University of Maryland Extension

European Hornets

Back to Common Problems - Trees and Shrubs

European hornetEuropean hornet
Photo: EPA

Key Points

  • The European hornet is the only true hornet in the United States.
  • A social wasp, European hornets are large, about 3/4 to 1 3/8 inches long. They are brown, with yellow stripes on their abdomen and a light-colored face.
  • They build fragile, tan paper nests in concealed places like hollow trees, barns, outbuildings, hollow walls of houses, attics, and abandoned bee hives. Unprotected nests are covered with a brown envelope. The average nest contains between 200-400 workers.  
  • They are not aggressive but do have the potential to sting if they feel threatened.

General Information

  • Feed on a variety of insects including yellowjackets, butterflies, and bees.

  • They are night fliers and often hunt at night but are seen during the daytime hours too. Often attracted to outdoor lights in the evening.

  • Workers will also girdle twigs and branches of trees and shrubs (especially birch and lilac) to feed on sap and insects attracted to the sap. Branch dieback can occur when twig girdling is extensive.


European hornet
European hornet on damaged branch
Photo: Jim Baker, North Carolina State University, Bugwood.org


Management

  • If a nest is in an inaccessible location or it the hornets do not present a problem, leave the nest alone. All occupants will die during winter, except for new queens. They leave the nest and overwinter elsewhere. Nests are not reused next season. Home remedies such as flooding nests with a hose are not advisable and not necessarily effective. This may cause the wasps/hornets to become aggressive and sting.

  • Turn off porch lights at night if that is when you notice them.

  • If the nest is located near or inside a home or building and control is necessary contact a pest control professional. They have the proper equipment and materials to destroy a nest safely and effectively.

  • During the days following treatment, monitor the nest opening for activity but only from a safe distance. 
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