Zethus (Zethoides) hexacirratus Lopes, 2024

Lopes, Rogério B. & Noll, Fernando B., 2024, Taxonomic notes on the Zethus olmecus de Saussure, 1875 species group (Hymenoptera, Vespidae, Eumeninae), with the description of five new species, Zootaxa 5437 (3), pp. 363-383 : 373-375

Zethus (Zethoides) hexacirratus Lopes , sp. n.

( Figs 88–91 )

Type material. Holotype, ♀, “ BRASIL, SP, Sta. Rita do Passa Quatro / Parque Pé-de-Gigante / 04.ix.2001, 605/ Mechi, M.R. col. [ RPSP]. Paratypes: 1♀, same data as holotype/ 575 [ RPSP]; 1♁, same data as holotype / 06.vi.2001, 335 [ RPSP]; 1♁, “ 21.iv.2004 / Complexo Aporé—Sucuriú, MS [Brazil, Mato Grosso do Sul] / Aoki, C. e Longo, J.M.” [ UFGD]; 1♀, “Cáceres, MT [Brazil, Mato Grosso]/ 04.xii.1984 / C. Elias leg./ POLONOROESTE” [ DZUP]; 1♁, “Baixo Guandu—E. STO. [Espírito Santo]/ BR [Brazil] 10–15.viii.1970 / C. & C.T. Elias leg. [ DZUP]. 1♀, “Brasil, Goiás, Silvânia/ FLONA de Silvânia/ 16–24.i.2021 / Dorig„o-Guimar„es, F. col.” [DZSJRP-Hymenoptera]; 1♀, “Pto. Bertoni/ Paraguay 19/ coll. Bertoni // 3183// IBNPY-INVERT 0000000008613” [ DZUP].

Diagnosis. The enlarged apical propodeal lamellae and dull, densely micropunctate mesepisternum on both sexes distinguish this species. Also, the small median clypeal tooth of females and the long, clustered pair of setae on S4–6 of males are distinctive.

Description. Female. Coloration. Black, with the following markings yellow: Mandibles; clypeus; spots above antennal socket and in ocular sinus; hypostoma; gena inferiorly with a wide band extending dorsally along eye margin; pair of large humeral spots; proepisternum; parategula; anterior and posterior tips of tegula; scrobal spot; foreleg except for dorsum of femur; apical third of outer surface of midfemur; longitudinal stripe on mid tibia; propodeum with a pair of longitudinal bands along apical portion of submedian carina; apical band of T1; narrow bands on T2 and S2. Orange: antennae ventrally. Propodeal apical lamella hyaline and valvula amber. Wings hyaline with costa and venation dark brown. Structure. Mandible 5-toothed. Clypeus with straight apex baring a small median tooth. Gena in dorsal view evenly convex. Pronotum long, humeral-tergular distance longer than inter-humeral distance. Pronotal carina higher on humeri than medially. Pronotal angles not projected. Parategula digitiform. Tegula with outer margin evenly convex, posteriorly narrow. Scutellum flat. Metanotum nearly flat. Mid-tibia with two spurs. Dorsum of propodeum leveled with metanotum and scutellum. Apical propodeal lamella triangular with wide rounded tip. T 1 in dorsal view with angulate expansion. T2 angulate in profile, with long straight posterior portion.

Sculpture. Clypeus moderately striato-punctate with dense micropunctation. Frons, vertex, pronotum, mesuscutum, scutellum and mesopleura densely micropunctate with moderate to sparse macropunctation. Posterior half of gena smooth and shiny. Mesoscutum and scutellum with occasional striato-punctation. Metanotum with dense small macropunctation on posterior face. Propodeum dorsally with few large crater-like punctures, laterally with smaller, coalescent punctures disposed in at most two rows and medially with transverse striae. Lateral and submedian propodeal carinas complete, the latter with a gradual curvature at base. T1 with moderate macropunctation and dense micropunctation. T2 with dense micropunctation obscuring moderate macropunctation. S2 similar to T2 at sides, medially with moderate to sparse macropunctures intercalated by smooth areas. T3 and S3 with dense and evident micro and macropunctation. T4–6 and S4–6 densely micropunctate. Pilosity. tomentum of dense short thin setae covering most of body, including clypeus. Posterior half of gena bare. Mid femur with ventral patch of longer setae, which are not erect. Propodeum apically with longer setae. Apical setae on S2, T3–5 and S2–5 thicker and longer. Apical sublateral setae in S4–5 even longer and erect. Apical third of T6 and entire S6 with erect setae. Measurements. fore wing length: 8.1 mm

