Eastern yellow jacket cleaning itself on a leaf
Recently I wrote a blog post about bees, wasps and hornets and how to tell the difference. To add interest to the story, I created a graphic featuring 4 common species and asked my readers to identify them. One reader labeled three of them correctly and labeled the fourth one ‘jerk.’ (Actually he used more colorful language, but this is a family blog). That ‘jerk’ was the yellow jacket.
I couldn’t agree with him more. This time of year yellow jackets are everywhere flying in their distinctive back-and-forth pattern and disrupting our outdoor living. The smallest whiff of sugar and they arrive en masse, honing in on the target with a single mind. As we know only too well, kill one of them and you risk alerting the entire gang who swarm to the defense, eager to inflict pain on their prospective victims.
Which leads me to ask: Do yellow jackets have a purpose? What are they good for, anyway?
Yellow jackets are wasps, not bees
It might surprise you to know that, although they resemble some bees, yellow jackets are in fact wasps. A social species, they can be identified by their bright yellow and black markings, slender, hairless bodies and preference for living in large colonies underground.
A yellow jacket collecting nectar from a flower
Although they sometimes build their hives inside a dense bush or wall cavity, Eastern yellow jackets (Vespula maculifrons) and Western yellow jackets (Vespula pensylvanica) prefer to nest in soil cavities such as abandoned rodent holes or tree stumps that they enlarge as they grow. This can pose a threat to our homes and gardens and make lawn mowing hazardous as the slightest disturbance can spark an attack, unleashing them in droves.
And the holes can be hard to locate. Entrances tends to be very small, or roughly the size of a nickel.
Yellow jacket emerging from a nest underground
At our Master Gardener demonstration garden in Maryland, we recently made a painful discovery. Tucked away in an abandoned hole adjacent to our shade garden was an active yellow jacket nest. A couple team members accidentally disturbed it while digging. Each paid dearly with multiple stings.
They sting and bite, too
Unlike honey bees, yellow jackets don’t die when they sting you. This allows them to sting repeatedly using a lance-like stinger equipped with little barbs. They are also known to bite, which enables them to better grab hold to insert their stinger.
Are they good for anything?
Unfortunately, yes. Yellow jackets are predatory insects . They may not help pollinate, but they perform an important function that benefits our plants. They eat garden pests and help control them. As such, many consider them beneficial to agriculture.
Yellow jacket on butterfly weed
Yellow jackets like a good barbecue
A yellow jacket diet is heavy in foods humans are nowadays told to restrict: that is, meats, sugars and carbohydrates. In middle summer, when they are busy feeding their larvae, adults generally forage for food rich in protein including meats, flies, caterpillars and other insects.
As the summer wears on, however, and food sources begin to diminish, adults shift more towards sugary foods such as flower nectar, tree sap and honeydew produced by aphids and scale. Unfortunately, this also includes many of the items we enjoy consuming outdoors, including fruits, juices, beer and soft drinks, not to mention blueberry pie.
Sugars, in fact, are key to developing queens in late summer who must start next spring’s nest. They are the only members of the colony to survive and will need energy to ride out the winter.
So the good news is that, with the exception of the queen, yellow jackets only live for one season. Cold weather will naturally get rid of them. If you can wait things out, worker wasps will usually be dead by the beginning of November.
However, there are those situations that require immediate action, especially when nests located close to houses pose a threat to family safety, or in the case of our garden, are situated behind one of the main visitor benches.
Following are some generally accepted methods of removal of yellow jacket nests. In all cases, it is IMPERATIVE to wait until nighttime when the wasps are back in the nest and less active. And never shine a flashlight or headlamp down into the hole while eradicating them. Yellow jackets will vigorously defend their nests and attack you in droves.
Eradicate yellow jacket nests in the evening
There are a number of registered insecticides on the market for removal of yellow jacket nests. Insecticide dusts are some of the most effective. The dust is applied to the nest opening. The wasps pick up the dust on their bodies and transport it back to the nest, killing the rest of the brood.
Non-poisonous spray mixtures and boiling water
Non-toxic substances such as mint oil or Dr. Bronner’s Peppermint Soap coupled with boiling water have proven effective when poured down the hole.
Seal off the entrance
Not the best choice, since this often forces the wasps to chew their way to another location.
This may take a few applications, but eventually solved our problem at the demo garden. Amazingly, one of the team members whose arm tripled in size after she was stung suggested this less invasive method. She arrived in the evening armed with two large bags of ice and poured them down the hole. We haven’t seen a yellow jacket since.
Have another method you’d like to recommend? I’d love to hear from you. Leave your comments below!
All photos by Shutterstock