It’s hard to like yellowjackets. They sting, cause violent allergic reactions in some people, harass picnickers, and have a knack for causing trouble at the wrong time. They seem persistent, clever, and difficult to manage. This doesn’t mean, however, that reaching for a spray can is a good way to deal with a yellowjacket problem. Chemical-free techniques are surprisingly effective.
What Is a Yellowjacket?
Yellowjackets, sometimes known as hornets, are wasps that are black and yellow or white. Common pest species in the Northwest are the western yellowjacket, the common yellowjacket, and the German yellowjacket. A wasp that is commonly mistaken for a yellowjacket is the paper wasp. They are longer and more slender than yellowjackets and are usually unaggressive (see Bees & Wasps). Their nests are a single comb, and not surrounded by a paper envelope.1,2
All yellowjackets build paper nests that are completely surrounded by a paper envelope. Most yellowjackets nest underground. They often use burrows made by rodents or other natural openings as nest sites. The German yellowjacket likes to nest inside walls of houses. There are two kinds of yellowjackets, the aerial yellowjacket and the bald-faced hornet, that hang their nests from trees or building eaves.1
Most yellowjackets defend their nest vigorously, and being near a nest means you’re likely to get stung. Typically, the ground-dwelling yellowjackets are the most aggressive, while those that nest above ground are somewhat less touchy.1
Most yellowjackets die with the first frost in the fall. The nest is abandoned and typically not used again. Only the queens find a protected spot to spend the winter. In the spring, the queens build new nests and begin laying eggs which hatch into worker wasps. All summer the number of workers increases. By the end of summer there can be thousands of yellowjackets in a nest. This is typically when the yellowjackets are most troublesome.2
Yellowjackets are Important
Yellowjackets feed their young large numbers of insects that might otherwise damage trees or crops. They also feed their young houseflies, lots of them. What this means, according to the University of California, is that they “should be protected and encouraged to nest in areas of little human or animal activity.”1 If you find yellowjackets in a place where people and pets are unlikely to get close, it’s a good idea to just let them be.
Preventing Yellow Jacket Problems
Prevention is the best solution. If you’re expecting yellowjacket problems, there are some simple steps you can take to reduce or eliminate them.
- Don’t provide these scavengers with food or drink. If you have a meal outside, keep the food and drink covered as much as possible. If you feed your pets outside, keep the pet food covered.1
- Keep a tight lid on garbage cans. Also eliminate any standing water.1,3
- Avoid behavior that attracts yellowjackets. Avoid perfume, sweet smelling shampoos, or other scented body care products. Don’t wear bright colored clothes, particularly yellow, or floral patterns. Yellowjackets seem to be attracted by these colors.4
- Avoid taking action that angers yellowjackets. Stay away from their nests as much as possible.1 Don’t swat at yellowjackets that approach you since this can provoke them to sting. Don’t let children throw rocks or other items at nests.4
Traps can be an effective, pesticide-free technique for managing yellowjackets. Trapping experts have some tips for making this technique work well:
Homemade traps are usually made from a five gallon bucket. Fill the bucket with soapy water and hang a protein bait a couple of inches above the water. You can put a wide mesh screen over the bucket and bait so that pets or other animals don’t eat the bait. The yellowjackets grab a piece of the bait too heavy to fly with, then fall down, get trapped in the water, and drown.1
Using the right bait in a trap is critical. Protein baits are most effective in the spring and summer. The foraging yellowjackets need the protein in order to feed their young. Canned white chicken meat is a very successful protein bait, preferred over pet food and fish.5
In the late summer and early fall, the yellowjackets prefer sweet baits. Sweet drinks like sodas or juices are effective.2 The highly successful trapping program at the Waterfront Park baseball stadium used a mixture of beer and diluted Italian soda syrup.6 Commercial baits are also available.
There are several ways to kill wasps after they’re trapped. You can put traps in the freezer or put them inside a plastic bag in the hot sun for several hours. You can also submerge them in a bucket of soapy water.7
Traps need to be emptied and refilled with bait at least weekly.2
Trapping queens in the late winter to early spring can reduce the number of nests later in the season.1
Removing a Nest
Removing a nest is a chore that should be tackled only by professionals with expertise in working around stinging insects and protective clothing.7 Aerial nests can be removed at night by enclosing them in a plastic bag and pulling them loose. Other kinds of nests can be vacuumed out.7 Some companies provide this service inexpensively because they sell the wasps as a source of venom to pharmaceutical companies.7 Check out Bee Removal Source for an extensive list of resources organized by state.
If You Think Pesticides are Necessary
NCAP does not recommend the use of pesticides. However, we recognize that you may feel that you have no other options. If you feel that yellowjacket pesticides are necessary, consider using one of the products that the U.S. Environmental Protection Agency has classified as minimum risk pesticides.
For examples: http://www.saferbrand.com/ or http://www.ecosmart.com. These “minimum risk” products do not have a registration number and identify all ingredients on the labels of the products.8
Although they are useful insects, yellowjackets can also be a painful pest. You can solve your yellowjacket problems without pesticides by reducing attractive food or drink and trapping when necessary.
- Mussen, E.C. and M.K. Rust. 2012. Pest Notes: Yellowjackets and Other Social Wasps. U.C. Statewide Integrated Pest Management Program. http://ipm.ucanr.edu/PMG/PESTNOTES/pn7450.html
- Landolt, P.J. and A.L. Antonelli. 2003. Yellowjackets and Paper Wasps. Washington State University Cooperative Extension. https://s3.wp.wsu.edu/uploads/sites/1384/2016/07/Yellowjackets-and-Paper-Wasps.pdf
- Sacramento-Yolo Mosquito and Vector Control District. Undated. Yellowjackets and Paper Wasps. https://www.fightthebite.net/education/yellowjackets-and-paper-wasps/
- Anderson, M. 2016. Avoid Painful, Often Dangerous, Encounters with Yellow Jackets. The EPA Blog. https://blog.epa.gov/2016/09/28/avoid-painful-often-dangerous-encounters-with-yellow-jackets/
- Rust, M.K. et al. 2010. Developing Baits for the Control of Yellowjackets in California. University of California Riverside, Department of Entomology. https://www.pestboard.ca.gov/howdoi/research/2009_yellowjacket.pdf
- Goldstein, M. 1996. Program hits home run. Pest Control (August):44-46.
- Daar, S. et al. 1997. IPM For Schools: A How-to Manual. U.S. Environmental Protection Agency. https://nepis.epa.gov/Exe/ZyPDF.cgi/94003Q78.PDF?Dockey=94003Q78.PDF
- 40 Code of Federal Regulations 152.25.