Enjoying a meal outside in late summer can be nearly impossible if yellowjackets or other wasps have taken up residence nearby. They eat your food and can be aggressive. Yellowjacket behavior makes them difficult to love, but remember that they are an important part of the ecosystem, too. Yellowjackets feed their young large numbers of insects that might otherwise damage trees or crops. They also feed their young houseflies, and lots of them. This means that when nesting in areas of little human or animal activity, just leave them alone. For areas near your home, try these steps to reduce populations.
By late summer, nests are already well established. Mint is a natural wasp repellent, so next spring try planting mint near the house and using a peppermint oil spray on the eaves to keep yellowjackets from moving in. For the rest of this summer, prevent drawing yellowjackets toward your outdoor activity when possible.
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. Keep a tight lid on garbage cans.
Avoid behavior that attracts yellowjackets. Avoid perfume, hair spray, or other scented body care products. Don’t wear bright red, orange, or yellow clothes. Yellowjackets seem to be attracted by these colors.
Avoid taking action that angers yellowjackets. Stay away from their nests as much as possible. 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.
Traps can be an effective, pesticide-free technique for managing yellowjackets.
Traps can either be purchased or homemade. The video above shows an example of a commonly available trap, used in August near our Eugene, Oregon headquarters.
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.
Using the right bait in a trap is critical. Protein baits are most effective in the spring and through August. The foraging yellowjackets need the protein in order to feed their young. In the late summer and early fall, yellowjackets prefer sweet baits. Sweet carbonated beverages or syrup mixed with water work well.
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.
Traps need to be emptied and refilled with bait at least weekly.
If you’re trapping to reduce yellowjackets at an event, start trapping at least two weeks before the event.
You are unlikely to trap a queen in late summer, but keep in mind that next year, trapping in the spring can catch a queen and prevent an entire nest of yellowjackets.
Synthetic bug sprays kill other beneficial bugs and can be harmful to humans as well. If you want to use a spray against flying yellowjackets or a nest, several botanical oil products are available. Look for one with peppermint oil and a surfactant as active ingredients.
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.
Removing a nest is a chore that should be tackled only by professionals with expertise in working around stinging insects and protective clothing. 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. Some companies provide this service inexpensively because they sell the wasps as a source of venom to pharmaceutical companies.