Male. As in female, except the following. Coloration. Scape yellow except for dorsal band; pair of large spots on scutellum; apical yellow band on T3 and S3; scape and flagellum entirely orange. Structure. Mandible 4-toothed. Clypeus with concave apex forming acute small pair of teeth. F-XI subquadrate. Pronotum short, humeral-tegular distance shorter than inter-humeral distance. S6 with a pair of sublateral lumps. S7 with a shallow notch apically.

Sculpture. Macropunctation present and evident on entire head, coarser and denser. Vertex and posterior half of gena macro and micropunctate. Transverse striae on posterior face of propodeum stronger. Overall macropunctation on mesosoma and T1 denser and coarser. Pilosity. Ventral patch of midfemur longer and denser, but still not erect. Sublateral setae of S4–6 longer and clustered, rising from sublateral lumps in S6. Male genitalia ( Fig. 98 ). Gonocoxite with quadrate apex. Aedeagus with wide and rounded basal plate; apodemes with wide flattened apex; ventral lobe irregularly serrated on ventral margin; body elongate slightly dorso-ventrally; head truncate. Volsellar body falciform, regular with little to no tubercles or keels. Volsellar membrane highly pilous. Digitus with root slightly concave at base, wide and short basal lobe and wide well-developed apical lobe; both lobes with long setae, remarkably so on the apical lobe. Cuspis with three projections, a larger beak-like, followed by a quadrate and lastly a small digitiform projection; basal lobe absent; apical lobe long and narrow. Measurements. Fore wing length 6.8 mm.

Distribution. Brazil (Mato Grosso, Goiás, Mato Grosso do Sul, S„o Paulo, Espírito Santo), Paraguay.

Etymology. The name refers to the three pairs of very long clustered setae on the male metasomal sterna.

Observations. Size of other specimens vary between the sizes mentioned above (6.8mm–8.1mm). Yellow markings may vary in size on gena, pronotum, scutellum and propodeum, possibly lacking on the latter two. While most specimens are recorded from Cerrado areas of mid-western Brazil, the females from Espirito Santo, Brazil and Puerto Bertoni, Paraguay bring curiosity as they are from the Atlantic Rainforest. They present a longitudinal, elongate, lightly raised, smooth band (somewhat like a very blunt and wide carina) dorsally on the apical half of T1. While other specimens present a slight elevation in the same region, the area is similarly sculptured as the rest of the sclerite. Still, the specimen from Goiás, Brazil bears a very feeble and narrow smooth region (unnoticed at first), much narrower than the specimens from the Atlantic Forest. As it seems to be a trait with gradual discrepancy, we have decided to leave this trait as a variation, as no other characters compel us to assign these females to a different species.

Although both females and males have sublateral erect setae on the metasoma, the latter is more notorious as they originate very close to each other and are clustered. Females of the Z. olmecus group seem to share this trait of longer erect sublateral setae on S4–6, varying in density among species. As for the males, the overall pattern seems to appear as very dense and erect setae on the sterna of Z. miniatus and related species, becoming sparser and concentrated apically on Z. toltecus , Z. velezi and Z. hexacirratus , with Z. utingensis bearing the most sparse pattern with few isolated setae. Additionally, Z. toltecus presents the sublateral lumps on S6, but the setae rising originate more separately and are not clustered.

Figures

FIGURES 98. Male genitalia of Zethus hexacirratus (left) and Z. utingensis (right). Aedeagus in ventral view (above), lateral view (medium) and gonocoxite and volsellar complex in inner view (below). Dashed circle shows oblique close-up of apex of digitus. Dashed lines indicate underlaid structure. Cuspis highlighted in gray. Scales: 1.0 mm.

FIGURES 88–91. Zethus hexacirratus sp. n., female holotype (88, 89) and male paratype (90, 91). 88, 90. Habitus. 89, 91. Head, frontal view. Scales: 1.0 mm.