Zethus (Zethus) soikai Selis

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 : 445-447

Zethus (Zethus) soikai Selis , sp. nov.

( Figs 1 –8)

Zethus luzonensis: Giordani Soika 1960: 77 , ♂, misidentification.

Diagnosis. This species comes close to Zethus luzonensis Giordani Soika , from which it can be distinguished by: black antennae, male clypeus semicircular in frontal view and without apical teeth, female clypeus entirely black, apical flagellomere of male elongate and slightly curved with rounded apex and reaching half of F7, S2 of male with an elongate depression, T3 inflated before the apical lamella that is equally long for its entire width, S3 of female with apical median lobe, sculpture of thorax less coarse.

Material examined. HOLOTYPE, ♂, “ Surigao / Mindanao ” ( MSNVE) ; PARATYPE, ♀, “ PH – Luzon , Mt. Province, Barlig / I.2016 / Leg. local collector” ( MSVI) .

Description. MALE. Holotype. Body length 16 mm; fore wing length 12 mm.

Head in frontal view nearly circular, 1.1× as wide as high ( Fig. 3 ). Frontal ocellus diameter one third diameter of antennal socket. Distance from posterior ocelli to apical margin of vertex 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. Transverse median carina connecting antennal sockets. Clypeus in lateral view flattened and strongly bent posteriorly in ventral third; in frontal view 1.5× as wide as high ( Fig. 3 ); apical margin truncate. Scape 3× as long as its maximum width; F1 2.2× as long as its maximum width, F2–F3 longer than wide, F4–F8 wider than long, F11 elongate and slightly arched, finger-shaped, apically rounded, 2.8× as long as its basal width ( Fig. 4 ).

Mesosoma in dorsal view 1.57× as long as wide. Pronotal carina weakly raised, extremely 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 corners with 2–3 short longitudinal carinae on each side, posterior margin with short median furrow. Metanotum slightly sloping down posteriorly, 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 ( Fig. 5 ).

Metasomal segment 1 petiolate, long and slender, T1 4× as long as wide, in dorsal view gradually widening to one-sixth of tergum from base, then nearly parallel-sided apically, with maximum width 3.4× its basal width, with median carina running from basal margin to one third length, then replaced by longitudinal depression to apical margin, tergum and sternum completely fused, sutures between them absent throughout segment, in lateral view abruptly swollen from near base, then almost flat to apical margin where curved down. 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. 6 ). S 2 in lateral view straight from base to near apical margin, slightly convex apically ( Fig. 6 ), in ventral view with central depression from base to apex, two apical lateral calluses bordering depression ( Fig. 7 ). T2 with well developed and raised apical lamella, S2 with well developed but not raised apical lamella, T3 with thick apical lamella, not raised, slightly longer laterally than medially.

Clypeus with shallow punctures, each bearing long bristle, interspaces greater than diameter and smooth. 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 dense and deep 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 very sparse punctures anteriorly, becoming even sparser posteriorly, interspaces several times larger than diameter of points, dense and fine micropunctures in interspaces. Scutellum smooth and shiny, with few large and very shallow punctures. Metanotum punctate on anterior margin, punctures deep and dense, rest of surface shagreened. Mesepisternum smooth and shiny, with sparse and deep punctures dorsally, finer 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 sparser apically; punctures on T2 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–T7 smaller and sparser; S2 with punctures smaller than T2.

Head and dorsal side of mesosoma with dense golden-reddish pubescence and some sparser longer setae of same color; rest of mesosoma with long and dense silver setae; metasoma covered with dense and shorter setae, longer on apical margins of S3–S7.

Aedeagus as fig. 12 in Giordani Soika (1960).

Color. Black; following parts yellow: vertical face of clypeus except margins, line on inner margin of mandible, scape ventrally, spot at apex of fore femur; following parts ferruginous: tegula, apex of femur, apical half of fore tibia, fore tarsus. Wings strongly fuscous, with golden reflections in basal half and purplish reflections in apical half.

FEMALE. Like male, but differing as follows: clypeus simple, not bent apically, slightly wider than long, weakly tridentate apically, with dense small punctures; S2 not depressed medially; apical margin of S3 with densely punctate median lobe; clypeus, antennae and legs entirely black, spots above antennal insertions, anterior and posterior margin of pronotum and parategulae ferruginous.

Distribution. The Philippines: Luzon, Mindanao.

Etymology. This species is dedicated to the late Antonio Giordani Soika, in whose collection the holotype of this new species was found.

Notes. The holotype of this new species was wrongly described by Giordani Soika (1960) as the male of Zethus luzonensis Giordani Soika, 1941 , referring to and labeling the specimen as “ allotype ”. Giordani Soika probably did not compare this specimen with the other male present in his collection, as they appear clearly different. The possibility to examine the specimens in Giordani Soika’s collection and new specimens recently collected in the Philippines allowed to find a female specimen similar to the described male, here described as Z. (Z.) soikai sp. nov., and males similar to the holotype of Z. (Z.) luzonensis , here described as the true male of this species.

Figures

FIGURES 1 – 7. Zethus soikai sp. nov. 1, 3 – 6. Holotype, ♂. 2. Paratype, ♀. 1, 2. Habitus. 3. Head, frontal view. 4. Antenna, lateral view. 5. Propodeum, posterodorsal view. 6. T 2 and S 2, lateral view. 7. S 2, ventral view.