Yellow Jacket Activity

Yellow jackets can be a nuisance because their scavenging behavior often brings them into contact with humans. In fact, the vast majority of insect stings in the United States are caused by yellow jackets. Awareness of the activity of yellow jackets over the course of the year can help you develop a plan for dealing with them and avoiding their painful stings.



Winter: Except for the German yellow jacket species, yellow jackets wasps are not a problem in the winter. Workers, males, and the original queen die off with the cold and the wasps that will become next year’s queens hibernate. Sometimes these queens will hibernate inside a house, which may cause a problem when they emerge to start a new nest.



Spring: The new yellow jacket queens start their own nests as the weather gets warmer. Queens lay the eggs that will develop into a new yellow jacket colony, and have a great appetite for protein to feed the new colony. Trapping these wasps in the spring is therefore an effective way to cut down on a yellow jacket problem later in the summer – trapping a queen during the spring prevents her from laying the eggs that will become aggressive adult yellow jackets as the summer goes on. Nests are much easier to destroy in the spring, when they are small and contain fewer yellow jackets. Sometimes young yellow jacket colonies are destroyed by late spring freezes.



Summer: The yellow jacket nest continues to expand. The queens lay the eggs that will develop into next year’s queens and into the "kings" that will be their mating partners. The worker population increases, and these yellow jackets workers become significantly more aggressive in their search for food. Yellow jackets are not attracted to flowers, but are especially attracted to sugar and protein, available in abundance from our food and beverages. Be especially careful to clean up after picnics, keep pet food indoors, and keep garbage areas as contained as possible.



Late Summer and Fall: Yellow jacket hives reach peak size and the yellow jacket workers are at their most aggressive state. The new queens and the kings will mate, and the queens will seek out shelter for their winter hibernation. Keep yellow jackets from setting up for the winter in your home by doing preventive maintenance such as sealing cracks or refitting windows before the fall arrives.