Oxycheila buestani Wiesner, 1999

Šafránek, Ondřej, Serrano, Verónica Lucía Caballero & Carrasco, Juan Carlos, 2023, Rediscovery and redescription of Oxycheila buestani Wiesner with the first female record and new methodology for observation of Oxycheila Dejean and Oxygonia Mannerheim (Coleoptera: Cicindelidae), Zootaxa 5353 (2), pp. 131-142 : 136-138

Oxycheila buestani Wiesner, 1999

( Figs 15‒26 )

Oxycheila buestani Wiesner, 1999: 39 .

Type locality. Ecuador, Guayas, 2, 5 km north of Bucay, Rio Chagüe .

Other localities. ECUADOR: Guayas prov., ca 8 km N of Cumandá, 723 m, Comunidad Shuar, S 02°08´24´´, W 79°07´06´´ ; ECUADOR: Guayas prov., ca 7 km N of Cumandá, 680 m, Comunidad Shuar, 02°08´43´´, W 79°07´17´´ .

Redescription. Body ( Figs 15, 22 ) small to medium-sized, 10.4‒13.6 mm long, 4.3‒5.0 mm wide, dorsal surface of the head and pronotum shiny black, elytra shiny black, on apical part brown-black.

Head ( Figs 16, 23 ) narrower than body, 2.9‒3.3 mm wide, concolorous with the rest of dorsal body surface, all parts of head glabrous except for two setae on both left and right borders of eyes and orbital plates.

Mandibles ( Figs 18, 25 ) ochre to reddish-brown, almost symmetrical, each mandible with 4 teeth, very narrow black stripe on periphery, more distinct on fourth teeth.

Labrum ( Figs 17, 24 ) similar in both sexes, thinly triangular, brown with dark brown-black basomedian area and basolateral margins, with protruding black basal part, longer (1.4‒1.8 mm) then wide (1.3‒1.5 mm), with 6‒8 lateral teeth on the margin and about 5‒9 anterolateral and 5‒7 lateral setae.

Labial and maxillary palpomeres yellow-ochre coloured with darker apical parts.

Antennae extend posterior past the elytral apex, antennomeres 1‒4 shiny brownish to blackish, antennomere 4 with yellow-brown basal third, antennomeres 5‒11 ochre-brown, dull and with fine setae.

Eyes large and protruding, deep longitudinal groove above the eyes with 2 setae.

Clypeus smooth, black, lateral margins brown-black.

Pronotum slightly longer than wide (mean: 2.75 mm long, 2.53 mm wide), converging slightly anteriad but strongly posteriad, lateral margins distinct and convex; anterior lobe distinctly wider than posterior lobe which is notably higher; surface of pronotal disc almost smooth, indistinctly wrinkled, anterior sulcus with less wrinkled groove than posterior one.

Mesepisternum with deep, pointed impression on the dorsal third of lateral margin in female (cuppling sulcus), while with sharp groove extending from the dorsal lateral margin to ventral lateral margin in male.

Elytra ( Figs 15, 22, 19, 26 ) elongate, lateral margins slightly expanded laterally, widest near the middle, narrower towards apex, more notably in male, length 8.0–9.0 mm, wide 4.3‒5.0 mm, ratio of length to width = 1: 0.54 in male and 1: 0.56 in female; surface flattened, almost uniformly shiny black except for brownish-black posterior area, deeply punctate on anterior area, yet punctures sparser and shallower on posterior area; elytral maculation consisting of one, yellow-ochre, almost circular central macula (approximately 1 mm in diameter) placed somewhat towards outer elytral margin; shoulders rounded with barely detectable basal and preapical umbones; elytral apex distinctly sexually dimorphic: in male with distinct, subacute, spine-like outer tooth, in middle deeply excised towards subacute sutural spine; elytral apex in female truncate in middle, with smaller subacute lateral tooth and indistinct sutural spine; the distance between the lateral tooth is ca 1.5 mm in male and ca 2.5 mm in female ( Figs 19, 26 ); membranous flight wings present.

Legs yellow-ochre, femora ochre-brown and black distally, metatibiae darker then protibiae and mesotibiae, tarsal segments usually slightly darkened distally, femoral surface covered with very sparse rather regular rows of erect ochre setae, tibial surface covered with denser irregular setae, more regular on protibiae; mesotibiae with denser setae distally, tarsi covered with denser and rather regular rows of erect ochre setae, second and third tarsomere with brush-like setal structure distally, more distinct on protarsi in female, while protarsi generally more setose in male.

Aedeagus ( Figs 20, 21 ) length 4.0‒ 4.4 mm, width 0.6 mm basal portion short, median portion moderately dilated distally, apical portion conically attenuated towards small, moderately ventrally directed apex, with knoblike tip.

Differential diagnosis. Oxycheila buestani Wiesner, 1999 ( Figs 15‒26 ) is obviously morphologically close to Oxycheila pseudostrandi Wiesner, 1999 ( Figs 27‒30 ) but is generally smaller (10.4‒13.6 mm) and clearly distinguished by the entire yellow-ochre legs and ochre-brown femora with black knees, labrum is triangular and brown. O. pseudostrandi is generally bigger (13.1‒14.2 mm), has completely black femora, yellow tibia and tarsi, the labrum is rather trapezoid and predominantly yellow coloured, and, particularly, the male elytral apex possesses longer, acute lateral spine ( Fig. 29 ). Moreover, the internal sac in the examined aedeagi appears different.

Figures

FIGURES 15‒26. Oxycheila buestani Wiesner, 1999. (15‒21 male, 22‒26 female). 15, 22: habitus; 16, 23: head; 17, 24: labrum; 18, 25: mandible; 19, 26: elytral apex; 20, 21: aedeagus male. Bars in mm.

FIGURES 27‒30. Oxycheila pseudostrandi Wiesner, 1999, male. 27: habitus; 28: head; 29: elytral apex; 30: aedeagus. Bars in mm.