Zethus (Didymogastra) Perty, 1833

Lopes, Rogerio Botion, Carpenter, James M. & Noll, Fernando Barabosa, 2021, Cladistic analysis of Zethus Fabricius, 1804 (Hymenoptera, Vespidae): a new subgeneric classification, Journal of Hymenoptera Research 82, pp. 253-283 : 253

Zethus (Didymogastra) Perty, 1833 stat. rev.

Fig. 5

Didymogastra Perty, 1833: 144 (genus). Bohart and Stange 1965: 25 (jr. syn. of Zethus ).

Didymogastra fusca Type species: Didymogastra fusca Perty, 1833.

Zethus (Didymogastra) Dalla Torre, 1892: 9 (subgenus of Zethus ).

Description.

Interantennal carinas present. Clypeus of female short, without microstriae. Clypeal teeth absent or present. Male mandible 4-toothed. Galea length variable. Labial palpi segmentation variable. Occipital carina ventrally complete, occasionally incomplete. Vertex flat. Genal margin evenly convex. Pronotal carina lamellar with lateral portion strongly sinuous. Pre-tegular carina present, incomplete. Welts present or absent. Notaulices absent. Tegula evenly convex with outer margin raised only on posterior half. Epicnemial carina variable. Posterior carina of mesepimeron present (Fig. 5B ). Two midtibial spurs. Metanotum anteriorly margined. Lateral carina of metanotum absent. Posterior tibiae of females with one row of spines. Marginal cell apically obtuse. Dorsal aperture of propodeum present, varying from slit, to wide orifice, to two orifices. Propodeum presenting only lateral carina, resistricted to dorsal half, and without apical lamella. Propodeal orifice with rounded dorsal margin. T1 with long stem and medium expansion. Anterior margin of S1 elliptical or quadrate. Stem of T2 elongated (Fig. 5C ). Lamella of T2 well developed, sometimes reflexed. Lamellas of T3 and S3 developed and simple, without indents. S5 and 6 of males without carinas.

Observations.

Although here the very long stem of T2 is marked as a synapomorphy, it is not constant throughout the entire subgenus. Some representatives from the Zethus hilarianus group have a medium-sized stem. Part of the Zethus hilarianus group (former Z. smithii group) has been revised and phylogenetically analysed by Lopes et al. (2015).

Distribution.

Nearctic and Neotropical.

Included species-groups: Zethus fuscus and Zethus hilarianus .

Included species.

25.

Figures

Figure 5. Synapomorphic characters of Zethus (Didymogastra) indicated in Z. fuscus A habitus B mesepimeron, posterior view; arrow indicates posterior carina C second metasomal tergum; arrow indicates stem. Scale bars: 1.0 mm.