Zethus mexicanus group sensu Bohart and Stange (1965)

Included species: Z. brasiliensis de Saussure, Z. magnus de Saussure, Z. mexicanus (Linnaeus) and Z. waldoi Zavattari.

Diagnosis. Large and robust; last antennomere of males rounded; the male antenna rolled apically; interantennal carina present in males; female clypeus macro-punctate interleaved by micro-striae; occiput strongly concave; notaulices absent; tegula extended posteriorly; middle tibia with one developed apical spur; lateral propodeal carina incomplete; propodeum without dorsal aperture; mesosoma and metasoma without yellow/white markings; T1 and T2 micro-punctuated with sparse macro-punctures; stem of T2 shorter than stem of T1; T2 with abrupt expansion in dorsal view; absence of lamella in terga except in T2; gradulus absent on T3 and S3; ligulate processes in S5 (usually) and S6 (always) in males; volselar body wide; cuspis larger than digitus with thick pilosity.