Black and yellow yellowjacket wasps that resemble bees, scavenging on dead honey bees at colony entrance; sometimes capturing live bees; entering colony (when opened) to steal honey. Weak colonies most vulnerable to attack.
Yellowjacket is the common name in North America for predatory social wasps of the genera Vespula and Dolichovespula. Yellowjackets are primarily scavengers. They feed on dead bee bodies discarded in front of colonies. In weaker colonies or opened colonies, they may enter colony to feed on honey or ripening nectar.
They are sometimes credited with killing a colony, but they are only serious when attacking a colony too weak to defend itself.
Yellowjacket control is difficult. Eliminating yellowjacket ground nests in the immediate vicinity of the hive may provide some relief. Beekeepers in the Pacific Northwest (Oregon, Washington, and Idaho) use yellowjacket traps season-long in an attempt to reduce wasp numbers. This might result in impressive catches, but trapping may not significantly reduce their predation, even at densities of one trap per colony. Adding robber screens or reducing entrance size permits more effective entrance guarding by bees.
Yellowjackets appear similar to many bees and other wasps and insects. See the North American Hornet Screening Tool for more information on similar-looking bees, wasps, and other insects.
Yellowjacket scavenging resembles the robbing behavior of worker bees; flies feeding on adult remains or honey may be confused for wasps.
Entomology Today. 2019. Yellowjackets: A Look at Opportunistic Raiders of Honey Bee Hives. Entomology Today. Accessed 2023. https://entomologytoday.org/2019/03/28/yellowjackets-opportunistic-raiders-honey-bee-hives/
Breece C, Wyns D, and Sagili R. 2018. Protecting Honey Bees from Yellowjacket Wasps. Oregon State University Extension EM 9211. https://catalog.extension.oregonstate.edu/sites/catalog/files/project/pdf/em9211.pdf
Anson Extension. 2021. Yellowjacket Wasps are Not Honey Bees. Anson Co NC Extension. Bee Culture. Accessed 2023. https://www.beeculture.com/yellowjacket-wasps-are-not-honey-bees/
