12-17.5 mm in length; head, thorax, and abdomen black and yellow or white; body
fairly stout; wings smoky.
In the spring the fertilized female builds a small nest and begins laying eggs.
She tends to the resulting larvae until the first brood matures into female
workers, which rear consequent larvae and extend the nest. As many as several
thousand workers may be produced in a colony in one season. Males develop from
unfertilized eggs toward the end of summer and mate. At the onset of cold
weather all the wasps, including the old queen, die except young mated females
which over winter among leaf litter or in soil.
They usually nest
underground in an old rodent burrow, beneath a landscape timber, or in a rock
wall or wall of a building, or at ground level in fallen logs and tree stumps.
In urban settings they can also be found under stairs, in fence posts, brick
walls and discarded mattresses, carpets, boxes, etc. The German yellowjackets
are often found nesting in wall voids, attics, or crawl spaces. Whether in the
ground or within a wall void, the yellowjackets nests are made of wood pulp and
saliva used to form layers of cells encased in a protective paper covering.
Adults feed on nectar and other insects, larvae are provided with pre-chewed
insects and pieces of meat. Adults can become pests around outdoor eating areas
and garbage cans because they are always scavenging for food scrapes. They also
forage for sources of sugars or other carbohydrates, such as beer, fruit, and
sweet beverages. As the new queens are produced in the colony in late summer,
they demand sugars from the workers, which the forage aggressively for sources
of sugar. They are very aggressive and will sting repeatedly at the least
16-20mm in length; body stout with black and ivory white markings on the face,
thorax, abdomen, and first antennal segment; wings smoky. These are not true
hornets but are members of the wasp family.
In the spring females construct small pendant nests with a few cells and begin
laying eggs. The first brood matures into female workers, which feed the larvae
several times a day and continue nest expansion. In the late summer males
develop out of unfertilized eggs and mate. Only young mated females survive the
winter to start the cycle again in the spring.
Gardens, parkland, meadows, and forest edges. Nests are constructed out of wood
pulp and saliva and attached to branches in the open. They consist of many
layers of cells encased in protective paper with an opening at the bottom. The
nest resembles a large inverted teardrop shaped ball, and can contain thousands
of wasps, which are extremely aggressive when disturbed.
Adults consume fruit, nectar and other insects; larvae are fed pre-chewed
INFORMATION ON BALDFACED HORNETS: The Bald faced hornet (Dolichovespula
maculata) is sometimes called the white-faced hornet, but is actually a
yellowjacket. It's easy to spot since it's our only black and white yellow
jacket. Its nest is a gray "paper" envelope with several layers of combs inside.
A mature nest can be bigger than a basketball, but pear-shaped, with the larger
end at the top and an entrance hole near the bottom. A single, over-wintering
queen begins building the nest in the spring. She lays eggs and tends the first
batch of larvae that develop into workers. These workers tend new larvae and
expand the nest throughout the summer. A mature colony can have several hundred
workers by the end of the summer. In fall, workers die and next year's queens
find over-wintering sites. Baldfaced hornets are beneficial, capturing insects
(often including other yellowjackets) to feed to their larvae. Though larger
than other yellowjackets, Baldfaced hornets are generally more docile. But they
can become aggressive and will sting when their nest is disturbed or threatened.
A Baldfaced nest is usually constructed high in a tree. In these cases the nest
is best left alone. In fact, Baldfaced hornet nests are often first noticed in
fall when leaves drop, exposing the nest. By this time the hornets are dead or
dying, and the nest will not be reused. Occasionally you will find a Baldfaced
nest built on the side of a building, in low shrubbery, or even in an attic or
shed. Nests in these sites will probably need to be eliminated.
The family Sphecidae
is made up of a large variety of solitary hunting wasps. There are about
1200 species in North America, many of which are common. They feed upon spiders
or insects such as aphids, caterpillars and cicadas. The hunting wasps feed this
prey to their young, which develop in separate nests in the ground, natural
openings or in cell constructed out of mud, like the mud daubers. The hunting
wasps do not live in colonies but often may nest together in large numbers at a
site. The solitary hunting wasps often are rather fearsome looking but rarely
sting and do so only if handled. Most of these wasps are beneficial predators of
pest species and do not require control.
Black-and-yellow Mud Dauber
25-30 mm in length; long cylindrical one segmented "waist" (pedicel) between
thorax and abdomen; body black with large yellow area on prothorax; yellow
pattern on thorax, pedicel, and 1st segment of abdomen; legs mostly
yellow; wings brown-black.
Solitary female builds a nest out of moist mud containing several parallel cell
rows. A paralyzed spider is stuffed into each cell and one egg deposited on each
spider. The female then closes the cell opening with mud. Hatching larvae slowly
consume the spiders after which they pupate inside the cell. Males are rarely
seen before midsummer and feed on nectar.
Rock faces, under rocks, overhanging roofs, attics and other structures.
Adults feed on nectar, larvae feed on provided spiders.
Unless wasps, hornets,
and yellow jackets become a threat we urge you to leave them alone. They play an
important role in the ecological balance of your backyard, neighborhood and
hornets are outside the nest during the daylight hours. Nearly the entire colony
is in the nest during the evening and nighttime hours, although some workers may
be stranded away from the nest and will not return until morning. Control
measures for hornets and yellowjackets should be attempted during the nighttime
hours when the whole colony is in or on the nest.
There are many
insecticides labeled for controlling wasps, when applied into or onto the nest.
The difficulty involves making the treatment without being stung. If
applications must be made during the day, protective equipment such as boots,
heavy coveralls, veiled headwear, and heavy gloves should be worn. This
equipment should be carefully secured in such a fashion that wasps can not slip
under cuffs or other areas of the clothing. Use plenty of masking tape wrapped
around the bottoms of pant legs and sleeves and around the collar.
