Stenodynerus montanus Selis, 2024

Selis, Marco, Cilia, Giovanni, Wood, Thomas J. & Soon, Villu, 2024, Taxonomic revision of the Stenodynerus fastidiosissimus species-group in Western Europe and North Africa (Hymenoptera: Vespidae: Eumeninae), Zootaxa 5418 (1), pp. 34-56 : 45-48

Stenodynerus montanus Selis , sp. nov.

( Fig. 3B )

Diagnosis. This species can be recognized by the following combination of characters: gena 0.85–1.0 (♀) or 0.75– 0.85 (♂) × as wide as eye at bottom of ocular sinus, occipital carina shortly lamellate and not delimiting a furrow; parategula curved and pointing behind; lateral carinae of propodeum present, transition between dorsal and lateral faces marked by an irregular but distinct margin; scutellum black, T1–T5 with yellow bands. In female: apical margin of clypeus subtruncate; occipital carina of same height for whole length and almost straight; pronotal carina produced at extreme sides, pronotal humeri sharply right-angled in dorsal view; triangular lobes of submarginal carina entirely black or with a narrow yellowish margin, about 0.3× as long as the distance between their bases; disc of S2 sparsely punctured, punctures irregularly scattered and interspaces equal to puncture diameter; ocular sinus entirely black. In male: clypeus 0.9× as long as wide, apical teeth blunt and short, apical emargination 0.15–0.2× as deep as wide and with a broad translucent margin; F11 short and slim, reaching base of F 9 in lateral view, 2.8× as long as wide in dorsal view, not flattened, nearly circular in section; S2 sparsely punctured, interspaces wider than puncture diameter, except sometimes on posterior corners, punctures isolated and not forming series; apical part of aedeagus wide, maximum width 2.5× as wide as basal width of median apodeme; ventral lobes of aedeagus short and subtriangular in lateral view, right angled and pointing out, slightly diverging in ventral view; lateral apodemes sinuate in basal half but otherwise nearly straight.

Material examined. HOLOTYPE: ♂, labelled: “ MOROCCO Oukaimeden / alt. 2680m (pan trap) / 31°12’03”N 7°52’11”W / leg. V. Soon 12.05.2015 // TUZ / 034686 // OR292153 // Stenodynerus montanus / HOLOTYPUS ♂ / Det. Marco Selis” ( TUZ034686 , OR292153 ) . PARATYPES. MOROCCO: Marrakesh-Safi , Amroud , route to Sidi Chamarouch , 2300m, 31.1058 -7.9177, 10.VII.2022, leg. T.J. Wood, 1♀ ( OLML, OR292165 ) ; Marrakesh-Safi, Oukaimeden 1 km E, steppe, 2500m, 31.2091 -7.8423, 11.VII.2022, leg. T.J. Wood, 1♀ ( MSNVE, OR292155 ) ; Oukaimeden , 31.2059 -7.8590, 10.V.2015, leg. V. Soon, 1♂ 1♀ (♂ TUZ076195 , ♀ MSVI, OR292154 ) ; Oukaimeden , 2670m, 31.200833 -7.869722, 13.V.2015, leg. V. Soon, 1♀ ( TUZ616694 ) ; Oukaimeden , 2680m, 31.200278 - 7.87, 10.V.2015, leg. V. Soon, 1♂ ( MSVI) ; Pass NE Msenrir, 2400m, 3.VII.1987, leg. M. Schwarz, 1♀ ( OLML, OR292166 ) .

Description.

