The European Paper Wasp
Polistes dominulus
Photos and Narrative by Bob
Hammon, CSU Extension, Tri River Area, Grand Junction office.
The European paper wasp is native to Europe and parts of Asia and Africa and
was first recorded in North America in 1981. It is a highly successful colonizer
and it expanded its range in the eastern and midwestern USA in the next 20 years.
It appeared in California and Washington in 2001 or 2002, and in Colorado in
2003. The initial Colorado records were from Fort Collins, but it had become
well established in the Grand Junction area by June 2003.
Paper wasps are very similar to yellow jackets and the Western Colorado native
species of paper wasp, Polistes fuscatus aurifer. P. dominulus
is smaller than P. fuscatus aurifer, with a narrower abdomen. The yellow
banding on the abdomen is similar in both species. The "waist" is
very thin in all paper wasps. When flying, the hind legs trail below the body
in an extended manner. This characteristic is useful in distinguishing between
paper wasps and yellow jackets.
The nests of paper wasps are distinctive. They are formed in an upside-down umbrella
fashion, and the open cells can be seen from below. Nests are constructed in protected
area, under eaves of structures, in hollowed out holes, or when voids can be accessed
through a small entrance. Nests have been reported from exterior lighting fixtures,
animal skulls, parking meters, bird boxes, gas grills, automobiles and many other
sites.
Paper wasps over winter as fertilized queens which begin new colonies each year.They
spend the winter in any of a variety of protected areas. Queens will occasionally
use a previous years nest to begin a new colony. The queen deposits a small elongated
egg in each cell of a nest, which hatch in a few days. She will collect caterpillars
and other insects which are masticated and fed to the developing larvae. After
the first brood of larvae mature, pupate, and emerge as adults of the worker caste,
the queen will limit her activity to laying eggs. The workers assume all of the
food collecting and nest protection duties. With summertime temperatures and a
plentiful food supply, a generation can be completed in 40 days.
The European paper wasp has already largely replaced the native species in much
of the region. Some reasons for the competitive advantage to P. dominulus
over our native paper wasps include:
- Earlier establishment of colonies in the spring, which allows it a competitive
advantage in collection of early season prey. Early nest establishment also
avoids some bird predation, and allows the production of early season workers
to hunt for prey and protect developing larvae.
- The habit of using protected nesting sites provides protection from predation.
The European paper wasp utilizes small holes and voids to make nests, which
are sites the native species does not exploit to the same extent.
- The native paper wasps prey on caterpillars, while the European paper wasp
capture a variety of insects from several orders. The varied diet of our new
invader gives it a distinct advantage over the native species.
- European paper wasps reuse nests that have been abandoned for various reasons,
while our native species do not reuse nests. European paper wasps have an
advantage in being able to establish colonies more quickly than the native
paper wasps.
European paper wasps aggressively protect their nests. They can detect movement
up to 20 feet away, but usually don't attack unless the threat is within inches.
The habit of building nests in small voids increase chances of a person being
stung. This wasp is extremely common in urban settings, which means many people
are potentially exposed to it.
Management of European paper wasps takes two forms: preventative and controlling
nests and adults. Preventative measures include limiting suitable nesting sites.
Repair holes in walls, caulk cracks in soffits and eaves, screen vents. Eliminating
early season nests will aid in controlling later season nests. Single queens are
much easier to control than nests with many workers.
Wasp and Hornet sprays in aerosol cans are a preferred method of controlling nests
with workers that are easily accessed. These shoot a spray of insecticides up
to 20 feet. Most contain pyrethroid insecticides that are safe to use and have
quick knockdown and residual activity against wasps. Treatments should be made
at night when all workers and the queens are on the nest. Remove and destroy the
nest after you are sure all wasps are dead. This ensures that it will not be reused.
Nests located within voids can be treated with dusts which are blown into the
entrance holes. Many pest control firms provide wasp control services.
Placed on the Internet Thursday, August 21, 2003
WebMaster Dr.
Curtis E. Swift, Area Extension Agent, Horticulture
Colorado State University Extension
2775 US Hwy 50, Grand Junction, CO. 81503
voice: 970-244-1834
fax: 970-244-1700