Zetheumenidion minimum, Selis, 2024

Selis, Marco, 2024, Revision of the Afrotropical genus Zetheumenidion Bequaert (Hymenoptera: Vespidae: Eumeninae), Zootaxa 5406 (1), pp. 37-65 : 54-56

Zetheumenidion minimum sp. nov.

( Fig. 9 )

Diagnosis. Recognized by the following combination of characters: male clypeus longer than wide with emarginate apical margin ( Fig. 9B ), flagellomeres proportionally longer and male F1 2.6× as long as wide, dorsal side of mesosoma not forming an even surface, pronotal carina evenly developed for whole length, anterior margin of pronotum straight, mesepisternum with large punctures, propodeum with mid-line strongly convex in dorsal half and sides bulging above valvula, T1 not expanded basally and of same height for whole length, apical lamella of T2 weakly reflexed and reaching height of preapical swelling ( Fig. 9D ), male hind femur shiny and not shagreened on outer face ( Fig. 9C ).

Material examined. HOLOTYPE: ♂ labeled “ CAPE PROVINCE / Howison’s Poort / Grahamstown / 25-XII-1967 / C. Jacot-Guillarmod // Zetheumenidion minimum / HOLOTYPUS ♂ / Det. Marco Selis ” ( MSNVE).

Description. Male holotype. Body length 10.0 mm; fore wing length 7.0 mm.

Head 1.3× as wide as long in frontal view ( Fig. 9B ). Clypeus 1.2× as long as wide in frontal view, apical margin emarginate and wider than interantennal space, 0.4× as wide as width of clypeus, apical angles more or less right-angled, with rounded apex and slightly pointing out; clypeus in lateral view weakly convex in basal half and then shallowly depressed. Interantennal space bluntly tuberculate above. Distance from posterior ocellus to occipital carina 1.9× as long as the distance from posterior ocellus to inner eye margin; vertex in lateral view flattened, shallowly furrowed along occipital carina; gena as wide as eye at bottom of ocular sinus; occipital carina complete, strong and shortly lamellate for whole length, more highly lamellate at angle formed at level of antennal insertions. F1 2.6× as long as wide and 1.65× as long as F2; F2–4 distinctly longer than wide; F5–9 subquadrate to weakly transverse; F11 subconical and weakly curved at base, with strongly flattened apical half, reaching apex of F8; F3–9 with weakly developed tyloids, linear on F3–8 and wide on F9. Mesosoma in dorsal view 1.2× as long as wide. Pronotum in dorsal view with converging sides; pronotal carina complete, forming a sharp translucent lamella on dorsal face; humeri rounded, obtuse in dorsal view; lateral faces short and smoothly passing into dorsal face. Mesoscutum 0.8× as long as wide in dorsal view, weakly convex in lateral view. Scutellum almost flat, anterior margin shallowly crenate on lateral fifths and deeply furrowed in the middle. Metanotum barely convex and weakly oblique, weakly produced in the middle of the posterior margin. Tegula with strongly convex surface and outer margin, maximum width near middle, posterior lobe right-angled and sharp, almost equaling parategula; parategula oblique and nearly straight in dorsal view, strongly flattened and forming a sharp vertical lamella. Mesepisternum strongly convex, sharply separated from epicnemium but without epicnemial carina. Propodeum oblique and strongly convex in dorsal half, but not forming a subhorizontal dorsal face behind metanotum, shallowly furrowed in the middle; lateral face depressed, forming a deep pit above anterodorsal angle of propodeal valvula; posterior face subtriangular and concave above orifice; transition between dorsal and lateral faces angled, but without lateral carina; propodeal valvula longer than basally wide. T 1 in dorsal view 4.7× as long as apically wide, sides weakly diverging in basal third, then nearly straight, width at level of spiracles equal to apical width; T 1 in lateral view weakly and evenly expanded in basal fourth, then of regular height to apex; dorsal face of T1 narrowly flattened on disc. T2 bell-shaped with basal petiole slightly wider than long, preapical area strongly bulging and nearly sharp, apical lamella preceded by a costulate depressed area, then strongly reflexed and reaching height of preapical bulge; T 2 in lateral view strongly convex behind basal petiole. S2 much less convex than T2, apical margin lamellate similar to T2, but preapical area shallowly bulging and rounded, and apical lamella shorter and very weakly reflexed. T3 with a somewhat decolorate apical margin, but not lamellate. T7 evenly flattened on disc; S7 evenly rounded and wide, mostly flattened. Hind femur enlarged, in lateral view 2.85× as long as wide, dorsal margin weakly convex basally and then straight to apex, ventral margin bulging in the middle and strongly sinuate basally, ventral face with an obliquely depressed elliptical area in basal half and a centrally placed spine-bearing pore ( Fig. 9C ).