Male holotype. Body length 6.0 mm; fore wing length 6.3 mm. Head 0.8× as high as wide in frontal view, 1.9× as wide as long in dorsal view. Clypeus 0.9× as long as wide, apical margin shallowly emarginate and with a broad translucent lamellar margin, 0.3× as wide as width of clypeus, emargination 0.18× as deep as wide; apical teeth subtriangular and apically rounded, slightly pointing out, with weak and very short carina; clypeus in lateral view strongly convex in basal half, then flattened to the apex. Interantennal space sharply carinate and slightly bulging in upper part. Distance between posterior ocellus and inner eye margin as long as distance between posterior ocelli; distance between posterior ocellus and occipital carina 1.25× as long as distance between posterior ocellus and inner eye margin; ocelli disposed as an obtuse triangle, distance between posterior ocelli 2.0× as long distance between anterior ocellus and posterior ocellus. Gena 0.8× as wide as eye at bottom of ocular sinus, slightly depressed in lower half; occipital carina complete, on gena higher than on vertex and nearly straight. Scape 3.0× as long as apically wide; F1 1.6× as long as wide and 1.5× as long as F2; F2–F3 slightly longer than wide; F4–F5 subquadrate; F6–F8 shorter than wide; F9 longer than wide; F10 small and subquadrate; F11 digitiform, straight in dorsal view and slightly curved in lateral view, apically rounded, reaching base of F9; tyloids present on ventral surface of F8– F9 as indistinct areas with shinier surface. Mandible short and five-toothed, apical tooth longer and curved, second and third tooth subtriangular with rounded apex, fourth and fifth tooth almost fused and not distinct. Mesosoma in dorsal view 1.2× as long as wide. Pronotum in dorsal view with converging and sinuate sides, shallowly depressed just behind humeri; pronotal carina very shortly lamellate on lateral thirds of dorsal face, disappearing in the middle, higher on lateral faces of pronotum, especially in front of pronotal fovea; humeri slightly projecting, more or less right angled in dorsal view; anterior face of pronotum with widely spaced fine pits in median third; pretegular carina sharp in lower half and dull in upper half; dorsal and lateral faces of pronotum forming an even curve, lateral faces slightly depressed. Mesoscutum 0.9× as long as wide, distinctly convex in lateral view, notauli indicated near posterior margin. Scutellum slightly elevated over level of mesoscutum, barely convex in lateral view; anterior margin crenate, with ridges delimiting 10 pits, median ones being larger and deeper; axillary fossa large and circular. Metanotum nearly vertical, with a very short and flat dorsal face, smoothly passing posteriorly into posterior face. Tegula 1.3× as long as wide, outer margin strongly and evenly convex, posterior lobe pointed and pointing inward, equaling parategula; parategula curved and pointing behind, apically rounded. Mesepisternum convex; epicnemial carina reaching transverse furrow dorsally but not exceeding it, sharper just below furrow and disappearing ventrally. Propodeum short, falling directly below metanotum, lacking propodeal shelf, weakly oblique in lateral view; dorsal faces almost flattened and strongly sloping, distinctly separated from posterior face by hints of dorsal carina and sudden change in sculpture; lateral faces flattened with a deep depression just above propodeal valvula; posterior face with a basal rounded pit and a barely developed longitudinal carina in lower third; lateral carinae distinct and well-developed, though crenate by rough sculpture, almost lamellar on propodeal corners; submarginal carina produced in a short subtriangular lobe fused to propodeal valvula, flattened dorsoventrally. T 1 in dorsal view nearly semicircular, with broadly rounded anterior margin and short sub-parallel lateral margins, 1.9× as wide as long; in lateral view with a weakly convex vertical face and a barely depressed horizontal face, transition between faces almost right angled but rounded. S1 crescent shaped, very wide and short, with a high basal carina. T2 0.8× as long as wide in dorsal view, slightly wider at apex than at base, sides convex in basal third and then almost parallel-sided; in lateral view convex in basal half and flattened in apical half; apical margin finely crenate, with a short translucent lamella appearing between indentations. S2 nearly flattened in lateral view, weakly convex at extreme base. S7 flattened, with broad rounded apex.

