Pest profile

German Yellowjacket

Vespula germanica · Hymenoptera: Vespidae[3]

The German yellowjacket is an invasive wasp from Eurasia that has spread across the northern US, displaces native yellowjackets and often nests in buildings.[1]

German yellowjacket on small flowers, showing black spots along the sides of its yellow abdomen
German yellowjacket on small flowers, showing black spots along the sides of its yellow abdomen. (c) Gianni Del Bufalo bygdb, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Workers are about 1/2 inch long and queens about 3/4 inch, black and yellow.[1]
  • The abdomen usually has a small spade-shaped black mark on the first segment and black spots down both sides from the second to fifth segments.[1]
  • Nests are horizontal combs inside a gray to brown paper envelope, usually in attics, wall voids and other open spaces, sometimes underground.[1]

Look-alikes

Look-alikeHow to tell them apart
Eastern yellowjacketEastern yellowjackets have a wide, anchor-shaped black mark on the first segment and usually nest in the ground.[2]

Where it lives

First detected in New York in 1891 and common across the Northeast by the 1970s, it now spans the northern US and southern Canada; south of Washington, D.C., it's limited to higher Appalachian elevations.[1]

US map: public records from 31 states since 1990 (GBIF).

Biology and life cycle

An overwintered queen starts each nest alone in spring; by fall, nests usually hold 1,000 to 3,000 workers.[1]

New queens and males leave to mate in fall, the males die, and new queens hibernate in dry, protected places while the old nest dies off.[1]

Nests in warm spots, including heated buildings, occasionally survive winter and keep growing, though large perennial nests are uncommon in North America.[1]

Damage and signs

  • They prey on insects and scavenge carcasses, trash, fallen fruit and sugary drinks, so they often clash with people at trash cans and picnics.[1]
  • In western New York they make up over 90 percent of yellowjackets caught in urban and suburban areas.[1]

Health risk

They sting when disturbed; people who are allergic or can't treat a nest safely should call a professional.[1]

Control

Prevention

The simplest control is to wait for the first hard frost or two, which kills these annual nests.[1]

Keep them out

To keep overwintering queens out, seal cracks in siding and around windows and pipes that lead into wall voids.[1]

Traps and physical control

Never cover or close the outside entrance of a nest in a wall void; trapped wasps may chew into living spaces.[1]

Pesticides

Insecticidal dust at the entrance works best for hidden nests; for exposed nests, aerosol wasp sprays must soak through the paper envelope.[1]

Common questions

Why are yellowjackets coming out of my wall?
German yellowjackets often nest in wall voids; don't block the entrance, or they may chew into the house.[1]
Will a yellowjacket nest die on its own?
Yes. German yellowjacket nests are annual, and the first hard frost or two kills them.[1]

Sources

  1. Penn State Extension, “German Yellowjackets.” extension.psu.edu/german-yellowjackets (accessed 2026-10-06)
  2. Penn State Extension, “Eastern Yellowjacket.” extension.psu.edu/eastern-yellowjacket (accessed 2026-10-06)
  3. iNaturalist, “Vespula germanica taxon page (order and family).” www.inaturalist.org/taxa/126155 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.