Zetheumenidion latum, Selis, 2024

Selis, Marco, 2024, Revision of the Afrotropical genus Zetheumenidion Bequaert (Hymenoptera: Vespidae: Eumeninae), Zootaxa 5406 (1), pp. 37-65 : 49-54

Zetheumenidion latum sp. nov.

( Figs. 8 , 12 )

Diagnosis. Belonging to the group of species with subhorizontal face of propodeum and abruptly expanded base of T1, in which is recognized by lateral faces of propodeum shallowly concave, propodeal valvula longer than basally wide, T 1 in dorsal view markedly widened near base with width at level of spiracles greater than apical width, dorsal face of T1 flattened with a basal longitudinal furrow, apical lamella of T2 more strongly reflexed and reaching same height of preapical bulge ( Fig. 8D ).

Material examined. HOLOTYPE: ♂ labeled “ Ceres , / Cape Province / Nov. 1920. // S. Africa. / R.E.Turner. / Brit.

Mus. / 1920–497. // Eumenes / femoratus / A v. Schulth. // J.Bequaert det. // Zetheumenidion latum / HOLOTYPUS

♂ / Det. Marco Selis ” ( MSNVE). Description. Male holotype. Body length 12.4 mm; fore wing length 8.2 mm .

Head 1.3× as wide as long in frontal view ( Fig. 8B ). Clypeus as wide as long in frontal view, apical margin shallowly emarginate and about as wide as interantennal space, 0.35× as wide as width of clypeus, apical angles more or less right-angled, with rounded apex and slightly pointing out; clypeus in lateral view distinctly convex in basal two thirds and then shallowly depressed, disc of basal half bulging. Interantennal space with a barely recognizable longitudinal ridge, becoming sharp for a short distance above upper margin of antennal toruli. Distance from posterior ocellus to occipital carina 1.6× as long as the distance from posterior ocellus to inner eye margin; vertex in lateral view flattened and horizontal, deeply 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 2.5× as long as wide and 1.6× 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 apical fourth of F8; F4–9 with weakly developed tyloids, linear on F4–8 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 markedly separated from dorsal face. Mesoscutum 0.75× as long as wide in dorsal view, very weakly convex in lateral view. Scutellum weakly convex, anterior margin shallowly crenate on lateral fifths and deeply furrowed in the middle. Metanotum convex and nearly horizontal, 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, not 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 long and forming a subhorizontal dorsal face behind metanotum, deeply furrowed in the middle and steeply rounded into posterior face, but without any sharp delimitation; lateral face weakly depressed, more markedly above anterodorsal angle of propodeal valvula; posterior face subtriangular and shallowly depressed; all faces separated but not sharply, all carinae lacking; propodeal valvula distinctly longer than basally wide and apically rounded. T 1 in dorsal view 4.5× as long as apically wide, sides strongly diverging in basal fourth, then evenly concave, basal half more or less fusiform and wider than apical width of segment; T 1 in lateral view abruptly expanded in basal third and then narrowing to apex, forming a distinct basal hump; dorsal face of T1 flattened, with a short longitudinal furrow at summit of basal hump. T2 bell-shaped with basal petiole wider than long, preapical area strongly bulging and nearly sharp, apical lamella preceded by a costulate depressed area, then strongly reflexed and reaching same height of preapical bulge; T 2 in lateral view strongly convex behind basal petiole. S2 much less convex than T2, somewhat shallowly depressed in basal half, apical margin lamellate similar to T2, but preapical area shallowly bulging and rounded, and apical lamella shorter and much less reflexed. T3 with a somewhat decolorate apical margin, but not lamellate. T7 weakly and evenly concave on disc; S7 evenly rounded and wide, mostly flattened. Hind femur enlarged, in lateral view 2.6× as long as wide and with dorsal margin weakly convex and ventral margin strongly convex with sinuate base, ventral face with an obliquely depressed elliptical area in basal half and a centrally placed spine-bearing pore ( Fig. 8C ).

Clypeus shallowly punctured, each puncture having a central deep pore from which a seta arise, interspaces narrower on disc and becoming wider on margins. 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 finely micropunctate; area along occipital carina densely crenate. Mesosoma with deep punctures larger than those on vertex, interspaces flattened and reaching up to one puncture diameter on pronotum, mesoscutum, scutellum and metanotum, narrower and convex on mesepisternum and dorsal faces of propodeum. Tegula shiny with few sparse large punctures. Metaepisternum with fine transverse striae on upper plate, sparse deep punctures on lower plate. Posterior face of propodeum with mixed punctures and irregular transverse striae; lateral face with dense and fine but strong striation, with few small punctures mixed. T1 with small deep punctures, interspaces ranging from half to several puncture diameters, very finely and shallowly shagreened on base and on sides, densely and finely micropunctate on flattened part of dorsal face. T2 densely shagreened with very fine micropunctures intermixed, macropunctures barely visible basally and becoming progressively larger and deeper apically, with a series of coarse punctures in front of the preapical bulge. T3–7 shagreened with very fine micropunctures, T7 with few sparse punctures. S2 shinier than T2, subdepressed basal part more strongly shagreened than rest of surface, punctures deep and sparse and becoming progressively stronger apically. S3–7 similar to respective tergites, S7 with dense small fine punctures. Outer face of hind femur shiny with few very sparse deep punctures, interspaces with very weak shagreen and very sparse barely visible micropunctures. Frons with long golden setae, longer than ocellar diameter; clypeus, gena and mesosoma with shorter pale setae, long and fine on sides of propodeum; 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: suffused markings on scape, apical third of mandible, dorsal face of pronotum, tegula, parategula, posterior half of scutellum (suffused with yellow), rounded spot on upper plate of mesepisternum, margins of yellow spots on propodeum, longitudinal lines on sides of T1, basolateral spots and suffused preapical margin on T2 and S2; following parts yellow to yellowish-orange: clypeus except narrow lateral margins of basal half, scape except dorsal face, basal two thirds of mandible, inner eye margin up to ocular sinus, narrow anterior margin of pronotum, anterior spot on tegula, most of metanotum, large spots covering posterior half of dorsal faces of propodeum, posterior margin of spot on mesepisternum, narrow 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; flagellum basally ferruginous and gradually turning to black towards apex, F6–F10 with contrasting ivory spots on ventral face; legs mostly pale ferruginous, with pale yellow markings on lower face of mid and hind coxae, outer face of fore and mid femora, and outer face of all tibiae, hind femur brownish-black and turning to dark reddish-brown on inner face, apex weakly ferruginous. Wings infuscate and brownish, with weak purplish reflections.

Female. Unknown.

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

Etymology. The species epithet refers to the wide T1 of this species.

Notes. This species and Z. abruptum are closely related, being generally similar to each other and sharing the subhorizontal dorsal face on propodeum and the abruptly expanded base of T1, but are readily distinguished by the characters listed in the identification key; in addition, the aedeagus in Z. latum is much more apically expanded than in Z. abruptum ( Fig. 12 ). Given the small number of specimens available, it is not excluded that these two taxa represent just variations of the same species, but the differences both in external and genital morphology are constant and support the recognition of two distinct species for the time being.

Figures

FIGURE 8. Zetheumenidion latum 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 12. Male genitalia of Zetheumenidion species: aedeagus in ventral view, aedeagus in lateral view and digitus + volsella.

FIGURE 13. Distribution maps of Zetheumenidion species.