German Yellowjacket — Vespula Germanica
The German yellowjacket is an introduced species,
probably from Europe. It has been found in many states
since the 1970s, and has been in the West since about
1993. The worker is about 1/2-in. long and has yellow
and black stripes on its abdomen. The queen is about
This species features yellow and black stripes and very
little hair. Black spots are present on at least one
abdominal tergite. The lack of barbs on the stinger
allows them to sting repeatedly. The mouthparts are
developed to capture and crush prey, while the tongue
is used to suck fluids. German yellowjackets are scavengers
as well as predators.
Like all pestiferous yellowjackets, the German species
is a social one, with unique castes. Each nest has reproductives
(the queen and males). Sterile workers (females) gather
food, care for the queen, protect and expand the nest
and care for the young.
Colonies are annual, with inseminated queens overwintering.
During this time, they hibernate in protected places
such as woodpiles, leaf litter, within soil and in structures.
The queens emerge in the spring and build new nests.
Queens and workers chew wood fibers mixed with their
saliva to create a gray, paper-like pulp. Nests are
soccer- or football-shaped, and are located underground
or inside buildings. They each contain about 30 to 50
cells, with completely enclosed immatures.
The queen must feed her first brood alone. By mid-June,
the first brood matures into workers and takes over
all the duties of the nest. In warmer parts of the country,
the first brood matures a few months earlier.
The queen will now remain in the nest and reproduce
until her death. Workers chew up meat and feed it to
the larvae. The larvae process the meat and return a
fluid-like sugar material to the adults.
German yellowjacket nests usually contain about 1,000
to 3,000 workers, 10,000 to 15,000 brood cells, and
are between 18 to 30 inches in diameter at their peak.
However, enormous colonies of more than 50,000 cells
have been found in wall voids and attics in the fall.
In very cold area, the nests die out by themselves,
however, in the Sacramento area the yellowjackets usually
survive the winter with their nests. I have pulled nests
as large as 30,000. Normally the nests that I control
are about 1,000 to 3,000.