Stenodynerus lombokensis Selis, 2019

Selis, Marco, 2019, A new species of Stenodynerus de Saussure, 1863 (Hymenoptera: Vespidae: Eumeninae) from Lombok, with a key to the species from the Malay Archipelago, Zootaxa 4624 (2), pp. 283-288 : 284-285

Stenodynerus lombokensis Selis , sp. nov.

( Figs 1–4 )

Material examined. Holotype, ♀, labelled “ Lombok / Sambalun 4000’ / April 1896 / H. Fruhstorfer // Stenod. / t1. angular // Giord. Ska. // Stenodynerus lombokensis / Selis, sp. nov. / HOLOTYPUS ♀ / Det. Marco Selis 2018” ( MSNVE).

Diagnosis. This species can be recognized by following combination of characters: vertex shallowly punctured, metaepisternum and lateral face of propodeum weakly shiny, T1 with irregular transverse fold but not distinctly carinate, T2 not reflexed apically, S2 with weak basal longitudinal furrow and strongly protruding basally, posterior horizontal face of T1 black with thin apical yellow band, and legs black and yellow.

Description. Female. Body length 8.6 mm; fore wing length 8.0 mm.

Head 1.1× as wide as long in frontal view ( Fig. 3 ). Clypeus in frontal view as long as wide, apical margin very shallowly emarginate, 0.25 × as wide as width of clypeus; apical teeth short and rounded, with short distinct carinae, area between carinae depressed; clypeus in lateral view weakly and evenly convex. Interantennal space with dull longitudinal carina. Distance from posterior ocellus to inner eye margin 0.6× as long as distance from posterior ocellus to occipital margin; ocelli disposed as an obtuse triangle, distance between posterior ocelli 2 × as long as distance between anterior ocellus and posterior ocellus. Foveae on vertex placed in a small shallow depression posteriorly margined by a fine and short carina. Temples 0.85 × as wide as eye at bottom of ocular sinus; occipital carina entire, stronger on lateral portions. Scape 3.2 × as long as apically wide; F1 1.5 × as long as wide; F2–F3 subquadrate; F4–F9 wider than long, becoming proportionally shorter towards apex; F10 bullet shaped, about as long as basally wide. Mesosoma in dorsal view elongate, 1.5 × as long as wide. Pronotum in dorsal view slightly narrowed anteriorly, lateral margins weakly sinuate; pronotal carina incomplete, present only on lateral faces and sides of dorsal face, anterior face smoothly passing into dorsal face; median foveae of anterior face very shallow, barely visible; pretegular carina weak on dorsal third. Mesoscutum 1.15 × as long as wide, evenly convex in lateral view, with traces of parapsidal furrows near posterior margin. Scutellum depressed, on same level of mesoscutum, anterior margin bearing a series of pits; axillary fossa small but distinctly rounded, as wide as long. Metanotum oblique, with a median deep pit on anterior margin. Tegula posteriorly broadened and equaling parategulae, outer margin straight on anterior third, then broadly rounded. Parategula short and curved. Mesepisternum convex, epicnemial carina short and present just below transverse furrow. Propodeum in lateral view oblique, straight from basal to apical margin; dorsal faces weakly convex, not distinctly separated from posterior face, which is broad and shallowly concave ( Fig. 4 ); lateral carinae absent, transiction from dorsal to lateral faces rounded; submarginal carina produced in a very short lobe. T 1 in dorsal view 1.45 × as long as wide, lateral sides weakly converging anteriorly; transiction from anterior vertical face to posterior horizontal face distinctly angled, but not produced in a transverse carina; anterior vertical face with a median longitudinal fold on dorsal half; T 1 in lateral view forming a nearly right angles, anterior vertical face a bit shorter than posterior horizontal face. T 2 in dorsal view longer than wide, sides convex and converging anteriorly; in lateral view depressed basally, then nearly flattened. S 2 in lateral view bulging basally, then flattened to the apex, basally with a shallow median furrow.

Clypeus shiny, with sparse large punctures which form irregular and shallow rugosities on disc of clypeus, interspaces large with some finer punctures. Head with dense deep punctures, interspaces about equal to punctures diameter, becoming wider in ocular sinus. Anterior face of pronotum entirely smooth, with some shallow punctures on extreme sides. Dorsal surface of pronotum and mesoscutum with punctures similar to head, but larger. Ventral corners of pronotum irregularly striate. Scutellum anteriorly with smaller and sparser punctures, becoming larger and denser posteriorly. Metanotum anteriorly smooth with some large punctures, posteriorly microreticulate and dull without punctures. Tegula shiny and smooth, with very fine indistinct punctures. Mesepisternum with deep punctures, larger anteriorly and becoming finer posteroventrally; interspaces one to three times punctures diameter. Metaepisternum dull and microreticulare, dorsal plate a bit shiny on middle. Dorsal faces of propodeum with large shallow flat-bottomed punctures, interspaces very narrow and reduced to irregular thin carinae; posterior face of propodeum dull and irregularly striate in the middle, microreticulate on sides; lateral faces of propodeum sculpted like metaepisternum, but with some large punctures on posterodorsal margin. Anterior vertical face of T1 impunctate and smooth, posterior horizontal face with dense deep punctures, which do not reach posterior margin, leaving a smooth apical margin. T2 with finer deep punctures, interspaces a bit larger than punctures diameter on middle and becoming larger on sides, punctures not reaching posterior margin. T3–T5 with shallow punctures, denser on T3. T6 densely micropunctate. S1 irregularly rugose. S2–S6 with punctures sparser than respective terga. Head and mesosoma with dense silvery short setae, T1–T2 with very sparse silvery bristles directed backward, T3–T6 and S2–S6 with dense very short pubescence, golden on terga and silvery on sterna.

Color. Black; following parts yellow: transverse basal band on clypeus, spot above interantennal space, anteroventral face of scape, basal spot on mandible, small postocular dot, short transverse lines on dorsal face of pronotum near mid line, anterior two thirds of metanotum, rounded spot below wing on mesepisternum, small spot on anterior and posterior corners of tegula, parategula, regular thin apical band on T1 continuing on lateral margins, thin apical band on T2 and S2, outer face of all tibiae; legs, tegulae and mandibles brownish-red; flagellum black above, dark orange below; wings nearly hyaline, brownish on anterior margin, venation reddish-brown.

Male. Unknown.

Distribution. Indonesia: Lesser Sunda: Lombok.

Etimology. The specific name refers to the provenance of this species, Lombok.

Notes. The genus Stenodynerus presents a pair of median pits on anterior face of pronotum, which in this species are reduced to a pair of shallow depressions. Despite the apparent lack of pits on pronotum, this species can be assigned to Stenodynerus due to the following characters: metanotum not tuberculate, submarginal carina of propodeum produced into pointed lamella, second submarginal cell not petiolate, metasoma sessile, T1 about as broad as T2, and T2 ridged basally below T1.

Following the key to Oriental species of Stenodynerus provided by Giordani Soika (1994), this species runs to couplet 5, where species with S2 weakly convex basally and bearing a longitudinal furrow are separated from species having S2 strongly protruding basally and without a longitudinal furrow. Neither option matches this specimen. This species shows S2 protruding at its base and with a weak median longitudinal furrow, apparently representing a transitional form between the two groups.

Figures

FIGURES 1–4. Stenodynerus lombokensis Selis, sp. nov., ♀. 1, Habitus in dorsal view. 2, Habitus in lateral view. 3, Head in frontal view. 4. Propodeum in posterior view.