Clypeus with very fine longitudinal microsculpture except on upper fifth, basal half with shallow punctures separated by their diameter or less, punctures becoming much sparser and partly forming shallow longitudinal furrows. Frons shiny with deep punctures, interspaces narrower than puncture diameter and weakly convex; interantennal space impunctate; ocular sinus with coarser and more irregular punctures; vertex similar to frons but interspaces narrower; gena densely punctate in upper half with coarse irregular interspaces, sparsely punctate and shiny in lower half. Scape shiny, densely micropunctate with sparse fine macropunctures. Mandible shiny and barely sculpted near teeth, matte in the rest of surface. Dorsal face of pronotum, mesoscutum and scutellum sculpted similar to vertex, but punctures larger and denser, some punctures arranged in irregular longitudinal series, punctures absent in the narrowest median part of pronotum; lateral faces of pronotum with finer punctures and strong transverse ridges; anterior face of pronotum mostly smooth, with scattered punctures in lateral thirds. Tegula shiny, with very sparse barely visible micropunctures and few scattered macropunctures not much larger than micropunctures. Metanotum with deep irregular punctures, interspaces narrow and convex, shining. Mesepisternum with deep large punctures, denser on epimeron and lower plate; dorsal plate with punctures separated and some flattened shining interspaces; epimeron and anterior two thirds of lower plate with punctures touching each other and forming irregular series, interspaces mostly reduced to irregular ridges; posterior third of lower plate with finer punctures and interspaces much larger than punctures. Metaepisternum matte; upper plate with strong striae and sparse punctures; lower plate irregularly microsculpted with sparse fine punctures and crenate anterior margin. Dorsal faces of propodeum very coarsely and densely punctured, interspaces reduced to sharp and irregular ridges; posterior face with fine deep punctures mixed with curved ridges, forming an irregular semicircular pattern connecting lower carinae of propodeum; lateral faces with punctures and striae mixed, punctures large and flat-bottomed in upper third, becoming smaller and deeper below. Vertical face of T1 matte and densely microsculpted, with sparse shallow oblique punctures in upper half; horizontal face of T1 with dense deep punctures, interspaces narrower than puncture diameter, some reduced to narrow ridges. T2 weakly shiny and micropunctate; on disc with deep oblique punctures arranged in transverse series, interspaces reaching up to two puncture diameters; area occupied by yellow band with larger and denser punctures; punctures on sides becoming sparser. T3–T6 micropunctate with shallow punctures, dense on T3 and becoming progressively sparser. T7 densely micropunctate. S1 with matte and shagreened basal petiole, apical enlarged part covered in longitudinal strong ridges. S2–S6 similar to respective tergites, but punctures larger and much sparser, interspaces up to several puncture diameters in length. S7 shiny with barely visible shagreen and dense very fine punctures. Head and mesosoma with yellowish setae, shorter than half ocellar diameter on vertex and mesosoma, equal to ocellar diameter on frons; clypeus with sparse very short setae, yellowish and appressed, mixed with barely visible whitish tomentum; corners of propodeum with long whitish setae; metasoma with very short, almost dust-like, pale tomentum, mixed with longer setae on S3–S7.

Black; following parts yellow: clypeus, mandible except teeth and apex, narrow line on lower half of inner eye margin not reaching bottom of ocular sinus, interantennal space connected to subquadrate spot, rounded spot behind dorsal lobe of eye, lower face of scape, broad band covering anterior half of pronotum and interrupted in the middle, tegula except brownish median spot, narrow line on parategula, metanotum except posterior margin, apical band enlarged on lateral thirds on T1, broad band enlarged on lateral fifths on T2, complete apical band on T3, laterally shortened apical bands on T4–T6, apical sinuate band on S2, spots on posterior corners of S3, spots on mid and hind coxae, most of femora except variable black basal area, tibiae and most of basitarsi; lower face of flagellum orange; tarsi ferruginous. Wings slightly infuscate, more strongly along costal margin.

