Zethus malayanus Gusenleitner, 2010

Nguyen, Lien Thi Phuong & Xu, Zai-Fu, 2017, First record of the genus Zethus Fabricius, 1804 (Hymenoptera: Vespidae, Eumeninae) from China with description of a new species, Zootaxa 4272 (4), pp. 596-600 : 596-598

Zethus malayanus Gusenleitner, 2010 ( Figs 1–5 )

Zethus malayanus Gusenleitner, 2010: 695 , 704, figs 15–19, ♀.

Material examined. CHINA, Guangdong: 1 ♂, Guanyinshan Provincal Nature Reserve , 15–16.VI.2007, Zaifu Xu, No 201301318 ; 1 ♀, Liuxihe National Forest Park, Guangzhou , 1–4.VI.2007, Zaifu Xu, No PT 201302017.

Description. Male (hitherto unknown) [female characters in square brackets]. Body length 11.5 mm [12.5 mm]; fore wing length 10.5 mm [11.0 mm].

Head in frontal view much wider than high, 1.5 × [about 1.4 × ( Fig. 1 )] as wide as high ( Fig. 3 ). Vertex not [slightly] produced behind eye. Eye much more strongly swollen laterally than in female. Gena narrow [more or less wide], in lateral view slightly less than 0.4 × [about 0.6 ×] as wide as eye. Inner eye margins 1.2 × [about 1.1 ×] further apart from each other at vertex than at clypeus. Clypeus in frontal view ( Fig. 3 ) wider than high, 1.1 × [about 1.2 ×] as wide as high, apical margin truncated, without depression [with depression near apical margin]. Antenna ( Fig. 4 ) with terminal flagellomere hooked, slightly curved and sharply point at apical tip [bullet shaped], flagellomeres 3–9 with strong bristles [without bristle].

Mesoscutum with notauli developed (presenting from posterior margin to lateral margin of mesoscutum), in lateral view weakly convex, 0.9 × as long as wide between tegulae. Disc of scutellum flat, in profile at same level as mesoscutum. Metanotum weakly convex. Scutellum slightly convex, slightly depressed in middle, in lateral view at same level as mesoscutum, strongly depressed along anterior margin with 9–10 short longitudinal carinae. Metanotum sloping down posteriorly. Propodeum short, excavated medially, basal fovea about one third of length of median carina from fovea to apical margin ( Fig. 5 ), submarginal carina produced into pointed lamella.

Metasoma except terminal two segments as in female ( Fig. 2 ). Metasomal segment 2 petiolate at base, T2 and S2 with well developed and raised apical lamella, T3 with thick apical lamella, not raised. Metasomal sternum 7 normal, without tubercle.

Body surface sculpture as in female, except for shorter and sparser setae on clypeus. Mandible with scattered deep punctures. Frons and vertex up to level of posterior ocelli with coarse and deep punctures. Vertex behind posterior ocelli with shallower punctures, gena with sparser punctures and spaces between punctures smooth. Pronotum with dense deep flat-bottomed punctures, spaces between punctures slightly raised. Mesoscutum with punctures similar to those on pronotum, spaces between punctures not raised, smooth. Scutellum with several sparse shallow and large punctures. Metanotum with coarse dense and deep punctures, spaces between punctures raised to form reticulation. Mesepisternum dorsally with dense, deep and large punctures, sparser ventrally, barely punctured anteroventrally. Metapleuron with strong and short striae. Propodeum with sparse shallow punctures and striae dorsally, smooth area in between them, strong and large punctures posteriorly, rugose area laterally. T1 with dense and coarse punctures; punctures on T2 much finer and smaller, area between punctures smooth, about 2–3 × larger than puncture diameter, punctures near base of T2 denser and larger than those in other part of tergum; T3 with dense and deep punctures near apical margin, smaller ones on rest; T4–T7 with sparse sallow and small punctures at apical margin, smaller ones on rest of terga, punctures on center of S2 deeper and denser than those on T2, punctures near lateral margin denser and smaller than those on disc.

Color. Black. Clypeus yellow except all margins black. Mandible with large yellow spot. Propodeal valvulae dark brown. Tergula black with dark brown spot at center. Wings slightly infuscate, veins dark brown.

Distribution. China (Guangdong) (new record), Malaysia, Vietnam ( Gusenleitner 2010).

Figures

FIGURES 1 – 5. Zethus malayanus Gusenleitner. 1 – 2: ♀. 1. Head, frontal view. 2. Metasomal segments 1 – 2, dorsal view. 3 – 5: ♂. 3. Head, frontal view. 4. Left antenna. 5. Propodeum, dorsal view. Scale bars = 1 mm.