For Release September 5, 2000

Be Wary of the Yellowjackets

by Chuck Otte, Geary County Extension Agent

I think we all knew that when last winter was so mild, we would have a wealth of problems this year. The yellowjacket is a type of wasp or hornet that sort of looks like a smooth, streamlined honeybee. Yellowjackets overwinter as fertilized queens. The few that normally survive the winter go their separate ways in the spring and start their new nests. This year, because of that mild winter, we had a lot more queens that survived the winter.

Yellowjackets usually nest in the ground. Theyíll find an old mouse or rodent den or sometimes a cavity in or under a rock or move into the wall of a house. You will not see an exposed nest underneath your eaves like paper wasps will build. All you will usually see is a stream of wasps coming and going from a hole in the ground.

Early in the season, the queen has to do everything herself. She gathers all her own food. She locates a nest site and starts building a few cells. She lays eggs and gathers food for these few developing young. As the summer continues, the colony grows larger. By late summer the queen is spending all her time laying eggs. Other members of the colony are building more cells, gathering food for the young and the queen, and protecting the nest from invaders.

Early on, the queen and small colony are very tolerant of activity near their nest. You can walk by or right over the nest. You can mow, garden or play around the nest and not much will happen. But once we get into late summer and early autumn a change comes over the colony. Maybe itís the sense that the season is soon going to end. Or maybe itís just the overall size of the colony. But whatever it is, the colony becomes very sensitive to activity near it. The yellowjackets become very aggressive not only at protecting their nest but at gathering food. All of a sudden one day, you do the same thing youíve been doing all summer and you are suddenly attacked by a dozen very mad yellowjackets.

Yellowjackets, unlike honeybees, can sting many many times. They are very aggressive and will chase you a long ways. Even if you donít disturb their nest, the yellowjackets will probably find you, especially if you are outside with food or drink. Yellowjackets will find you and your food. They will hover near you trying to get to your food. They are nervous to begin with, and if you start swatting at them, they will become more aggressive and a sting can easily result. Yellowjackets have a sweet tooth and will quickly go after sodas or other sweetened beverages. They are also attracted to meat protein sources.

Avoidance and tolerance is the best approach. If they are around your food, move slowly and quietly, trying to get your food away from where they are. If you find a yellowjacket nest near your home, you can try to destroy it but proceed with caution. Go after the nest at night using a liquid or dust insecticide and pour it into the nest hole. Wait a few days then investigate to see if there is still activity and retreat as needed. If you are allergic to wasp or bee stings, DO NOT attempt to deal with a nest yourself.

Once we start getting some freezing weather, in another month or two, then this problem will be over. Until then, be alert and proceed with caution. For more information and suggestions on dealing with yellowjacket problems, contact the Geary County Extension Office at 238-4161 or at 119 East 9th Street in Junction City.


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