Alastor (Alastor) brevicornis Selis, 2020

Selis, Marco, 2020, Notes on the Afrotropical species of Alastor Lepeletier (Hymenoptera: Vespidae Eumeninae), with description of nine new species, Zootaxa 4822 (3), pp. 361-388 : 362-365

Alastor (Alastor) brevicornis Selis , sp. nov.

( Figs. 1–5 , 43 )

Diagnosis. This species is immediately recognized by the shape of pronotum, with pronotal carina developed in rectangular lobes on humeri ( Fig. 4 ). Other characters useful to recognize it are: short antennae with F2–F9 subquadrate or wider than long, F11 small and strongly convex dorsally ( Fig. 3 ), apical margin of clypeus rounded out ( Fig. 2 ), fourth mandibular tooth much larger than third one, sides of propodeum rounded with dull apical teeth, T1 hemispherical in dorsal view and 2 × as wide as long, T2 basally convex in lateral view, T3 large with rounded-out apical margin ( Fig. 5 ), T7 subtruncate apically.

Material examined. Holotype, ♂, labeled “ Sunday river / Capland / Dr. Brauns / 16 (indecifrable letter) 9 // PARATYPUS / Alastor / brevicornis // Alastor (A.) brevicornis / Selis, sp. nov. / HOLOTYPUS ♂ / Det. Marco Selis 2018” ( MSNVE).

Description. Holotype, male ( Fig. 1 ). Body length 8.3 mm; fore wing length 6.8 mm.

Head in frontal view 1.2 × as wide as long ( Fig. 2 ), in dorsal view broader than mesosoma. Clypeus in frontal view 1.3 × as wide as long, dorsal margin broadly convex, lateral margin of free apical part straight and converging below, apical margin weakly rounded out and narrower than interantennal space; clypeus in lateral view strongly convex. Interantennal space flattened. Vertex long, distance from posterior ocellus to occipital margin 1.95 × as long as distance from posterior ocellus to inner eye margin; gena in lateral view 0.9 × as long as width of eye at bottom of ocular sinus; occipital carina complete, finer dorsally and lamellate ventrally, bent at height of lateral lobes of clypeus. Scape 3 × as long as apically wide; F1 1.75 × as long as wide; F2–F4 weakly longer than wide; F5–F10 subquadrate, weakly but distinctly convex above in lateral view; F11 small and barely reaching base of F9, apically rounded in dorsal view, strongly convex above in lateral view ( Fig. 3 ). Mandible 5-toothed, third tooth short and weakly pointed, fourth tooth large and triangular; carinae on outer face strong and lamellate. Mesosoma in dorsal view 1.4 × as long as wide. Pronotal carina complete, though confused with the punctures in the middle of dorsal face, strongly lamellate on humeri where it forms subquadrate lobes ( Fig. 4 ); humeri in dorsal view strongly pointed; transition from dorsal to lateral faces of pronotum smoothly rounded; pretegular carina strong and complete. Mesoscutum in dorsal view 1.1 × as wide as long; evenly convex in lateral view. Scutellum weakly oblique, distinctly flattened on disc and smoothly passing on metanotum, which is entirely flattened. Mesepisternum broad and convex, epicnemial carina absent. Propodeum in dorsal view short and broad, with lateral margins straight, then with a rounded excision just before the apical teeth; median depression of posterior face broad and moderately deep, with a large median triangular area which is incomplete below; in lateral view with dorsal margin angled in the posterior half and apical teeth pointing upward; apical teeth slightly depressed dorsoventrally, broad and with rounded apex. Tegula broader in anterior half, outer margin strongly rounded anteriorly and more weakly posteriorly, posterior lobe pointing toward middle and apically rounded. T 1 in dorsal view hemispheric, 6 × as broad as long; strongly convex in lateral view, with broad but shallow preapical furrow. T 2 in dorsal view 1.2 × as wide as long, almost parallel-sided, with a pair of shallow humps near apical margin; T 2 in lateral view convex in basal half and then flattened to apex. T3 large with convex apical margin ( Fig. 5 ). T7 subtruncate at apex. S2 slightly longer than T2, in lateral view weakly convex at extreme base and then flattened. S7 flattened, with raised lateral margins.

