.5–4.9 mm, the antennal scrobes in lateral view are directed to the middle of eye, pronotum shorter, 2.83–2.94× as wide as long, in lateral view distinctly swollen behind anterior margin, protibiae more robust, 5.4–5.8× as long as at midlength wide, penis short ( Fig. 13 ), 1.8× as long as wide, tip in dorsal view regularly tapered apicad, in lateral view straight and ramus of spermatheca as long as wide ( Fig. 19 ).

Figures

FIGURES 6–10. Head with rostrum in dorsal and lateral view. 6. Omotrachelus geiseri. 7. O. kaniai. 8. O. longirostris. 9. O. parallelus. 10. O. thoracomimus. Scale 0.50 mm.

FIGURES 1–4. Dorsal habitus. 1. Omotrachelus geiseri. 2. O. kaniai. 3. O. longirostris. 4. O. parallelus. Not to scale.

FIGURES 11–21. 11–16: penis in dorsal and lateral view. 11. Omotrachelus geiseri. 12. O. kaniai. 13. O. angulatus. 14. O. longirostris. 15. O. parallelus. 16. O. thoracomimus. 17–21: spermatheca. 17. O. geiseri. 18. O. kaniai. 19. O. angulatus. 20. O. longirostris. 21. O. parallelus. Scale 0.125 mm for 20, 21; 0.25 mm for 17–19; 0.50 mm for 11, 12, 14–16; 1.00 mm for 13.