Zethus (Zethus) intermedius Selis, 2018

Selis, Marco, 2018, Additions to the knowledge of solitary wasps (Hymenoptera: Vespidae: Eumeninae), with description of eight new species, Zootaxa 4403 (3), pp. 441-468 : 463-464

Zethus (Zethus) intermedius Selis , sp. nov.

( Figs. 45–51 )

Diagnosis. Following the key in Giordani Soika (1979) this species runs to couplet 2, where it shows intermediate characters between the two groups, with tegulae of the favillaceus group ( Fig. 48 ) and T1 and impressions on T3 of the pubescens group ( Fig. 50–51 ). This presence of characters from both groups is unique to this species.

Material examined. HOLOTYPE, ♂, pinned, “BANANKELEDAGA / C.BOBO-DIOULASSO / HAUTE- VOLTA 2.6.1968 / J. HAMON ORSTOM RÉC. / mimosee” [handwritten and printed on white label], “ Zethus sp. / Banankeladag. / Bobo. Dioul.” [handwritten on white label] ( MSNVE).

Description. Male. Body length 9.5 mm; fore wing length 7 mm.

Head 1.4× as wide as long in frontal view. Clypeus weakly convex in lateral view, apical margin broadly truncate, breadth of truncation about one third of clypeus breadth, lateral margins of truncation with very short blunt teeth, clypeus 1.7× as long as wide ( Fig. 46 ). Distance from posterior ocellus to inner eye margin 0.5× as the distance from posterior ocellus to occipital margin; ocelli disposed as a obtuse triangle, distance between posterior ocelli 1.8× as long as distance between anterior ocellus and posterior ocellus; ocellar region elevated. Temples 0.7× as wide as eye at bottom of ocular sinus; occipital carina distinct for entire length, strongly angled below. Outer face of mandibles flattened, with a carina running near inner margin. Scape 2.8× as long as apically wide; F1 1.8× as long as apically wide; F2–F10 progressively shorter and weakly convex dorsally; F7–F9 depressed ventrally; F11 short and strongly convex dorsally, almost globular, apex received by depression created by preceding spiraled flagellomeres ( Fig. 47 ). Mesosoma in dorsal view short, 1.3× as long as wide. Pronotal carina short but welldefined for entire, forming on humeri an acute tooth clearly visible in dorsal view. Mesoscutum as long as wide between tegulae, weakly convex anteriorly in lateral view. Scutellum in lateral view continuing curve of mesoscutum into metanotum and propodeum; anterior margin shallowly crenate. Metanotum oblique, weakly convex. Tegulae broader posteriorly than anteriorly, outer margin strongly bent inward posteriorly, posterior margin almost perpendicular to longitudinal axis of tegula; posterior lobe pointed and surpassing parategula ( Fig. 48 ). Parategulae very short and almost indistinct. Mesepisternum convex, epicnemial carina present only as an indistinct margin between two differently sculpted surfaces. Propodeum moderately convex in lateral view; posterior face narrowly and deeply depressed with an irregular basal fovea; lateral face weakly convex; lateral carina well developed from base to apex of propodeum; submarginal carina developed as pointed lamella above rectangular valvula ( Fig. 49 ). T 1 in dorsal view 4× as long as maximum width, fusiform with expanded apex; in lateral view regularly convex from base to posterior fourth, then depressed; lateral margin fused ventrally and reducing S1 to an apical sclerite; a longitudinal carina on each side of posterior third ( Fig. 50 ). T2 basally petiolate, petiole slightly longer than wide, then strongly expanded in dorsal view; apical margin in lateral view higher than apical lamella; apical lamella well developed and apically bent upward, entirely hyaline. T3 with two semicircular depression near median line, separated by an elevated ridge and margined posterolaterally by an elevation; apical lamella clearly separated from rest of surface and milky in color ( Fig. 51 ). Apical margin of T4–T5 with translucent lamella not clearly differentiated. Apical lamellae of S2–S4 similar to those of respective terga, but shorter.

Clypeus, ocular sinus, genae, lateral faces of pronotum, mesepisternum, metaepisternum and posterior depression of propodeum with dense coricate silvery pubescence. Rest of body covered by silvery setae, longer on frons, coxae, ventral face of hind femora, dorsal face of mesosoma, mesepisternum, and lateral face of T1.

Clypeus densely punctured, punctures shallow, interspaces shorter than puncture diameters. Frons, vertex and gene with large flat bottomed punctures, forming honey-comb like structure, interspaces short and shiny. Mesosoma except metaepisternum and propodeum punctured similar to frons, but punctures smaller and interspaces slightly larger. Metaepisternum dull with some sparse punctures. Dorsal and posterior faces of propodeum strongly and densely foveolate, interspaces reduced to irregular carinae. Lateral face of propodeum finely and irregularly striate. T1 with deep punctures, larger and very dense at extreme base, sparser on dorsal face, very fine and dense on lateral face; ventral face entirely smooth. T2 and S2 with dense oblique punctures, larger on sternum, interspaces about equal to puncture diameters basally, becoming shorter apically. T3 with very fine dense punctures. Following segments microreticulate.

Color. Black; following parts yellow: clypeus except basal margin, inner margin of mandibles, thin line on anterior margin of pronotum interrupted in the middle, posterior corners of T1, thin lines on T2–T4 and S2–S4 before apical lamella, apical spot on fore femora; following parts ferruginous: ventral face of antenna and whole F11, T5–T7 and S5–S7; legs except coxae brownish-black. Wings hyaline.

Female. Unknown.

Distribution. Burkina Faso: Bobo-Dioulasso.

Etymology. The specific name is in reference to the intermediate position of this species between the favillaceus and the pubescens species-groups.

Figures

FIGURES 41–48. 41–44, Synagris (Paragris) biplagiata Gusenleitner, 2005, ♂. 45–48, Zethus (Zethus) intermedius sp. nov., ♂, holotype. 41, 47, Antenna in lateral view. 42, Mandible in frontal view. 43, Propodeum in posterodorsal view. 44, Metasoma in lateral view. 45, Habitus. 46, Head in frontal view. 48, Tegula in dorsal view.

FIGURES 49–51. Zethus (Zethus) intermedius sp. nov., ♂, holotype. 49, Propodeum in posterodorsal view. 50, Metasoma in lateral view. 51, Metasoma in posterior view.