Yellow Jackets: They arrive in late summer, turning your barbecues and picnics into fierce swatting contests. If you make the scary mistake of stepping on one of their ground nests, you can end up being chased for up to a quarter mile by a squad of angry, yellow-stripped barbed missiles intent on inflicting serious bodily harm. Joking aside, they have been known to kill people and animals when they attack in full force.
Yes, the yellow jackets are back, and about this time of year bee forums are buzzing with concerns about keeping bee hives safe from the black-and-yellow death that is the yellow jacket. Each year, in my western Washington area, beekeepers lose hives to these hungry creatures, sometimes in a matter of hours. I can think of few things as horrid for a beekeeper as coming home to a hive that was thriving only hours before, to find it crawling with thousands of yellow jackets, bees all dead or devoured, honey plundered.
Although consistently mislabeled “bees” by the media—thereby giving our gentle girls an unwarranted reputation for meaness—yellow jackets belong to the wasp family. Like honey bees, yellow jackets are social insects who build large nests to rear their young. Unlike honey bees, yellow jackets generally do not overwinter in their hives, leaving the next generation to the late-summer, newborn queens who will mate and then hibernate in some protected nook through the winter months.
Come late fall, the yellow jacket workers and old queen perish, and the nest is abandoned and not used again. So these wasps need to build up quickly in the summer months, exploiting many sources for food. Adult yellow jackets eat sweets: fruit, nectar, your picnic watermelon. They gather protein for their young: insects, your bees, your hotdog. Come late summer when many new queens are being reared, the need for protein in the hive increases, and this is when you find these wasps around your beehives and barbecues.
So, now that I have your hair standing on end, let’s back up a bit, take a deep breath, and unpack this potential threat to your bees.
First, before you consider management options for these wasps, you need to know what is—and is not—a yellow jacket. All around the country live a variety of of paper wasps. These unassuming garden helpers are often called “umbrella wasps” for their habit of creating small nests under eaves, porch railings, or bush branches that look like a small, paper umbrellas with hexagon cells beneath. This is not the beginning of a huge yellow jacket nest. It is the full-sized home of these black and yellow creatures who raise a small nest of perhaps a hundred baby wasps.
Umbrella wasps are remarkably unaggressive, stinging only when sat upon (ask me how I know), grabbed, or if you seriously threaten their nest. I have untold numbers of these wasps dangling their small parasols from the roof of my bee shed, and they live comfortably and peacefully with our honey bees. Sometimes in the early spring, I find them nestled next to the hive entrance, soaking up the warmth emanating from within. If I find them inside on our windows, I carry them bare-handed outside, but if the day is cool, they will snuggle in my palm and resist leaving. I love these little gals and shudder when I see photos of them posted on bee sites under headings like “Yellow Jackets! Kill the bastards!” I always post a reply: “Please, know your wasps…”
Above is a photo of a paper wasp and a yellow jacket. Note the thick body and shorter legs of the yellow jacket, and her flatter wings. She also has a thicker waist, and is considerably larger over all.
Perhaps you have had bee hives for a few years and have noticed that yellow jackets target one hive over another. How do they determine which hive, which bees, to plunder? Like our honey bees, yellow jackets are governed by pheromones. They use chemical cues to target a hive.
In the scent that wafts from the hive entrance, yellow jackets can read evidence of weakness, illness, stress. If they detect such scents, they will then attempt to enter the hive. If they are able to get past the guards fairly easily, they will crawl up the face of the hive, mark it with a pheromone, then leave to bring back thousands of reinforcements.
If the hive radiates the aromas of strength and robust health, the yellow jackets will work the ground around the hive in groups of two to ten or more, scavenging dead and dying bees, and occasionally grabbing bees on the entry board or in flight.
Recently, I was talking to my friend and bee guru Michael Joshin Thiele (www.gaiabees.com) about yellow jackets in his part of the country (Northern California) and Michael said this: “Susan, yellow jackets are not a predator of the honey bee. They are an indicator species. Yellow jackets attack the weak hives.” I found his information confounding at first, as I’ve had many beekeepers tell me that their strongest hive was decimated by yellow jackets, but I have come to believe that we are not as sensitive as yellow jackets to the true health of our hives. We can’t judge health at the pheromone level. At least I can’t.
Yet I would add this caveat to Michael’s observations: These days, all our bees are weakened to a greater or lesser extent. All of them. So in these times, I consider yellow jackets a danger. Anything from a queen failure to varroa, to viruses, to the stress of hive relocations, new queen insertions, honey collection, heavy pesticide residues, and more can make a hive a target.
