The wasp dilemma: Can you peacefully coexist, or will you need lethal force?

When staff from the N.C. Cooperative Extension program went to Cumberland County last August to teach second-graders about bugs, they had an end game in mind. In addition to fulfilling a federal educational requirement for children of Fort Bragg families, these day-camp lessons were also an investment in the biological health of the planet.

Urban entomology professor Mike Waldvogel and others developed the curriculum to teach kids about the life cycles of insects – which insects are considered pests, and alternative ways of keeping certain insects out of homes and schools with little to no use of pesticides. The method is known as integrated pest management.

As someone who gardens for wildlife, this sounded like a great approach for keeping plants pest-free and wildlife safe at the same time. But not all pests are equally suited to the practice, as I found out recently when I stepped out on my deck to find hundreds of angry yellow and black bees swarming all around me. My dog was stung, and I was, too, three times on the foot.

Once I had retreated back inside and applied medicine to my stings, I remembered that the first stop in IPM pest control is to accurately identify the insect of concern and learn about its potential to harm plants and animals, as well as its benefits. Knowing what creatures eat and what eats them – as well as their reproductive and nesting habits – can help determine how to control or encourage certain species.

Uh-oh, we have wasps

My husband did a little research and figured out that what we had was not a swarm of bees, as I had surmised, but a colony of wasps – most likely yellow jackets, which are yellow and black, but with a thinner waist than the bee.

These especially aggressive insects make nests in the ground and tend to attack en masse when disturbed. Yellow jackets can sting multiple times, and they also emit a scent that encourages others in the colony to attack. The stings are quite painful, but can also be dangerous – potentially life threatening to people with allergies.

As my stung foot began to swell, the word “pest” was perhaps the most polite name I called these uninvited guests. My first instinct was to reach for the Raid, spraying several that had come into the house with me, as well as sending a blast to the area where I suspected a nest.

Feeling a bit remorseful, I later contacted Waldvogel about my dilemma and he offered a bit of sympathy.

“Biting and stinging pests are often not the best ones for discussing IPM because they can pose an imminent health risk for people and pets,” he advised.

So I did more research.

Wasps play a beneficial role in the garden by controlling populations of insects such as caterpillars that harm plants. According to Mother Earth News, a colony of yellow jackets can take out more than two pounds of garden-munching insects in a 2,000-square-foot space.

The down side is, of course, their aggressive nature and the ability to sting, potentially injuring people and pets.

Waldvogel urges a thoughtful response to stinging or biting insects, asking first: How imminent is the threat?

“People think any nest should be destroyed, but if there’s a hornet nest up in a tree and it doesn’t pose a hazard, then leave it,” Waldvogel said. “They eat a lot of caterpillars we don’t want chomping on our garden.”

However, a nest of aggressive wasps near the back door surely poses enough of a threat to warrant some action.

Send them on their way

Among IPM-approved treatments is blasting the site with a water hose at first sign of the nest, then repeating the treatment over several days until the nesting process is disrupted and the wasps seek out safer territory. Too late for me, as this wasp colony I observed is already large and well established.

Another option is to place a translucent cover on top of the nest, such as an inverted glass bowl, to trap them inside. The clear glass is confusing and discourages them from digging out through another location. In my particular situation, with wasps finding a home in the crawl space underneath my deck, that would likely put me at risk of more stings. In addition to the pain, allergies are more apt to occur the more times someone is exposed to the irritating substance.

Another strategy is the use of wasp traps. Whether purchased at gardening stores or homemade, traps have the potential to wipe out wasps without damaging other beneficial insects or garden plants. Directions on carrying out this treatment, which lures the wasps with sugar or protein, are available at rodalesorganiclife.com.

The track record on this technique is sort of hit or miss. Waldvogen says that for some reason, yellow jackets in North Carolina seem less likely to fall for the bait-and-trap solution. Thinking it might be worth a try, I caught several hundred in one day this way. Continued daily use might eventually do the trick.

A final option

If not, that leaves me with just two options: staying off the deck for the rest of the summer or using an insecticide spray or dust. Option No. 1 does not seem realistic, so on to No. 2.

Lots of pesticides are on the market for use against wasps, with Bayer, Ortho and Spectracide the most popular, Waldovogen says. These must be sprayed or dusted directly on top of the nest entrance. To lessen the chance of getting stung, it’s best to apply the treatment at night, when wasps will be huddled in their nests and not very active. Wear head-to-toe protective clothing, including a face net, while doing this.

Hiring a pest control professional is obviously a safer option, although not all companies want to deal with a yellow jacket nest – and those that do don’t come cheaply. My quote from Orkin for a one-time treatment guaranteed for 30 days was more than $300 – whew!

Other tips

While I continue to struggle with my own pest dilemma, I wanted to share what I have learned as well as offer some tips for preventing wasp nests and stings gleaned from various sites on the internet.

▪ Remove food sources. Wasps are attracted to protein foods in spring and early summer as they raise their young. In late summer and early fall, wasps prefer the energy provided by sweets, such as colas or fruit juice. Cover garbage cans and make sure to properly dispose of any food scraps. Keep drinks covered while outdoors and avoid areas with fruit trees.

▪ Install a nest decoy. These paper contraptions take advantage of the wasp’s competitive nature, discouraging real wasp colonies from settling nearby.

▪ Avoid swatting. Swatting at wasps causes them to release a pheromone that agitates other nearby wasps. If you see one or more wasps hovering nearby, slowly walk away.

▪ Minimize use of strong scents and bright clothing. Wasps are attracted to sweet smells and bright colors, especially in late summer.

▪ Discourage nesting. If you have locations that have attracted nests in the past, such as birdhouses or fence rows, tape up some aluminum foil and/or rub the area with dishwashing detergent or bar soap. While colonies do not return to the same spot annually, a prime nesting location might be re-used by others the following year.

This story was originally published June 30, 2017 at 12:24 PM with the headline "The wasp dilemma: Can you peacefully coexist, or will you need lethal force?."