Zethus rugosiceps, Fox, 1899

Lopes, Rogério Botion & Hermes, Marcel Gustavo, 2025, The Neotropical Zethus biglumis species-group (Hymenoptera, Vespidae, Zethinae): description of three new species, with notes on the evolution of the group, Zootaxa 5701 (2), pp. 122-130 : 123

publication ID	https://doi.org/10.11646/zootaxa.5701.2.2
publication LSID	lsid:zoobank.org:pub:7002DD72-408B-489B-870C-505BF57B9093
DOI	https://doi.org/10.5281/zenodo.17428558
persistent identifier	https://treatment.plazi.org/id/03CE87B1-FFEC-FFA7-A4D2-FB285286F85C
treatment provided by	Plazi
scientific name	Zethus rugosiceps
status

Treatment

Identification key to species closely related to Z. rugosiceps

(run this key if reaching couplet 9 of Z. biglumis group in Bohart & Stange 1965: 183)

1. Tegula abnormally bowed out, wider posteriorly ( Fig. 7 View FIGURES 7–11 )................................. Z. willinki Bohart & Stange

- Tegula at most of same width posteriorly ( Figs 8–11 View FIGURES 7–11 )......................................................... 2

2. Ocular sinus entirely punctured............................................................. Z. proximus Fox

- Ocular sinus with an evident smooth shiny spot ( Figs 2, 4, 6 View FIGURES 1–6 )................................................... 3

3. Humeral angle blunt, barely projected ( Fig. 8 View FIGURES 7–11 ); clypeal apex strongly biconcave in frontal view with evident well marked teeth ( Fig. 12 View FIGURES 12–19 ).......................................................................... Z. nolli Lopes , sp. nov.

- Humeral angle acute, projected as an evident spine ( Figs 9–11 View FIGURES 7–11 ); clypeal apex in frontal view at most nearly straight with inconspicuous lateral teeth ( Figs 13–15 View FIGURES 12–19 )................................................................... 4

4. Pronotal carina almost straight all across in dorsal view, just briefly curved forward at the very humeral angle, which in turn barely points obliquely forward ( Fig. 9 View FIGURES 7–11 ); tegula straight along the middle of its outer margin ( Fig. 9 View FIGURES 7–11 ); mandible with subapical deflected tooth ( Figs 12, 13, 16 View FIGURES 12–19 )............................................................ Z. rugosiceps Fox

- Pronotal carina curving forward from its middle to the humeral angle, so this latter projects strongly forward obliquely ( Figs 10, 11 View FIGURES 7–11 ); tegula curved along the middle of its outer margin ( Figs 10, 11 View FIGURES 7–11 ); mandible without subapical deflected tooth ( Fig. 17 View FIGURES 12–19 ) ................................................................................................... 5

5. Clypeal apex straight ( Fig. 14 View FIGURES 12–19 ); T 1 more slender (maximum width of expansion 0,45x its own length from end of stem to its hind margin), with greatest width before mid-length of the expansion and larger coarser punctation ( Fig. 18 View FIGURES 12–19 ); tegula wider and more evenly curved on outer margin ( Fig. 10 View FIGURES 7–11 ); second metassomal segment shorter, with summit of T 2 and bottom of S2 evenly convex, not parallel to each other ( Fig. 1 View FIGURES 1–6 )............................................ Z. acromion Lopes , sp. nov.

- Clypeal apex nearly straight, with indication of biconcavity, especially due to the presence of a median blunt tooth (can be obscured by pilosity) ( Fig. 15 View FIGURES 12–19 ); T 1 more robust (maximum width of expansion 0.53x its own length from its end of stem to its hind margin), with greatest width nearly in the middle of the expansion, punctures smaller and lighter ( Fig. 19 View FIGURES 12–19 ); tegula narrower, with accentuated curvature on posterior portion ( Fig. 11 View FIGURES 7–11 ); second metasomal segment elongate, with summit of T 2 and bottom of S2, in profile, parallel to each other for a length nearly as long as the expansion of each sclerite ( Fig. 3 View FIGURES 1–6 )......................................................................... Z. coracoides Lopes & Hermes , sp. nov.