By knowing the habits of yellow jackets, we can learn to manage them, and limit their destructive capacities. These tips will keep your hives safe:
Get the Queens
In early spring, yellow jacket queens are searching for nesting sites. Yellow jackets have a much smaller foraging radius than honey bees—only around a thousand feet—so these queens you see in spring are looking to make a home close by. Any yellow jacket queen you dispatch means 10,000 less wasps at your hive entrances. In my yard, I find them visiting my bee watering sites or honey feeders. Friends find them in woodpiles, or even nestled beneath hive lids.
Wherever I find them, I act fast. I don’t hurry to find a swatter. I mash them with my fingers. So far, I’ve never been stung this way. They have to curl their tails up to sting or reach upward to bite. If I smash down, they are done. Less violent means of extermination include yellow jacket pheromone traps you can get at any hardware or garden store.
Fake Them Out
Wasps, including yellow jackets, are very territorial, and will not choose to build nests where other wasps have built. Knowing this, you can create (or buy at any garden store) fake hornet nests that mimic the balloon-shaped paper nests of bald-faced hornets. The favorite food of the bald-faced hornet is yellow jackets! I’ve read that in areas with high yellow jacket populations, the paper coating of the huge hornet nests is a greenish yellow—the yellow being the coloring from the bodies of yellow jackets.
Two years ago, my granddaughter Taylor and I made a hornet nest from a balloon, butcher paper, and wall-paper paste. We painted it with water color paints, and my crafty friend Debbie made a few fake hornets out of polymer clay, which we wired to the “nest.” I hung the nest under the cover of the bee yard, and took it down in the late fall. This spring, I hung the nest out again in a different spot. I don’t know if I can totally credit this craft project with the success I’ve had, but I’ve had very few yellow jackets in our yard these past two years.
Become a Quick Draw
To take care of small clusters of yellow jacket marauders who appear at my hives, I keep a bottle of half water, half dishwashing liquid up in the apiary. I’m a pretty good shot with this water gun, and one squirt with the soapy water interferes with a wasp’s ability to breathe. They die in seconds. So, on hot Indian summer days, I play Billy the Kid up in the apiary.
Or Just Use Traps
It is simple to make or purchase yellow jacket traps. But if I find that I am catching hundreds of the critters, I start looking around my yard for hidden nests, and I ask my immediate neighbors to search their yards, as well. One year—before the making of my balloon wasp nest—our dog Mazel Tov was unlucky enough to find a huge nest of yellow jackets behind an old honey suckle vine. By the time I got him into the house, we were both covered in stings. Did I tell you that—unlike honey bees—yellow jackets can sting over and over again? And bite, too?
If You Find a Yellow Jacket Nest
There are lots of tried and true ways to destroy a nest of yellow jackets. The most effective is a professional exterminator, which is what I use when I find them. Others have successfully poured hot soapy water into the ground nests. Some pour gasoline or kerosene into the hole, and then light it. This scares me. The yellow jackets are bad enough. I don’t need explosions in my back yard.
Another eradication method involves simply placing a clear glass bowl over the nest, making certain that the edges are snug. If the nest has only one entrance/exit, the wasps will try over and over to leave the nest and will eventually expire in the heat.
Because yellow jackets bring home food to the hive, it is possible to place tainted baits that will destroy the colony when these morsels are carried home. One method is to place out meat (bacon, cat food, tuna, or chicken are all good choices) and lace the bait with baking soda, which will wreak havoc with the wasp digestive system. Be sure these lures are out of reach of your pets.
Another fatal bait lure is meat mixed with one packet of Front Line-brand liquid flea treatment. It contains a chemical that kills yellow jackets very quickly. Again, be darn sure it is not accessible by anything but the yellow jackets. My brother tried this a few weeks ago, hanging a can of laced tuna from a thin tree branch in a net bag. The yellow jacket nest was no longer active by the following morning. This is a potentially dangerous undertaking if you do not think it through. You do not want your pet or some harmless wild creature killed.
For all our fear of them, it pays to remember that wasps and hornets are extremely beneficial insects. They carry off debris, clean up fallen fruit, hunt many of the bugs and insects that munch in our gardens, and keep insect numbers in healthy balance. They really are the good guys.
The first best choice in life is always benevolence. If your yellow jacket numbers are not posing a threat to your hives, try the live-and-let-live approach. Graduate to more destructive methods only if you need to. Just like our bees, yellow jackets are just small creatures trying to get by in a difficult world.