Chiloneus globulus, Borovec, Roman & Perrin, Hélène, 2016

Borovec, Roman & Perrin, Hélène, 2016, On the systematic position of some species of Chiloneus, Desbrochersella and Sciaphilus, with description of two new species and lectotype selection (Coleoptera: Curculionidae: Entiminae), Zootaxa 4109 (2), pp. 131-152 : 137-139

Chiloneus globulus sp. nov.

( Figs 1–6 )

Type material. Holotype, ♀, ‘[ Algeria, Relizane, Oued Rhiou] Oued Riou 1894 / de Vauloger // 680 [p] // X [hw] / / 35 [hw] // Museum Paris / Coll. M. Pic [p] // HOLOTYPUS / Chiloneus / globulus n. sp. ♀ / Borovec & Perrin det. 2015 [p, red]’ ( MNHN, Pic coll.).

Description. Body length holotype 2.47 mm.

Body brownish, only scape and funicle yellowish, club blackish, tarsus dark brownish. Dorsal part of body densely covered by regularly rounded appressed scales ( Fig. 4 ), concealing integument, whitish grey with weak pearly sheen, on elytra irregularly scattered with small spots of light brownish scales. Elytral intervals with one regular row of inconspicuous semierect slender setae, slightly widened apicad, about as long as half of width of one interval, distance between two setae about twice as long as length of one seta. Pronotum and head with rostrum with identical semierect setae as those on elytra, sparsely irregularly scattered. Femora and tibiae with small, moderately sparse appressed rounded scales and semiappressed slender setae; scape, funicle and tarsus with short semierect setae; club finely and densely setose.

Rostrum ( Figs 1, 2 ) 1.33 times as wide as long, at basal part widest, 1.22 times as wide as rostrum at apex, at basal part distinctly tapered anteriad with straight sides, near the base constricted, shortly enlarged anteriad by ventral border of scrobe and then slightly tapered anteriad. Rostrum in lateral view almost flat, only at apical part weakly vaulted and declined anteriad. Epifrons wide, occupying majority of basal half of rostrum, just before eyes with ill-defined borders, flat, shiny, regularly and finely punctured, distance between two punctures shorter than diameter of one puncture. Frontoepistomal area shiny, moderately smooth, indistinctly finely punctured, short, subrectangular, carinate laterally, posteriorly ending in shallow, ill-defined depression. Antennal scrobe in dorsal view visible as short, posteriorly divergent furrow, open posteriad, constricted outline of rostrum; in lateral view subtriangular, distinctly enlarged posteriad, with dorsal border parallel with dorsal border of rostrum and ventral border curved downward, almost reaching ventral border of rostrum, with glabrous furrow following ventral border of scrobe. Head wide and slightly vaulted, punctured as rostrum, shiny. Eye moderately sized, distinctly vaulted and prominent from outline of head; laterally subcircular, almost reaching dorsal border of head.

Antenna slender; scape equally long as funicle, at basal two thirds very slender, at apical third weakly curved and enlarged gradually apicad, at apex 0.7 times as wide as club. Funicle segments 1 and 2 slender and conical; segment 1 1.7 times as long as wide and 1.4 times as long and 1.5 times as wide as segment 2, which is 1.8 times as long as wide; segments 3–5 isodiametric; segment 6 1.05 times as wide as long; segment 7 1.1 times as wide as long; clubs 1.6 times as long as wide.

Pronotum ( Fig. 3 ) 1.24 times as wide as long, widest at basal third with distinctly rounded sides, anteriad distinctly more tapered than posteriad, behind anterior border distinctly constricted. Disc regularly vaulted, shiny, finely, densely and regularly punctured, distance of two punctures shorter than diameter of one puncture. Base weakly arched. Pronotum in lateral view distinctly vaulted, behind anterior border flattened.

Scutellum very small, hardly visible, triangular.

