Antodynerus dictatorius ( Giordani Soika, 1935 ) Selis, 2020

Selis, Marco, 2020, On generic placement of Odynerus dictatorius Giordani Soika and its mimicry ring (Hymenoptera: Vespidae: Eumeninae), Zootaxa 4845 (1), pp. 83-96 : 84-87

Antodynerus dictatorius ( Giordani Soika, 1935) comb. nov. ( Figs. 1–7 , 15 )

Odynerus dictatorius Giordani Soika 1935: 247 , fig. 2, ♀, ♂ (in subgenus Rhynchium )—“Transvaal: Welgegund” (lectotype female SDEI).

Diagnosis. Recognized by the following combination of characters: female clypeus with narrow apical emargination ( Fig. 2 ), cephalic foveae placed in a subtriangular shallow depression ( Fig. 3 ), male clypeus broader than long and semicircularly emarginate ( Fig. 4 ), F11 digitiform and evenly curved ( Fig. 5 ), pronotal carina complete and rounded on humeri, transverse carina of metanotum arcuate and dull, posterior lobe of tegula long and narrow ( Fig. 6 ), posterolateral corners of propodeum with short tubercles, apical margin of T1 translucent, T2 with apical reflexed lamella, T3 of male with short translucent lamella ( Fig. 7 ), coloration black and orange, with apical band on T2 narrow medially and abruptly expanded on sides.

Material examined. SOUTH AFRICA: Capland , Algoa Bay, 29.III.1896, leg. Dr. Brauns, 1♀ ( MSNVE); CP., Matatiele, 26.II.1953, 1♂ ( MSNVE); S. Africa, Lady Grey, 12.II.1925, leg. R . I. Nel, 1♀ ( MSNVE); Transvaal , Johannesburg, I.1906, leg. G. Kobrow, 1♂ ( MSNVE) .

Description. Female ( Fig. 1 ). Body length 10.8-12.2 mm; fore wing length 10.0- 11.2 mm.

Head in frontal view 1.2 × as wide as long ( Fig. 2 ). Clypeus in frontal view as wide as long, basal margin bisinuate, weakly emarginate in the middle, lateral margins of free apical area straight and converging below, apical margin emarginate, emargination 0.25 × as wide as clypeus width and 3.5 × as wide as deep, narrower than interantennal distance, apical teeth subtriangular with rounded apex weakly pointing outwards, bluntly and very shortly carinate; clypeus in lateral view evenly convex, weakly depressed apically. Interantennal space with irregular longitudinal carina; area above interantennal space convex with a barely developed tubercle in ventral third. Distance from posterior ocellus to occipital margin 1.5 × as long as distance from posterior ocellus to inner eye margin. Cephalic foveae very small, distance between foveae about twice as their diameter, placed in a wide subtriangular depression which is shallower on sides and deeper in the middle, posterior margin of depression weakly raised in the middle ( Fig. 3 ). Gena in lateral view 1.15 × as wide as eye at bottom of ocular sinus. Occipital carina complete, lower on vertex, lamellate on gena. Antennal scape 3 × as long as apically wide, F1 1.75 × as long as wide, shorter than F2+F3, F2–F3 weakly longer than wide, F4–F5 subquadrate, F6–F9 wider than long, F10 bullet-shaped and weakly longer than basally wide. Mandible 5-toothed, in frontal view apical tooth longer than basally wide and nearly straight, second and third teeth forming elongate cutting margins with raised apex, fourth tooth shortly triangular, fifth tooth reduced to short tubercle. Maxillary palpi 6-segmented, basal three palpomeres elongate and cylindrical, apical three palpomeres smaller, combined as long as previous palpomere; labial palpi 4-segmented, first palpomere elongate and cylindrical, bearing three long preapical setae, second palpomere cylindrical with very sparse short setae and a pair of asymmetrical long curved setae apically, outer seta longer, third palpomere elongate and weakly expanded apically, with a pair of long curved setae at apex, fourth palpomere digitiform, shorter than apical setae of preceding palpomere. Mesosoma elongate in dorsal view, 1.3 × as long as wide. Pronotum in dorsal view with nearly straight sides, pronotal carina complete and shortly lamellate dorsally, evenly rounded on humeri, pretegular carina strong. Mesoscutum in dorsal view 0.9 × as long as wide between tegulae, raised on anterior third of median line, notauli very shallow and short, mesoscutum evenly convex in lateral view; parategula short, right angles basally. Scutellum wider than long, 0.6 × as wide as mesoscutum, anterior margin crenate; nearly flattened in lateral view and about on same level of mesoscutum; axillary fossa small and narrow. Metanotum in lateral view angled, with separation between faces not sharp; horizontal face semicircular in shape, dull transverse carina arcuate and denticulate, interrupted medially, vertical face transversely convex. Tegula broadly rounded on outer margin, maximum width reached in anterior half, outer margin weakly reflexed, posterior lobe triangular, long and narrow and exceeding parategula, inner margin of posterior lobe placed below tegula ( Fig. 6 ). Mesepisternum convex, epicnemial carina blunt and visible only in ventral half, epimeron produced anteroventrally. Propodeum in posterodorsal view wider than long, dorsal faces sloping and weakly convex, forming an unique surface with posterior face, posterior face broadly and shallowly concave, lateral faces flattened dorsally and concave below; dorsal and lateral carina absent, though separation between dorsal and lateral faces distinct, inferior carina sharp and short, posterolateral angles with short flattened tubercle, median line of concavity with sharp carina on lower two thirds, replaced by a narrow and deep fovea on upper third. T 1 in dorsal view 1.95 × as wide as long, subtruncate anteriorly, apical margin forming a translucent lamella; T 2 in dorsal view 1.25 × as wide as long, evenly convex at sides, apically with a reflexed translucent lamella, about as long as lamella on T1 medially and becoming shorter laterally, not reaching lateral margins of tergum, T2 evenly convex in lateral view and weakly depressed subapically; S1 with an arched transverse carina near base of expanded part, apical expanded part much wider than long and with rounded extreme sides; S 2 in lateral view evenly convex, with broad and shallow depression on basal half.