An aerosol spray of one
of the many fast-acting wasp killer aerosols will quickly kill most workers
present in ariel nests.
The most difficult
problems in wasp control are generally those that involve large aerial nests of
yellowjackets or bald-faced hornets and ground or structural nests of
yellowjackets. Control of aerial nests of hornets and yellowjackets should be
attempted only while wearing a full set of protective equipment. Direct
the spray into the hole at the bottom of the nest, being
careful not to break open the side of the nest. Within a few hours, or certainly
by the next day, all the colony members should be killed by this initial
ground-nesting yellowjacket nests is best done at night for safety reasons. The
nest entrance should be located during the daytime and marked in some way for
easy and precise location in the evening. When the nest is approached at night,
it is a good idea to have the available light (spotlight or flashlight) set and
focused on the nest from a distance, off to the side. Do not hold it in your
hand, because it may attract attacking workers. It is safest to wear protective
clothing. Approach the nest slowly and carefully.
The quickest and surest way to
kill the colony is with insecticide dust. The only product registered for
wasp control in Canada is sold only to certified applicators. Dust will travel deeper into the void, in
the ground or wall, than will an aerosol wasp killer.
Mud daubers are not
aggressive about defending nests under construction. However, protective
clothing should be worn. A residual insecticide liquid or dust application to
the mud nests and the surfaces in the immediate area will provide effective
control. Then, scrape away and remove the nests, if possible.
If you are allergic or
hypersensitive to wasp or bee stings you should not attempt to control these
insects and should call a professional pest control company. Or if you do not
have the proper equipment call a professional pest control company.
(Make your own traps)
- Keeps yellow jackets away from desired area( however
will not kill out the entire colony).
- Safe. Non toxic.
- Traps place and maintained
in the early spring will help to severely reduce the yellow jacket population
in the fall.
For every female you capture in the early spring, that will eliminate a yellow
jacket nest of 500 to 5,000.
- Fruit juice or meat are lures that work well.
Placement of the trap:
1. Place traps away from all human activity.
2. Hang traps 2-4 feet above ground.
3. Yellow Jacket Traps should be baited and
placed either early morning or late evening when the yellow jackets are least
likely to be active.
4. Place traps in sunny areas when temperature is
below 80-85 degrees F.
Place traps in shaded area when temperature is above 85 degrees F.
5. If Yellow Jacket catch is low, relocate the
trap. Leave trap in an area for at least 2 days.
1. Before emptying traps, make sure all yellow
jackets are dead.
2. If live yellow jackets are present, they must
be killed before opening the trap by :
a. Pouring soapy water into the trap or
b. Placing entire trap in a freezer for 48 hours.
.3. Trap should be emptied and cleaned every 3-4
weeks. Traps must be kept clean.
Hints Only the fertilized female
yellow jacket over winter. All males die during the winter. This may be the
reason they are so aggressive in the early fall and know this is their last
When fertilized females emerge from hibernation in
early spring, she needs protein to nurse her young offspring. To start with she
is a single mom doing it all until she can raise some workers.
Outdoor events wasp control
Late-summer and fall yellowjackets are much tougher to eliminate.
Yellowjackets can be foraging from dozens of hidden nests in the area, each nest
containing thousands of workers, and they may come from nests 1,000 ft. or more
Yellowjackets change their feeding behavior in late summer. No longer the
beneficial, insect-eating predators they were in the spring and summer, they
have become freeloaders — scavenging on fruits, ice cream, beer and soft drinks.
They are aggressive and willing to sting.
Yellowjacket management at parks, festivals, football games and similar
outdoor events can be the worst job of all. The sheer numbers of yellowjackets
can be intimidating. And there is so much sweet, rich food to attract them.
IPM now prevents trouble later
You can often avoid severe yellowjacket problems in the fall by eliminating
workers and nests in late spring and summer, when yellowjacket workers are few
and their nests are still small.
Monitoring is the key. Monitoring — documented and systematic inspections at
regular intervals — is a critical part of IPM, and essential for yellowjacket
Check around a property frequently. Look for yellowjacket nests
or foraging yellowjackets. Install a few yellowjacket traps (how many will
depend on the area) and check them at each visit. Check the traps weekly or
biweekly in July and August, if possible, because this is the critical period to
head off fall problems.
If the traps begin catching yellowjackets, place enough additional traps that
they become control tools, reducing the numbers of yellowjacket workers. See if
you can track foraging workers back to their nests. Mark all the nests you find,
and come back at night to destroy the nests when most of the yellowjackets are
Do not quit when you find a yellowjacket nest; there may be many more. Keep
monitoring and keep looking.
Using traps for control
Trapping will not eliminate yellowjackets. But aggressive trapping — using lots
and lots of traps — will significantly reduce the number of fall foraging
yellowjackets and the risk of stings.
You can choose from many different commercial yellowjacket traps. Some are
disposable; most come with bait or bait enhancers. Some drown the trapped
yellowjackets; others hold them until they die from heat or until you kill them.
Not all yellowjacket species respond equally well to all traps or all baits.
Different colonies of the same species will even exhibit preference differences.
The time of the year also affects bait choice.
Experiment with different baits and traps to find the most suitable one for a
particular site. Place traps according to the manufacturer’s directions. Do not
stint; you need lots of traps to get effective population reduction.
Foraging yellowjackets are attracted to areas where food is readily available.
Their numbers and the risk of stings can be reduced, sometimes quite
significantly, simply by changing trash and food management practices.
Although yellowjackets are not the first pest to come to mind when thinking
IPM, they are actually very susceptible to the IPM approach. Fall yellowjacket
problems at outdoor events, in fact, can only be successfully managed through
IPM. Insecticides alone will have little effect. PC