Back to Nature (Published on TBNWeekly.com - April 26, 2007)
Yellowjackets Spring brings about many beautiful things in life,
but it is also that time of year when my e-mail box is jam-packed with requests for
information concerning stinging wasps. And although entomology isnt my
academic area, like most of you, Ive certainly had enough experience with
these little critters, in fact Im extremely allergic to wasp and bee
The University of Florida Department of Entomology and Nematology paper on
yellowjackets states there are only two of the sixteen North American species of
Vespula (true wasps) known from Florida.
These are the two yellowjackets: eastern yellowjacket, V. maculifrons, and
the southern yellowjacket, V. squamosa.
One species of Dolichovespula is also present: the baldfaced hornet, D. maculata
(Linnaeus). The baldfaced hornet is actually a yellowjacket. It receives its common
name of baldfaced from its largely black color but mostly white face, and that of
hornet because of its large size and aerial nest. In general, the term
hornet is used for species that nest above ground and the term
yellowjacket for those that make subterranean nests. All species are
social, living in colonies of hundreds to thousands of individuals.
Commonly asked questions are: Why are there so many wasps this year?
and Why do they seem so aggressive? For answers to these questions, I
made a trip to the Pinellas County Extension Service, University of Florida,
Institute of Food and Agriculture Sciences, Department of Entomology and
Why are there so many wasps this year?
Most of the complaints Ive received concerned the yellowjacket, Vespula
Since the past couple of winters have been very mild in our area and most of the
southern USA, we have experienced an abnormal abundance of yellowjackets and other
insects. The yellowjackets nest in colonies, in large, football-shaped nests that
most often are located in and on the ground. They dont dig these nests, but
are opportunists taking advantage of old burrows, for example previously excavated
by rodents, armadillos and rabbits. I was told that nests have been discovered in
Florida as large as an old washtub! This is unusual, however, because normally the
winter cold kills off the majority of the residents. When spring arrives, the
queens emerge and the nest building begins again.
Why do they seem so aggressive?
This insect is very aggressive when defending itself or its nest.
Theyre social insects and their colonies develop in a similar way.
Adult females make up two castes: queen or fertile females which lay eggs; workers
or sterile females which feed larva and may lay eggs without mating if the queen
dies during the season. In the fall, queens and males leave the nest and mate. The
male dies and the surviving queens (during normal winters) hibernate in cracks of
rocks, under bark of trees, in buildings, or in the ground. In the spring the queen
comes out of hibernation and builds a nest with a few shallow cells. An egg is laid
in each cell and these hatch into worker larvae in two or three days. The queen
feeds these larvae which develop in 12 to 18 days and spin cocoon caps over the
cells and change into pupae. After the first brood emerges the queen resumes egg
laying. The workers take charge of the nest, enlarging it and caring for the new
Stinging or venomous insects and related pests
The problem with this arrangement in Florida is that the queen and workers for
over the last couple of years didnt hibernate or die, so we are experiencing
the results of this continuing building and growing of these nests which the male
wasps feel necessary to defend at all costs.
One suggestion to help curb this situation was very timely during this season in
Florida; pick up the fallen fruit from our yards. Wasps are attracted to sweet
nectar, ripened fruits, sweet drinks and generally all those wonderful things we
love at an outdoor picnic. Covering these items may help when outdoors.
As most of us know, pesticides are best applied at night time when the insects are
less likely to attack, but protective clothing should always be worn. When there is
any concern of an adverse reaction to a sting, youd obviously be better
having this job handled by a professional.
For below ground nests, (such as the yellowjacket) locate nest and mark area
so it is easy to find after dark. Use a flashlight covered with a red cellophane
paper so wasps stay in their nest. At night, puff dusts into nest entrance and
immediately throw a shovelful of moist soil over entrance. Be careful not to step
In spite of the bad side of yellowjackets, these insects are actually
beneficial because they attack and destroy many harmful insects found around
the home and gardens, such as: house flies, blow flies and various
caterpillars. This is little comfort to you when youre trying your best
to enjoy the best season in Florida, with company, at an outdoor party, while being
attacked by aggressive yellowjackets
the price we pay for such beautiful
weather. This is why it is so important to locate those nests before
your celebration and eradicate them.
I hope this has briefly answered a few of your questions. For more detailed
information and expert advice visit your local extension office for pamphlets and
printed documents. You will also discover a wealth of other information at your
fingertips; gardening tips, putting up the fruits of your labor for next winter and
so on. The extension office personnel are quite knowledgeable and very willing to
help you with a variety of topics. Or visit The University of Florida Department of
Entomology and Nematology Web site: creatures.ifas.ufl.edu/urban/occas/hornet_yellowjacket.
Karen can be reached at MyMuddyPawsStudio@gmail.com.