Clypeus with sparse small deep punctures, interspaces much larger than punctures diameter and densely micropunctate basally, longitudinally microreticulate-striate in rest of surface, extreme apex unsculpted and shiny. Head with small deep punctures, arranged in irregular transverse series, interspaces irregular in length and with some sparse micropunctures on frons; area along occipital carina on vertex impunctate, very finely microreticulate; gena with larger and denser punctures along eye margin. Scape densely micropunctate with very sparse fine macropunctures. Dorsal and lateral faces of pronotum densely punctured, punctures deep and coarse, interspaces much narrower than punctures diameter and reduced to narrow ridges, becoming larger and flattened near posterior margin, anterior face of pronotum shiny and smooth in the middle, microreticulate on sides. Mesoscutum and scutellum similar to frons, but punctures larger and interspaces wider and more micropunctate. Dorsal face of metanotum coarsely punctured, interspaces very narrow and reduced to irregular ridges; posterior face of metanotum microreticulate with coarse punctures dorsally. Tegula densely micropunctate and with fine macropunctures. Proepisternum shiny and micropunctate, interspaces larger than micropunctures. Mesepisternum punctured similar to pronotum, but interspaces on dorsal half forming elongate ridges, transverse sulcus with strong ridges; epicnemium microreticulate with some deep punctures ventrally. Dorsal plate of metaepisternum with fine irregular transverse striae and some deep punctures dorsally; ventral plate dull and microreticulate, with sparse shallow punctures. Dorsal faces of propodeum coarsely punctured, interspaces very narrow and ridge like, anterolateral corners with a transversely striated area; posterior face obliquely striate and with some sparse deep punctures; lateral faces with very dense fine transverse striae and sparse deep punctures. T1 microreticulate on anterior vertical face, posterior horizontal face with small punctures, interspaces much larger than punctures diameter and microreticulate; T2 with small deep punctures, interspaces much larger than punctures diameter on disc, becoming much shorter on sides and apically; T3–T5 microreticulate, with fine sparse punctures; T6 densely micropunctate. S1 with area in front of arched carina dull and microreticulate, area behind carina shiny with coarse and irregular sculpture; S2–S6 similar to respective terga, but punctures sparser and deeper, interspaces on S2 shiny. Pilosity pale, whitish-yellow; vestiture of head and mesosoma made of erect setae, some setae on vertex and dorsal face of mesosoma and most of setae on mesepisternum apically bent; clypeus with sparse short pubescence; posterolateral corners of propodeum with much longer setae; metasomal pubescence dust-like, with long setae on S1 and sparse short setae on S2–S5.

