Hornets are large eusocial wasps in the genus Vespa. There are 22 described species native to Europe and/or Asia. Several species have become established in other regions as well, such as Vespa crabro and V. orientalis, which have been introduced into North and Central America and even Madagascar.
The keys and information provided here focus on females, that is, queens and workers. Males can be distinguished by having seven metasomal segments, no sting, and 13 antennomeres. In addition, male antennae are longer and are never held coiled or strongly curved as they are in females. Queens are generally larger-bodied than workers. Workers can be variable in body length, with smaller individuals found later in the season.
Diagnostic features focus on proportions of various body parts and coloration of the head, thorax, and banding patterns on the metasoma. Structural features used to distinguish species include development of the gena, relative positions of the ocelli to the eye margins, clypeal shape and punctation, and thoracic punctation, particularly of the scutum and pronotum.
More information on hornet morphology can be found in Smith-Pardo et al. (2020) which provides a comprehensive illustrated key to the 22 species of Vespa.
Authors: L.S. Kimsey, J.M. Carpenter, E. Jochim, A.H. Smith-Pardo, A.J. Redford
Content last updated October 2023
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