Newer research based on four nuclear genes (elongation factor-1α F2 copy, long-wavelength rhodopsin, wingless and the D2–D3 regions of 28S ribosomal RNA—2700 bp in total) suggests the higher-level relationships need to be changed, with Rhopalosomatidae as a sister group of the Vespidae and the clade Rhopalosomatidae + Vespidae as sister to all other vespoids and apoids. Additionally, superfamily Apoidea is found to be within the Vespoidea, suggesting the dismantling of the superfamily into many smaller superfamilies. Finally, families Mutillidae, Tiphiidae, and Bradynobaenidae were found to be paraphyletic.
^Brothers, D. J. 1999. Phylogeny and evolution of wasps, ants and bees (Hymenoptera, Chrysisoidea, Vespoidea, and Apoidea). Zoologica Scripta 28: 233-249.
^Pilgrim, E., von Dohlen, C., & Pitts, J. (2008). "Molecular phylogenetics of Vespoidea indicate paraphyly of the superfamily and novel relationships of its component families and subfamilies". Zoologica Scripta37 (5): 539–560. doi:10.1111/j.1463-6409.2008.00340.x.