Zethus (Zethus) luzonensis Giordani Soika, 1941

Selis, Marco, 2017, Revision of the Zethus luzonensis species-group (Hymenoptera: Vespidae: Eumeninae), with description of a new species, Zootaxa 4232 (3), pp. 444-450 : 447-449

Zethus (Zethus) luzonensis Giordani Soika, 1941

(Figs 9–13)

Zethus luzonensis Giordani Soika, 1941: 215 , 217 (key), ♀, “Filippine: Lamao, Luzon” (holotype, ♀, MSNVE)

Diagnosis. Similar to Zethus soikai sp. nov., but differs as follows: orange antenna, male clypeus triangular in frontal view and with two apical teeth, female clypeus with basal orange spots, apical flagellomere of male shorter and pointed apically, S2 of male not depressed, T3 not inflated preapically, S3 of female simple, sculpture of thorax coarser.

Material examined. PHILIPPINES: LUZON: Lamao, 2♀ ( MSNVE, 1♀ holotype); Dingalan , Aurora, VII.2015, 1 ♂ ( MSVI) ; MINDANAO: Zamboanga del Norte, 11 km E of Sindangan , 20.VII.1958, H.E. Milliron Collector, 1♂ ( MSNVE) ; Iloco, Pagudpud , II.2016, 1 ♀ ( MSVI) .

Notes. The male described in Giordani Soika (1960) does not belong to this species, it described above as Z. soikai sp. nov. The description and the genitalia represented in that publication should be referred to the new species. The original description of Zethus luzonensis , ♀, is quite poor, both sexes of this species are redescribed.

Description. FEMALE. Holotype. Body length 14 mm; fore wing length 11 mm.

Head in frontal view nearly circular, 1.1× as wide as high (Fig. 9). Frontal ocellus diameter one third diameter of antennal socket. Distance from posterior ocelli to apical margin of vertex 2.2× as long as distance from posterior ocelli to inner eye margin. Area between ocelli swollen, with small lobes on inner margin of posterior ocelli. Occipital carina complete, strongly thickened laterally. Clypeus in lateral view weakly convex; in frontal view 1.1× as wide as high (Fig. 9); lateral margins crenulate, apical margin very weakly emarginated, with small tubercle medially. Scape 2.7× as long as its maximum width; F1 1.6× as long as its maximum width, F2–F9 wider than long, F10 bullet-shaped, as long as basal width.

Mesosoma in dorsal view 1.5× as long as wide. Pronotal carina weakly raised, weakly produced at humeral angles, reaching ventral corner of pronotum. Mesoscutum with notauli developed from posterior margin to anterolateral margins; in lateral view weakly convex, as long as wide between tegulae. Scutellum flattened, strongly depressed along anterior margin with 7 short longitudinal carinae, with shallow median furrow. Metanotum convex, with longitudinal carina on each side. Propodeum with median part deeply concave, bordered by two lateral carinae, with distinct median carina from near base to apex, with fovea at base, submarginal carina produced into long and tooth-like lamella.

Metasomal segment 1 petiolate, long and slender, T1 3.9× as long as wide, in dorsal view gradually widening to one-sixth of tergum from base, then nearly parallel-sided apically, with maximum width 2.5× its basal width, with median carina which runs from basal margin to one third length, tergum and sternum completely fused, with only longitudinal shallow sulcus on ventral side, in lateral view abruptly swollen from near base, then weakly convex to apical margin. Metasomal segment 2 petiolate at base. T 2 in dorsal view gradually convex from base to half length, then nearly parallel sided, 1.6× as long as wide, in lateral view curved up in basal third, then flattened (Fig. 12). T2 with well developed and raised apical lamella, S2 without apical lamella, T3 with thick apical lamella, not raised, slightly longer medially.

FIGURES 8–15. 8. Zethus soikai sp. nov. 9–13. Z. luzonensis . 14, 15. Z. celebensis . 8, 9. ♀. 10–15. ♂. 8–10, 15. Head, frontal view. 11. Antenna, lateral view. 12. T2 and S2, lateral view. 13. Aedeagus, lateral view. 14. Habitus.

Clypeus with deep and dense punctures, each bearing long bristle, interspaces smaller than diameter of points. Frons densely covered with deep and large punctures, border between punctures raised to form reticulation. Vertex with shallower and sparser punctures. Gena with deep and dense punctures along eye margin. Pronotum with big and shallow punctures anteriorly on dorsal side, smaller and sparser posteriorly, interspaces smooth with sparse and fine micropunctation, lateral faces strongly striate. Mesoscutum almost entirely smooth, some shallow and sparse punctures anteriorly, becoming sparser posteriorly, interspaces several times larger than diameter of points, dense and fine micropunctures in interspaces. Scutellum smooth and shiny, with few small and shallow punctures. Metanotum smooth with some punctures on anterior half, punctures shallow and sparse, rest of surface shagreened. Mesepisternum smooth and shiny, with sparse and deep punctures dorsally, smaller and shallower punctures ventrally, pleural sulcus filled with big and deep punctures, epicnemium shagreened and opaque. Metapleuron shagreened and shiny, some shallow punctures ventrally. Propodeum with coarse micropunctation along each side of median carina, dorsal and lateral faces shagreened and with dense deep and large punctures on margins between them. T1 covered with small and deep punctures, denser basally and laterally; punctures on T2 very fine and small, area between punctures smooth and many times larger than puncture diameter; T3 with dense and deep punctures laterally, with finer and smaller punctures medially; punctures on T4–T6 smaller and sparser; S2 with punctures deeper and denser than T2.

Head and dorsal side of mesosoma with dense golden-reddish pubescence and some sparser longer setae of same color; rest of mesosoma and propodeum with long and dense silver setae; metasoma with dense and shorter setae, longer on S2 and on apex of following segments.

Color. Black; following parts ferruginous: rounded basal spots on clypeus, antenna, tegula, apex of femur, fore tibia and fore tarsus entirely. Wings strongly fuscous, with weak purplish reflections.

MALE. Like female, but differs as follows: clypeus with anterior vertical face heart-shaped (Fig. 10), ventral horizontal face short with two apical flattened teeth; apical flagellomere pointed apically, reaching half of F8 (Fig. 11), apically with short setae ventrally; anterior face of clypeus yellow. Aedeagus in fig. 13.

Distribution. The Philippines: Luzon, Mindanao ( Giordani Soika 1941, 1960).