Clypeus smooth and shiny, with sparse shallow punctures, larger in the basal half and disappearing apically, interspaces much larger than punctures diameter. Mandibles smooth, with some deep punctures in the basal triangular area. Frons, vertex and gena with dense deep punctures, interspaces irregular and shiny, much shorter than punctures diameter. Scape with small deep punctures, interspaces smooth and equal to or larger than punctures diameter.Anterior face of pronotum smooth, with some indistinct punctures on dorsal and ventral margins; posterior half of dorsal face of pronotum with large deep punctures and narrow interspaces, punctures becoming shallower and sparser on humeri; lateral faces of pronotum irregularly striate and punctured. Mesoscutum with large deep punctures, interspaces larger in the middle and disappearing posteriorly, where punctures fuse with each other. Scutellum punctured like mesoscutum, except posterior margin which is unpunctured. Metanotum coarsely and irregularly punctured on anterior corners, smooth and shiny on the rest of surface. Proepisternum sparsely punctured. Mesepisternum with deep punctures, denser on dorsal half where they form irregular oblique series and becoming sparser ventrally, interspaces very narrow and opaque dorsally, becoming larger and shiny ventrally; epicnemium microreticulate with some punctures. Metaepisternum microreticulate and weakly shiny, with some deep punctures on upper margin of dorsal plate, ventral plate with sparse small deep punctures. Dorsal faces of propodeum with large and deep flat-bottomed punctures, interspaces very irregular and shiny; median depression of propodeum mostly smooth and shiny, with some shallow punctures on sides and very fine microreticulation near apical teeth; lateral faces of propodeum punctured like dorsal faces on dorsal margin, punctures becoming smaller and sparser ventrally. T1 impunctate on anterior vertical face, horizontal face with shallow oblique punctures, interspaces much larger than punctures diameter, punctures not reaching apically, therefore a broad impunctate apical border is formed. T2 with deep oblique punctures, which disappear basally and become very fine on yellow apical band; interspaces large basally and in the middle, becoming shorter on extreme sides and apex. T3 with deep oblique punctures, interspaces shorter than punctures diameter, larger on apical yellow band. T4–T7 microreticulate and weakly shiny, with indistinct very sparse punctures. S1 with deep and dense punctures, interspaces shiny and shorter than punctures diameter. Basal plate of S2 densely reticulate, basal transverse furrow with regular longitudinal carinae, S2 punctured similar to respective tergum but punctures deeper and interspaces larger and shinier. S3–S6 microreticulate and opaque, with sparse indistinct punctures. S7 smooth and shiny, with sparse moderately deep small punctures, lateral raised areas with very fine dense punctures. All coxae with deep punctures, interspaces shiny and about as large as punctures diameter.

Head, pronotum, mesoscutum, scutellum and metanotum with long brownish setae. Clypeus, interantennal area, lower half of gena, propodeum and sides of mesosoma with dense short silvery setae and sparser longer silvery ones. Metasoma with very short silvery setae on anterior part of T1, on T4–T7 and sterna; T1–T3 with dust-like silvery pubescence.

Apical part of aedeagus in ventral view parallel sided in basal fourth, then fusiform and tapering to a dull point apically; in lateral view straight and parallel sided, with apical narrowed part digitiform and bent ventrally; basal half of ventral margin finely crenulate and with short lamella on inner side. Ventral lobe of penis valve low, forming an obtuse angle which smoothly continues on ventral margin of apical part of aedeagus. Basal plate of aedeagus very short, nearly absent. Basal apodeme of aedeagus in lateral view long and narrow, strongly curved apically, with tubercle on ventral margin of basal half; basal apodemes in ventral view diverging in basal third, then converging, tubercle placed on transition from divergent and convergent parts ( Fig. 43 ). Distal lobe of digitus long, subtriangular with rounded apex; basal lobe of digitus short, rounded right angle, with reflexed inferior margin; ventral root of digitus long and pointed, with long rounded lobe on base of its dorsal margin. Short and sparse setae on most of digitus surface; tubercles forming a triangular area covering basal lobe and base of distal lobe. Volsella moderately setose, cuspis triangular and sharply pointed; inner sides of volsella with reflexed thick projection.

Black; following parts pale yellow: clypeus, broad band margining basal triangular area of mandible, spot at bottom of ocular sinus, anterior face of scape, large spots on humeri, anterior and posterior corners of tegula, regular apical band on T1, apical band on T2 weakly enlarged on sides, medially enlarged apical band on T3 not reaching sides, narrow and irregular apical margin on S1, bisinuate broad apical band on S2, apical spot on fore femur, irregular and barely visible marking on mid leg and hind tibia; following parts ferruginous: flagellum (infuscate above), posterior margin of pronotum, tegula, S1, legs; following parts dark red-brown: basal triangular area of mandible, scape, occipital margin, lower half of gena, underside of head, anterior face of pronotum in part, pronotal lobe, sides of mesosoma and most of propodeum, basal plate of S2, sides of S2, coxae, most of hind femur. Wings hyaline, weakly infuscate on costal margin and marginal cell.

Etymology. The specific name was found on a label pinned below the specimen, with Giordani Soika’s handwriting, and may refer to the short antennae or to the shape of pronotal carina.

Distribution. South Africa: Eastern Cape.

Figures

FIGURES 1–5. Alastor (Alastor) brevicornis Selis, sp. nov., ♂. 1, Habitus in dorsal view. 2, Head in frontal view. 3, Flagellum in lateral view. 4, Pronotal humerus in dorsal view. 5, T1–T3 in dorsal view.

FIGURES 43–48. Aedeagus in lateral and ventral view. 43, Alastor (Alastor) brevicornis Selis, sp. nov. 44, Alastor (Alastor) gestroides Selis, sp. nov. 45, Alastor (Alastor) moody Selis, sp. nov. 46, Alastor (Alastor) namibiensis Selis, sp. nov. 47, Alastor (Alastor) parilis Selis, sp. nov. 48, Alastor (Alastor) temperatus Selis, sp. nov.