Summer Stingers: Yellowjackets pack a painful punch
Just when we thought the pest season might be slowing down a bit, along come the yellowjackets. They aren’t the normal-sized wasps we usually see; they are Jurassic Park candidates this year. These aggressive nest defenders aren’t frightened one bit by humans.
In fact, swatting at one merely pisses it off. Anyone ever stung by a yellowjacket knows a sting hurts, burns, itches and seems to last a long time. Even worse, one wasp can sting repeatedly. It’s quite an unwelcome and painful surprise to drink from a soda can with a yellowjacket in it. Just a few ruin a good picnic or barbeque in a hurry. For people who are allergic, a sting can be life threatening.
The term “yellowjacket” refers to a number of different species of wasps. They commonly build paper nests in rodent burrows, but sometimes nest in other protected cavities, such as voids in walls and ceilings of houses.
Some build nests in trees. If a rodent hole isn’t spacious enough, yellowjackets will increase the size by moistening the soil and digging. Similar behavior inside a house sometimes leads to a wet patch that develops into a hole in a wall or ceiling. Colonies, which are begun each spring by a single reproductive female, can reach populations of between 1,500 and 15,000 individuals, depending on the species (UC Davis IPM).
Although yellowjackets are beneficial predators of other insects, their aggressive behavior makes them unwelcome companions near people. Ideally, avoid their nesting places. Sometimes this is easier said than done. My husband was stung repeatedly after disturbing a ground nest while mowing weeds. “Keep foods, including pet food and drinks, covered or inside the house, and keep garbage in tightly sealed garbage cans. Once wasps discover food, they will continue to hunt around that location long after the source has been removed (UC Davis IPM).”
Lure traps that attract yellowjackets into an unescapable container using a chemical are available wherever pest control products are sold. They usually work on small populations. Even though insecticides are sold to control wasps, the wasps get very upset when their nest is sprayed, and will often attack the applicator. When spraying wasp nests, be sure to wear protective clothing that covers you completely, including a veil over your face and thick gloves. It is easiest and safest to call a professional.
Go here for more information from the University of California, Davis, Integrated Pest Management site.
— JoAnne Skelly is Associate Professor & Extension Educator, Emerita at University of Nevada Cooperative Extension skellyj@unce.unr.edu