[Stinging Insects] An All-American Insect

Way back in 1982, I achieved a few seconds of my allotted 15 minutes of fame by winning the logo design contest for the first joint meeting of the Entomological Society of America and the Entomological Society of Canada. My conception was to feature a noteworthy insect that would be familiar to all conference participants, perhaps some common but distinctive species that was native to both countries.  But which one? Several colleagues suggested the monarch butterfly, which was subsequently nominated in 1989 as the national insect of the United States, although the legislation failed to pass.
I had nothing against the monarch, but I believed there was a much stronger candidate that deserved to be recognized. My selection was the incomparable Dolichovespula maculata, commonly known as the baldfaced hornet. Stylishly menacing in its glossy black and white suit (sort of like a miniature killer whale) and ranging over the continent from Florida to Alaska, it has earned a place of honor in our culture as the primary architect of those hulking papier-mâché nests that have tempted the sticks and stones of foolhardy children down through the ages.
My artistic tribute to these insects featured a pair of really big ones sitting astride the continent and congratulating each other on their ecological dominance.
Needless to say, our industry has a far more direct interest in this formidable social wasp than we do in monarch butterflies. Since D. maculata has also been one of my principal research subjects over the years, I’d like to briefly review its biology, give some basics on control, and admit to a couple of memorable personal encounters. 

YEAR OF THE HORNET. Like other bees and wasps with an annual life cycle, a fertilized hornet queen spends the winter curled up in some hidden nook, and if she’s lucky enough to survive the experience, starts a so-called “embryo nest” in the spring. Just before the first workers are ready to emerge, she often prolongs the entrance hole into an incongruous tube up to 5 inches long and barely wide enough for her to crawl through (see Figure 1, page 58). Both defensive and thermoregulatory functions have been proposed for this remarkable structure, which is soon removed by her daughters.
When the workers appear, the queen ceases to forage and stays within the nest for the rest of her life. Over the next one or two months, the colony becomes more populous and the single comb, concealed within its protective, multilayered envelope, rapidly expands so that more workers can be reared. The nest material itself, chewed from weathered wood, is water-repellent and astonishingly tough. When the hornets locate their home on one of ours (see Figure 2, page 60) the remnants of its envelope rings can last 20 years or more if left undisturbed.
At some point in midsummer some mysterious chemical switch is thrown and the hornets begin building additional combs reserved for rearing the new queens and males. At its zenith, the nest may measure 2 feet from top to bottom and house a colony of up to 600 workers, although 100 to 400 is more typical. Much of the prey they capture consists of flies and their smaller yellowjacket cousins. Eventually the foundress queen dies, the worker population dwindles, and the reproductives depart to mate. Then when the leaves fall from the trees, folks look up, gasp as they see the nest for the first time, and say, “I can’t believe that thing was there.” The vacant nests that are not harvested as display items for nature centers are ripped apart during the winter by birds, squirrels, and the elements. 

