Last summer, we had a colony of bald-faced hornets (Dolichovespula maculata) take up residence on our back deck.
We’re weirdos who are quite fond of insects. Usually, we’re more than happy to have predatory insects around to help us manage populations of pest insects in our organic garden — paper wasps, mantids, ladybugs, lacewing larvae, wheelbugs, Florida predatory stink bugs… our gardens are chock full of both predator and prey insects.
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We see this every year, but it’s always amazing… This large green worm is a tobacco #hornworm, the larvae of the beautiful Carolina sphinx moth. They’re common pests that eat tomato and other nightshade plants (this one was on an Incan golden berry leaf). They’re one of our ducks favorite foods but they’re also a host for the larvae of beneficial predatory parasitoid wasps. The white spots sticking off of the green hornworm are the cocoons of metamorphosing parasitoid wasps. The parent wasps paralyzed the hornworm, laid eggs inside of it, and its larvae made a meal of the worm before forming the tiny white cocoons on its surface, out of which mature parasitoid wasps will soon emerge. Once the tiny adult wasps emerge from the cocoons the predator > prey cycle will start anew. How were our parasitoid wasps able to find the well-camouflaged tobacco hornworm hidden amongst all the leaves? The plant “told” the wasps where to look. As the herbivorous hornworm starts to chew on the leaves, the worm used a chemical called volicitin in its saliva to soften the tissue of the plant. A plant can’t run away, swat at the hornworm or scream for help, but it is anything but defenseless. When the plant’s immune system detects volicitin, a chemical “conversation” begins, although it’s not in the same language that people speak. Instead of crying “help!” the plant began releasing a set of airborne semiochemical compounds to alert predatory insects that there was a meal waiting for them, while at the same time alerting other nightshade plants in the area that a hornworm attack was underway. As a result, the parasitoid wasps were able to easily find their target and other nearby plants in our garden responded to the plant’s warning by boosting their own natural pest-repelling and insecticidal compounds to help them fend off a potential attack. Ecosystems are communities whose members thrive through collaboration, not just competition. Unfortunately for this hornworm, it happened to find itself in a well-guarded, interconnected community. #ecosystem #integratedpestmanagement
However, in the case of bald-faced hornets taking up residence on our back deck, we were a bit nervous. For one, we spend a good bit of time on our back deck, as does Bob the Cat. Bald-faced hornets (which are “aerial yellowjacket” wasps, not true hornets) have a ferocious reputation. Reports of them stinging people abound.
Did we really want 500+ worker hornets in our living space?
First instinct: remove the hornet nest
As the bald-faced hornet nest expanded in size and number of workers, we decided we’d take the hornet nest down.
- Borrow our bee-keeping neighbor’s bee suit.
- Go out at night, cover the nest with a pillow case, and cut it off of our porch overhang.
- Drown the hornets in a bucket or cooler of water (we don’t use insecticides since we eat our yard and have pet ducks who regularly forage around our deck).
Since I love insects, the thought of doing this made me a little sick to my stomach, but it beat having one of us (or a pet) get stung by the hornets.
So we picked up our neighbor’s bee suit and got everything ready for the removal of the bald-faced hornet nest.
Learning about bald-faced hornets
Then The Tyrant and I made the mistake of reading more about bald-faced hornets from various sources, from Wikipedia to entomologists to university extension agencies. Our general philosophy is if we’re going to kill something, we at least have an obligation to learn about it so: a) we know we’re making an informed choice, and b) we know it’s necessary.
We learned more about the social structure of the colony. We learned more about how bald-faced hornets are amazing predators, help control populations of other insects, and also serve as pollinators.
We also found out that bald-faced hornet nests are only active for one season. Before the first frosts and freezes of fall hit, the colony’s queen will have laid new queens that will fly out of the nest, become impregnated, and overwinter. When the weather warms, they’ll emerge to start new nests elsewhere.
All the remaining bald-faced hornets (including the queen) in the old nest will die with the onset of cold weather.
The next day, we returned our neighbor’s bee suit. We decided we’d do our best to coexist with our bald-faced hornets for the remainder of the warm weather season rather than killing them.
Are bald-faced hornets dangerous?
As best we can tell from searching our googler, nobody has ever died due to a bald-faced hornet attack. However, they do aggressively defend their nests, so anyone with small children or severe allergic reactions to their venom might view them as dangerous and prefer not to live near them.
Despite their scary reputation, our colony of bald-faced hornets seemed to recognize us and our cat as non-threatening since we regularly spent time on our back porch near their nest without ever causing harm or coming too close. Many times, I’d go well within 10 feet of the colony to observe them coming in and out of the nest’s single exit/entry hole, often carrying caterpillars and other insects they’d hunted in our garden.
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We’re probably a little nuts, but when we noticed bald-faced hornets forming a colony next to our back porch early this summer, we had a decision to make: Option 1: Borrow our neighbor’s bee-keeping suit and plop the nest into a bucket of water, killing the colony. Option 2: See if we could co-exist with the hornets (technically wasps). Since they’re amazing predators and pollinators, we went with option 2. The colony is now nearing the end of its life cycle. Despite spending lots of time on our back porch, we never got stung or felt threatened by them. They hunted and pollinated our plants all summer long, helping keep pest populations in check and plants pollinated. All the males and workers are soon to die with the onset of cold weather, and a pregnant overwintering female will start a new colony next spring. We’ll move this nest to the woods during winter, and hope to see these insects back again next summer. While we wouldn’t necessarily recommend a strategy of coexistence to anyone in this predicament (especially those with children), it was another interesting learning lesson for us. We’re grateful to be part of such an extraordinary ecosystem, and are glad to provide a little patch of safe habitat in a world where so many insect species are either rapidly declining or going extinct due to habitat loss and pesticide exposure. The experience left us oddly hopeful that human beings will figure out better ways to foster mutually beneficial relationships with other species (even the scary ones) who share this little blue dot with us. #baldfacedhornet #entomology #predatoryinsects #pollinators
What’s inside a bald-faced hornet’s nest
When the temperatures hit freezing last fall, all the bald-faced hornets in the nest died, as expected. We left the nest up over the winter since dealing with it wasn’t high on our priority list. Plus, we were curious to see how the structure held up over the winter without any bald-faced hornet workers to maintain it.
Last week, we used a knife to cut the nest off of the porch overhang and to take a closer look at the structure inside. As you can see in the photos below, it was amazing!
Insects play so many vital roles in nature. They’re nutrient recyclers, pollinators, predators, food for larger organisms, and so much more.
It’s no stretch to say the survival of insects is critical to the survival of human beings. Yet you may have heard about the massive declines in insect populations around the world in recent decades.
Well, here are a few things you can do about it right now…
Have a yard? Recognize it as potential habitat for trillions of above and below ground insects. Grow a diversity of plant species, especially flowering plants, using organic growing methods. In fact, we recommend turning your yard into an organic edible landscape which makes a lot more sense than simply growing grass.
Perhaps most importantly, take an interest in nature (which you’re a part of, not apart from). It’s abso-fricking-lutely amazing what’s happening all around us all the time. We’re often completely oblivious to it because our brains don’t have the knowledge necessary to allow it to come into view.
The more you know, the more you’ll be amazed — and the more likely you’ll be to create environments that have a regenerative ecological impact.
Now buzz along and get our top-10 tips for starting your organic garden, if this approach sounds like a good idea to you…