Clypeus shallowly punctured, each puncture having a central deep pore from which a seta arise, interspaces everywhere much wider than puncture diameter. Head very deeply and densely punctured, punctures smaller on frons and becoming larger and slightly sparser on vertex, interspaces narrower than puncture diameter and convex and shiny; gena more sparsely punctured, interspaces shiny; area along occipital carina imperceptibly crenate. Mesosoma with deep punctures larger than those on vertex, interspaces flattened and reaching up to half puncture diameter on pronotum, mesoscutum, scutellum and metanotum, few isolate smooth areas reach one puncture diameter; mesepisternum and dorsal faces of propodeum with smaller but irregular punctures, some arranged in irregular series. Tegula shiny with few sparse large punctures. Metaepisternum with few coarse striate mixed with basal fine striation on upper plate, sparse deep punctures on lower plate. Posterior face of propodeum with very coarse punctures mixed with irregular transverse striation; lateral face with dense and fine but strong striation, with few small punctures mixed, striae disappearing around apical pit. T1 with small deep punctures, interspaces ranging from half to several puncture diameters, very finely and shallowly shagreened on base and on sides, shallowly shagreened and sparsely and finely micropunctate on disc. T2 finely shagreened and silky-shiny, macropunctures barely visible basally and becoming progressively larger and deeper apically, with a series of coarse punctures in front of the preapical bulge, denser in the middle. T3–7 shagreened with very fine micropunctures, T7 with few sparse punctures. S2 weakly shinier than T2, punctures deep and sparse and becoming progressively stronger apically. S3–7 similar to respective tergites, S7 with sparse fine punctures. Outer face of hind femur shiny, with few very sparse shallow punctures, interspaces nearly entirely smooth and without microsculpture. Frons with long pale setae, about as long as one ocellar diameter; clypeus, gena and mesosoma with shorter pale setae; sides of propodeum with dense fine whitish setae; metasoma with very short brownish pubescence, short erect setae at base of T1 and at apex of S2–6, S7 with longer darker setae forming a sparse preapical brush.

Black; following parts ferruginous-red: most of mandible, irregular markings on scape, anterior half and posterior corners of dorsal face of pronotum, tegula, posterior half of scutellum, posterior half of dorsal faces of propodeum, small spot on upper plate of mesepisternum, longitudinal lines on sides of T1, basolateral spots on T2 and S2; following parts yellow to yellowish-orange: scape except dorsal face, basal triangle of mandible, narrow margin in ocular sinus, narrow anterior margin of pronotum, anterior spot on tegula, most of metanotum, narrow and interrupted apical band on T1, bisinuate apical band on T2 partly covering apical lamella, sinuate apical bands on T3–6, regular narrow apical band on S2, irregular suffusions on S3–6; labrum and clypeus ivory-yellow, clypeus with narrow black lateral margins; flagellum ferruginous in basal half and turning to black towards apex, F6–F10 with contrasting ivory spots on ventral face (weak and suffused on F6–7); legs mostly pale ferruginous, with ivory markings on lower face of mid and hind coxae, outer face of fore and mid femora, outer face of all tibiae, and outer face of fore and mid basitarsi, hind femur dark brown in basal half and turning to ferruginous in apical half. Wings fusco-hyaline.

Female. Unknown.

Distribution. South Africa: Eastern Cape ( Fig. 13 ).

Etymology. The species epithet refers to the small size of this species.

Note. The holotype’s genitalia were missing and could not be located in Giordani Soika’s collection.

Figures

FIGURE 9. Zetheumenidion minimum sp. nov., male. A, habitus in dorsal view. B, head in frontal view. C, hind femur in lateral view. D, metasoma in lateral view.

FIGURE 13. Distribution maps of Zetheumenidion species.