Elytra ( Fig. 3 ) short-oval, 1.22 times as long as wide, widest at midlength, with regularly rounded humeri and distinctly rounded sides, broadly rounded at apex. Base weakly arched. Striae narrow, finely punctured; intervals wide, almost flat. Elytra in lateral view distinctly vaulted.

Femora edentate. Tibiae moderately short and robust, laterally straight, inside weakly enlarged; apex rounded, fringed by very fine, short, dense setae, at inner side mucronate. Tarsi short and robust, protarsi more robust than meso- and metatarsi. Protarsi with segment 2 twice as wide as long; segment 3 1.5 times as wide as long and 1.7 times as wide as segment 2; onychium 0.6 times as long as segment 3. Metatarsi with segment 2 twice as wide as long; segment 3 1.3 times as wide as long and 1.5 times as wide as segment 2; onychium 0.7 times as long as segment 3.

Male genitalia unknown.

Spermatheca ( Fig. 5 ) with long and slender, curved cornu; corpus moderately large; ramus wider than long, subtrapezoidal; nodulus long and slender, S-shaped curved. Gonocoxites not examined. Sternite VIII ( Fig. 6 ) with long and slender apodeme terminated just inside of plate; plate small, subtriangular, without basal margin, with apical margin slender, fringed by very short setae.

Etymology. This species takes its name from latin word globulus , which means small sphere, suggested by its short-oval, distinctly vaulted elytra.

Distribution. Northern Algeria (Relizane).

Differential diagnosis. This is a very unusual Chiloneus species, very easily separated and different from all others by the following set of unique characters: frontoepistomal area laterally carinate, posteriorly continuing to shallow depression, rostrum at midlength constricted by antennal scrobes, dorsal part of body covered by regularly rounded appressed scales, elytra short-oval with distinctly rounded sides, protarsi more robust than metatarsi with conspicuously transverse segment 2 and short onychium. The short-oval elytra covered by rounded appressed scales make this new species somewhat similar to some species of the tribe Holcorhinini Desbrochers des Loges, 1898. From all Holcorhinini species it is easy distinguishable by the rostrum lacking slender, mostly V-shaped transverse stria separating epifrons from the head, dorsally open, mostly pit-shaped antennal scrobes creating pterygia and V-shaped, posteriad carinate epistome.

Figures

FIGURES 1 – 6. Chiloneus globulus sp. nov.: 1 — head with rostrum, dorsal view. Scale = 0.50 mm; 2 — head with rostrum, lateral view. Scale = 0.50 mm; 3 — pronotum and elytra, dorsal view. Scale = 1.00 mm; 4 — detail of elytral vestiture. Without scale; 5 — spermatheca. Scale 0.25 mm; 6 — sternite VIII in female. Scale = 0.50 mm. Figs 7 – 17, Chiloneus tenietensis sp. nov.: 7 — head with rostrum in male, dorsal view. Scale = 0.50 mm; 8 — head with rostrum in male, lateral view. Scale = 0.50 mm; 9 — head with rostrum in female, dorsal view. Scale = 0.50 mm; 10 — head with rostrum in female, lateral view. Scale = 0.50 mm; 11 — pronotum and elytra in male, dorsal view. Scale = 1.00 mm; 12 — pronotum and elytra in female, dorsal view. Scale = 1.00 mm; 13 — detail of elytral vestiture. Without scale; 14 — penis in ventral and lateral view. Scale = 0.50 mm; 15 — spermatheca. Scale 0.25 mm; 16 — gonocoxites. Scale = 0.50 mm; 17 — sternite VIII in female. Scale = 0.50 mm. Figs 18 – 21, Chiloneus barbaricus (González): 18 — pronotum and elytra in male, dorsal view. Scale = 1.00 mm; 19 — pronotum and elytra in female, dorsal view. Scale = 1.00 mm; 20 — detail of elytral vestiture. Without scale; 21 — penis in ventral and lateral view. Scale = 0.50 mm.