Black; following parts orange: clypeus, bilobate spot above interantennal space, elongate spot on upper third of gena, mandible except inner margin, antenna with F5–F10 infuscate above, dorsal face of pronotum, apex of parategula, tegula, legs after base of femora, dorsal face of T1 except broad median emargination, apical band on T2 narrow in the middle and abruptly expanded on sides, almost reaching basal margin, apical band on T3 narrow medially and abruptly expanded on sides, T4–T6 entirely, narrow apical band on S2–S5, apical half of S6. Wings light amber with golden reflections in basal half, weakly infuscate with weak purplish reflections in apical half, costal vein bright orange.

Male. Body length 10.7 mm; fore wing length 9.4 mm.

Like female, differing as follows: head in frontal view 1.2 × as wide as long, clypeus in frontal view 1.1 × as wide as long, free apical part much shorter than basal interocular part, apical margin semicircularly emarginate and 0.3 × as wide as clypeal width ( Fig. 4 ), clypeus in lateral view more convex in basal two thirds, mandible 3-toothed with apical tooth straight and longer than wide, second tooth prolonged in a long cutting margin that occupies about half of inner margin, third tooth subtriangular, short with a very broad base, upper margin adhering to lateral margin of clypeus, F11 digitiform and evenly curved in lateral view, reaching apical third of F8 ( Fig. 5 ), gena in lateral view 1.4 × as broad as eye at bottom of ocular sinus, T3 with short apical translucent lamella ( Fig. 7 ); clypeus, ventral side of scape and broad marking above interantennal space bright yellow, transverse band on metanotum and longitudinal line on posterolateral corners of propodeum orange.

Aedeagus as in fig. 15.

Distribution. South Africa: North West, Eastern Cape, Gauteng, Western Cape?.

Notes. This species was placed in Knemodynerus by Gusenleitner (2012) due to the elongate tegulae and absence of parategulae, but examination of other specimens and comparison with a picture of the lectotype showed that even if the posterior lobe of the tegulae is elongate, the parategulae are not covered by the tegulae. Also, the semicircular shape of the metanotum is typical of Antodynerus , therefore Odynerus dictatorius is moved to this genus.

The typical series of this species comprises specimens collected in the North West (lectotype) and Western Cape (paralectotypes) of South Africa. Almost all specimens examined in this work were found in Giordani Soika’s collection identified as Odynerus dictatorius , implying that he was not aware of the differences between the species involved in this mimicry ring, therefore we cannot be sure whether the typical series is composed of dictatorius only or comprehends more species, especially in view of the strong similarity between dictatorius and imitator . The only specimen whose specific attribution is secure is the lectotype for obvious reasons. This specimen is from Welgegung, in North West Province, not far from Johannesburg, where a male specimen was collected. All paralectotypes were collected in Western Cape, the typical locality of Antodynerus imitator , and the description of male in the original description ( Giordani Soika 1935) seems to better fit A. imitator than A. dictatorius . I suspect this could be a case of vicariance, with Antodynerus dictatorius in the eastern part of South Africa and Antodynerus imitator in the western part. For this reason, presence of this species in Western Cape Province is considered doubtful.

Figures

FIGURES 1–7. Antodynerus dictatorius (Giordani Soika, 1935). 1–3, 6, ♀. 4–5, 7, ♂. 1, Habitus in dorsal view. 2, 4, Head in frontal view. 3, Head in dorsal view. 5, F5–F11 in lateral view. 6, Tegula in dorsal view. 7, T2–T3 in dorsal view.

FIGURES 15–16. Aedeagus in ventral and lateral view. 15, Antodynerus dictatorius (Giordani Soika, 1935). 16, Antodynerus imitator Selis, sp. nov.