Identification Atlas of the Vespidae (Hymenoptera, Aculeata) of the northeastern Nearctic region The Vespidae of the northeastern Nearctic region are reviewed to include 92 established and four adventitious species. Six undescribed species (two each in Ancistrocerus, Euodynerus and Polistes) are recognised for the first time. Three former subspecies, Euodynerus blakeanus Cameron (subspecies of E. foraminatus de Saussure), Ancistrocerus albophaleratus de Saussure (subspecies of A. catskill de Saussure) and A. albolacteus Bequaert (subspecies of A. adiabatus de Saussure) are re-instated as or elevated to good species. Parancistrocerus vogti (Krombein) is synonymized with P. fulvipes (de Saussure). A brief introduction to the morphology, biology and distribution of Vespidae is given. Keys to subfamilies, genera and species are provided, and illustrated with 60 photographic plates (437 images) showing most diagnostic characters. All species are illustrated on 287 separate plates by means of (i) a set of standard photographs of pinned specimens (habitus lateral and dorsal, head of male and female; 537 images), and, where available, (ii) photographs of live specimens in the field (99 images). The variation (especially colour) of most species is described in detail and supplemented with brief information on distribution and biology. Twenty-two species (including five adventitious species) are recorded for the first time from Canada and numerous new state records for the U.S. are given. Euodynerus blakeanus, a taxon previously known only from Texas, is recorded for the first time from the northeastern Nearctic (New Jersey, Maryland, West Virginia) and several midwestern and southeastern states (Kansas, Missouri, North Carolina). The occurrence of E. pratensis in the northeast (recorded from Ontario) is considered doubtful. New data on the nest sites of ten Eumeninae species is provided (Ancistrocerus albophaleratus, A. catskill, A. unifasciatus, Eumenes verticalis, Euodynerus auranus, E. planitarsis, Parancistrocerus leionotus, Parazumia symmorpha, Stenodynerus anormis, S. kennicottianus). Morphological and other scientific terms are explained in an appendix.
