Revision of the West Palaearctic Latreille, with the descriptions of two species - an integrative approach using morphology and DNA barcodes (Hymenoptera, Vespidae).

The genus is revised for the West Palaearctic region based on morphology and DNA barcodes. The revision includes all known West Palaearctic species, raising the number of species in Europe to 14 and to 17 for the West Palaearctic realm. DNA barcodes were recovered from 15 species, 14 of which belong to the subgenus Polistes, and one, , to the subgenus Gyrostoma. An integrative taxonomic approach combining morphology and molecular data (DNA barcoding) was employed to resolve longstanding taxonomic problems in this group. Two species, van Achterberg & Neumeyer, (= auctt.) from W and SW Europe and Schmid-Egger, from Morocco are described as new. Erichson, 1849, and Kohl, 1898, were restored from synonymy. The following new synonyms are proposed: Zimmermann, 1930, and Pseudopolistes sulcifer var. similator Zirngiebl, 1955, under Morawitz, 1889, ; Guiglia, 1976, Polistes gallica var. ornata Weyrauch, 1938 and Gusenleitner, 1976, under Erichson, 1849, ; Polistes omissus var. ordubadensis Zirngiebl, 1955, and Arens, 2011, under du Buysson, 1911, An illustrated key includes all species and additionally three species from the subgenera Meunier, 1888 and Kirby, 1828 (including a Nearctic species recently introduced to Spain and two species occurring in Egypt, the Arabian Peninsula, and SW Asia). A phylogenetic analysis using Bayesian inference provides insights into phylogenetic relationships within the genus .