Female. Body length 7.0 mm; fore wing length 6.0 mm. Similar to male but differing as follows: head 0.8× as high as wide; clypeus 0.95× as long as wide, apical margin subtruncate with right-angled lateral teeth, teeth shortly but strongly carinate; mandible longer and more robust, with sharper teeth; distance between posterior ocellus and occipital carina 1.2× as long as distance between posterior ocellus and inner eye margin, cephalic foveae very close and almost fused, placed in a deep shiny depression about as large as an ocellus and with a raised V-shaped posterior ridge; gena wider, as wide as eye at bottom of ocular sinus; F1 1.45× as long as wide, F2–F3 longer than wide, F4 subquadrate, F5–F7 transverse, F8–F9 subquadrate, F10 bullet-shaped and as long as basally wide; mesosoma more elongate, 1.35× as long as wide; mesoscutum less convex; scutellum flattened, on same level of mesoscutum; subtriangular lobes of submarginal carina longer, about 0.3× as long as distance between their bases; S2 more evenly convex from base to apex, not flattened after basal convexity; clypeus with more distinct longitudinal microsculpture and sparse elongate punctures, forming an irregularly ridged pattern.

Black; following parts yellow: basal arched band on clypeus, subquadrate spot above interantennal space, basal triangle of mandible, rounded spot behind dorsal lobe of eye, band covering anterior half of pronotum and interrupted in the middle, tegula except brownish median spots and black inner margin, parategula, metanotum except posterior margin, spots on dorsal faces of propodeum, spot on mesepisternum below tegula, broad apical band on T1 with medial deep incision, broad band on T2 with sinuate anterior margin, laterally abbreviated bands on T3–T4, median spot on T5, sinuate apical band on S2, spots on posterior corners of S3, fore and middle legs from middle of femur, hind leg from apex of femur; tarsi ferruginous; transition between black and yellow on femora with irregular reddish patches.

Variability. One of the male paratypes (TUZ076195) shows slightly paler markings and stronger sculpture of clypeus, but matches in all other diagnostic characters and was collected together with the holotype. Females from Oukaimeden are remarkably consistent, displaying only slight variation in the yellow pattern on clypeus and propodeum, with the latter having rounded yellow spots on the anterior half of the dorsal faces. The female from Sidi Chamarouch (OR292165) shows a richer yellow pattern, covering the basal half and on part of the apical half of the clypeus, the whole of the metanotum, and the dorsal faces of the propodeum; moreover, the clypeus appears more shining, but otherwise all diagnostic characters and genetic data match with the females from Oukaimeden.

Distribution. Morocco (High Atlas) ( Fig. 6A ).

DNA barcoding. COI-5P gene sequences were obtained from five specimens from three different localities of the High Atlas. The intraspecific sequence divergence of S. montanus is 0.00%. The species is clearly separated from the other taxa considered in this study and supported by a bootstrap value of 100 ( Fig. 6B ). The lowest interspecific genetic distance exists between S. montanus and S. difficilis , with a minimum of 23.86% (mean 25.85%).

Etymology. The specific name comes from the Latin adjective montanus , - a, - um (= mountain), in reference to the high altitude environment where the species was collected.

Figures

FIGURE 3. A, Stenodynerus laborans (Costa, 1882): habitus of male, habitus of female, head of male, head of female, flagellum of male, aedeagus in ventral and lateral view. B, Stenodynerus montanus Selis, sp. nov.: habitus of male, habitus of female, head of male, head of female, flagellum of male, aedeagus in ventral and lateral view.

FIGURE 6. A, distribution map of the Stenodynerus fastidiosissimus-group in Western Europe and North Africa; records out of the area considered in this study are omitted. B, phylogenetic tree (neighbor-joining) of the Stenodynerus fastidiosissimus-group based on the mitochondrial COI gene. Ancistrocerus gazella (Panzer) and three species belonging to other species-groups of Stenodynerus were used as outgroups. Numbers adjacent to branches represent bootstrap support (values of <75 are omitted).