The European hornet (Vespa crabro) is the only Vespa species to have colonized the United States. It was introduced to the eastern U.S. in the 1800s and has now spread west to the Rocky Mountains. It nests in tree hollows, wall voids, beehives, outhouses, and other above-ground sites. These photos show some of the variation within this species. Images by A. H. Smith-Pardo, USDA-APHIS-PPQ.