Cladistic analysis of the Zethus (Zethoides) Fox, 1899 (Hymenoptera, Vespidae, Eumeninae) species groups with insights on the current subgeneric classification of Zethus Fabricius, 1804

Zethus is the largest genus in Eumeninae, with over 250 species. Currently, it is divided in four subgenera: Z. (Zethus), Z. (Zethusculus), Z. (Zethoides) and Z. (Madecazethus). Z. (Zethoides), with 42 species, is subdivided in eight species groups, each considered a phylogenetic unit, that were created without any phylogenetic analysis. Eighteen species of Z. (Zethoides) corresponding to different groups were examined, altogether with terminals from distinct lineages of Zethus, Zethini and Eumenini, to perform a cladistics analysis to verify the proposed divisions. Zethus (Zethoides) and all of its species groups, except for the Z. biglumis group, were monophyletic. Zethus s.s. was paraphyletic in relation to Z. (Madecazethus), Z. (Zethoides) and Ctenochilus. Z. (Zethusculus) was also retrieved paraphyletic. Despite the subgeneric incongruences, the outgroups were too poorly represented to carry a taxonomic modification. Thus, the only alteration was the inclusion of the Z. clypearis group in the Z. biglumis group.