HORNETS VS. HUMANS. After removing several hundred Dolichovespula colonies over the past 35 years, I’m convinced that any high-pressure, rapid-knockdown aerosol labeled for this purpose that you can buy in the drugstore is superior to anything you can mix up in your one gallon sprayer — you just can’t beat the shock and awe produced by the overwhelming volume of product that blasts out of the can. The operation might appear straightforward, but there are several ways that things can rapidly go south. If the job is done during the day, figure on about half of the adults being away from the nest at any given time. For a large colony, that can mean 100 or 200 returning foragers forming an agitated cloud around their poisoned home and zinging crazily through the air when they land on it and touch the chemical. Not to mention dozens of down-but-not-quite-out individuals dropping out of the entrance hole and writhing around on the ground before finally expiring. If there is any reasonable chance of contact between hornets and humans after treatment, then you either need to use a vacuum to remove most of the workers before spraying (see the August 2004 issue of PCT), or you need to treat at night when everybody’s home.
The two main things to remember about treatment after dark are: 1) yes, you still have to wear your full bee suit with gloves and veil, or you will only tempt karma into giving you a really bad evening, and 2) hornets are strongly attracted to light, and the guards in the doorway (or outside on the envelope if it’s a warm night) will immediately fly toward it. So just point the flashlight off to one side while approaching the nest, unload into the entrance hole as soon as you’re in range, and be prepared to turn off the light if need be.
Following treatment, the more quickly you can get the nest into a plastic bag, the fewer dying workers will drop out of it and crawl up your pant leg.
DOLICHOVESPULA DEBACLES. One of my top pet peeves is when I hear some guy (it’s always a guy) talk about a stinging insect job he did that featured totally unprofessional behavior. Not wearing a protective suit is by far the most common infraction, but there seems to be an almost infinite number of ways to ignore common sense and needlessly court danger in this line of work.
On the other hand, who am I to talk? What is it about stirring up a hornet’s nest that turns the most sober and prudent individual into a bona fide yahoo? Here are two of my favorite tales of moronic misadventure with the All-American Insect, starring myself.
The Shaving Cream Caper. Some years ago, a client asked me if I could bag the basketball-sized hornet nest that hung in a shrub in his front yard, so he could stick it in a chest freezer and have his kid bring it to school for show and tell. Understandably, he didn’t want the thing turned to mush with pesticide, so spraying was not an option. Seeing how the nest had expanded around several large branches, I realized it would have to be a two-part operation. During the day I showed up in my bee suit and, while the colony mobbed me with its full fury, quickly clipped all but one of the supporting limbs. Danger to noncombatants was minimal, since the property was out in the country and the family dog was confined indoors for the day. Why didn’t I use a vacuum? I have no idea.
That night I returned with an entomologist colleague, who told me of a brilliant idea he had recently heard at a meeting. First thing you do, he said, is take a can of shaving cream and shoot a gobber of it into the entrance hole. That way, with the hornets safely plugged up inside, you can use both hands to detach the nest and put it into the bag at your leisure. Sounded brilliant to me, so I borrowed a can from my client, crept up to the nest with indirect light, and lathered up the doorway. An angry buzzing erupted from the interior, but the critters indeed could not penetrate the dense foam.  Très slick.
So as my colleague — who had not bothered to suit up — held the flashlight, I stuffed a bag into my back pocket and started to clip through the branch. And the second that branch began to shake, the entire gobber of shaving cream neatly detached in one piece from the entrance hole and fell to the ground. It seemed to happen in slow motion. In contrast, I recall that both the hornets and my colleague moved very, very fast. The client, who had been watching from his window, thought the floor show was well worth the price.
Hornets in the ‘hood. Early in my pest control career, I arrived on a warm summer evening at the home of a customer who had lived with a D. maculata nest up on his fascia board for a couple of months before deciding it had grown just a little too large for comfort. His street was bustling with activity — kids riding their bikes, folks barbecuing on their patios or relaxing on their porches, the usual all-American scene. The hornets were also still in full swing, so it was definitely too risky to apply an aerosol — particularly since I noticed that the critters were entering and leaving through several points in the envelope besides the official entrance hole (not unusual). Under most circumstances, I would have grabbed the vacuum from the truck and done the job the right way. But I got to chatting with the homeowner, and when showtime finally rolled around, it had become dark, lights were turning on all over the neighborhood, and all hornet activity had ceased.
Heck, the nest was hanging right out there on the side of the house. I figured I could just put a bag around it and call it a night. Done it many times before. So I got into the bee suit, climbed up the ladder, bagged the nest, and pulled down on it to detach it from the wall. I’m still not entirely clear exactly what happened next — perhaps therapy might draw it out — but I have a strong mental image of me bobbling the thing and watching it slip (again in slow motion) away from the mouth of the bag.  The nest went splat on the ground and busted open like a ripe melon.
Well, now. You know about not being able to put toothpaste back into the tube? Over the next couple of minutes, yowls of pain and distress echoed all up and down the block as the hornets went berserk, aiming themselves at every light source they could find. From the safety of my bee suit I watched the neighborhood disintegrate into chaos and wondered if this was nature’s way of telling me I needed to switch careers. Without a doubt, it was the absolute worst experience I’ve ever had in the pest control business. It could have ended with somebody getting seriously hurt or worse.  So why does it crack me up every time I think about it?

All photos are © Al Greene/Nancy L. Breisch

The author gratefully acknowledges Dr. Nancy Breisch for being present at the above incident and having the grace and tact not to call me a clumsy oaf.  The opinions expressed herein are the views of the author and do not necessarily reflect the official policy or position of the U.S. General Services Administration.

The author is regional entomologist for the U.S. General Services Administration in Washington, D.C. He can be reached via e-mail at agreene@giemedia.com.