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Home >> Departments/Offices >> Cooperative Extension >> Pest of the Month >> August


Yellow Jackets and Hornets

With a little care and caution, yellow jackets and hornets can be easily and safely eliminated.

All wasps will defend their nests, but the yellow jackets and hornets are the most aggressive. Like all wasps, yellow jackets prey on a variety of insects and other arthropods. They will also eat foods that people eat, especially sweets and meats, which make them a frequent unwanted picnic guests. The yellow jacket and hornet colony will remain active for only one summer, after which the workers die and the queen survives the winter in leaf litter under a tree, only to start a new colony next spring. The nest is not reused. Yellow jackets and hornets feed on insects, so they can be considered beneficial. If the nest is located somewhere no one will accidentally bother it, leave the nest alone.

Yellow jackets usually nest in the ground, but will also nest in railroad ties, wall voids, and other above ground locations. In the spring, most yellow jackets will feed on insects. Many homeowners see "bees" flying around their hedges. These "bees" are usually yellow jackets and are there to eat insects on the foliage. Spraying the hedges with an appropriate insecticide will kill the food source of the yellow jackets, and they will soon leave the area.

In the fall, yellow jacket and hornet colonies can become quite large in size. If a nest is disturbed, they can become very aggressive and sting.

To control these stinging critters you will need to do several things. First, locate the nest. A yellow jacket nest resembles an airport. The bees take off and land in an almost straight up flight. You can see them zooming in and out as you stand from a distance. Hornet nests will be located in a tree or shrub. Their gray paper nest resembles a football or basketball in size in the summer months. The entrance hole is near the bottom of the structure. Yellow jackets may have several ground entry holes in the area - make sure you find them all. Any treatments should be done at night, because the insects are less active when it gets cooler. Your chances of being stung are greatly reduced with a nighttime assault. Wear protective clothing and try not to use any lights.

Treat the nest with an aerosol wasp and hornet spray that says it sprays up to 20 feet. Most of these products contain a pyrethrum that forms a gas that will fill the cavity, killing the yellow jackets or hornets. Check the nest the following day to see if the yellow jackets or hornets are indeed dead. You can tell this by a lack of activity around the entrance holes. It may be necessary to repeat treatment.

Pouring gasoline on a nest is NOT the way to control yellow jackets. Gasoline will sterilize the soil, get into groundwater, and evaporate into the air we breathe. Gasoline is a mixture of materials, some of which are known carcinogens. When gasoline gets on you it is readily absorbed through the skin, which can also cause a chemically burn. Gasoline has become a popular cure for yellow jackets, with some people pour gasoline into a yellow jacket nest and then light it.  One gallon of gasoline has the explosive force equal to 83 sticks of dynamite, which is not good for our environment or our health. Please never attempt to control yellow jackets with gasoline!


Honeybees are generally considered a highly beneficial insect because of their pollinating activities. In recent years gardeners have reported a significantly reduced number of honeybees visiting their gardens. Honeybees are attacked by several pests that can totally kill a colony. A beekeeper can protect his hives with some simple measures, but the native honeybees are in serious decline because of these pests. When possible, do not disturb honeybees colonies in trees. However, honeybees can become a serious problem if they find an opening to nest in an exterior wall, faulty flashing of a home, or chimney. After finding the opening, they nest in a wall void or some other interior area. The nest can survive throughout the winter if well protected. The nests are made of wax that contains many pounds of honey. If the honeybees are killed, this wax will begin to melt in the heat of the summer, causing the honey to seep out. This may cause unsightly damage and will attract other insects. It is advisable to have the complete nest removed by a beekeeper with a carpenter repairing the damaged wall.

Remember, take care when trying to control yellow jackets and hornets. They will fiercely defend their home. With proper timing and using a proper spray, you can control these irritating critters.