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About hornets

True hornets are eusocial wasps that belong to the genus Vespa, and they are all native to Eurasia. The European species, Vespa crabro, has been established in the southeastern U.S. for more than a century. Vespa soror was accidentally introduced to southern California but failed to establish, and Vespa mandarinia was found in northwestern Washington State in 2020. The most recent introduction was a specimen of Vespa velutina found in Georgia in 2023. In temperate regions, Vespa colonies are annual, and new colonies are established by new queens every spring. Depending on the climate, colonies can become as large as several hundred individuals.

Diagnostic features of the genus Vespa include:

  • Brightly colored; black with yellow, orange, and/or red markings
  • Range from 3–5 cm (1–2 inches) in length
  • Head large with genal area behind the eye at least as wide as the eye in side view
  • Posterior ocellusocellus:
    single facet light reception organs; on the top of the adult head
     is much closer to nearest eye margin than to posterior margin of head in dorsaldorsal:
    the top surface of a structure
     view
  • Pronotal posterior margin strongly U-shaped, wrapping around the scutumscutum:
    the largest segment on top of the thorax located between the wings and behind the head
    , reaching tegulae in dorsaldorsal:
    the top surface of a structure
     view
  • First metasomal segment twice or more as broad as long dorsally, broadly attached to the second metasomal segment
  • Pronotal and pretegular carinae present
About hornets