When I was in elementary school, I was part of a group of kids assigned to raise and lower the American flag every day. There was something exciting about the ceremony of it all: lifting the flag up the pole, learning the proper way to fold and store the Star-Spangled Banner, and working together with such care to make sure no part of it touched the ground. It’s a memory that comes back to me most often on holidays when raising the Stars and Stripes feels especially meaningful, such as Memorial Day, Independence Day, Labor Day, Veterans Day, and, of course, Flag Day.
June 14th is Flag Day, a holiday that recognizes the original adoption of the United States flag in 1777. While it is not an official national holiday, and may not come with the same fanfare as Independence Day, it is still a fitting time to bring out Old Glory and let it wave in the warm summer air. Like many homeowners, you may not fly a flag all year long. Between following the proper guidelines, such as making sure the flag is always lit by flying it only during daylight hours or using a dedicated spotlight at night, and keeping an eye on the weather so it is not left out in rough conditions, it can start to feel more like a task than a celebration of the U.S.A. Still, many Americans have a flag stored away and ready for the right occasion. With Flag Day coming up, you may find yourself heading into the garage or shed to pull it from your outdoor storage area. As with any trip into a storage space, it is a good opportunity to look around for signs of pest activity. That is especially important as summer gets underway and pests that may have spent the winter in or around your home become more active and start reproducing.
As you step into your garage or shed, check the corners, particularly near the ceiling, for spiderwebs or wasp nests. Watch for spiders darting away when you open the door, pull out a drawer, or move a box while looking for your flag. Be mindful of wasps buzzing irritably near your head as you pass through the entrance. Pay special attention if you spot unusual mud formations high on walls, ceilings, or tucked into other sheltered areas, as these can be a clear sign of dirt dauber activity. While dirt daubers may not be the most frightening wasps to come across, if allowing the flag to touch the ground feels like sacrilege, then allowing dirt daubers to take over your home is certainly its own kind of desecration. Thankfully, it does not have to remain that way for long, because The Bug Dude is here to help restore your home to a place worthy of veneration.
What do Dirt Daubers Look Like?
Dirt daubers, also called mud daubers, are a general name for several different species of wasp. Each species has its own appearance, ranging from solid black, to black and yellow, to an iridescent blue-black, but they all share one noticeable trait: a long, narrow waist section that connects the thorax and abdomen. Most of these wasps are between 1/2” and 1” long and often have dark reddish-brown wings. At first glance, they can be easy to confuse with other types of wasps, but there is one feature that makes a dirt dauber problem much easier to recognize: their nests.
What does a Dirt Dauber Nest Look Like?
The exact appearance of a dirt dauber nest depends on the species, but all of them share one common feature: they are built from dirt, which is where the wasp gets its name. The construction process is generally similar across the different species. After mating, the female dirt dauber selects a nesting location and begins collecting small balls of mud to build her nest. Once the first cell is formed, she starts hunting for spiders. When she catches one, she paralyzes it, places a single egg on it, and positions it at the back of the cell. She then continues adding paralyzed spiders until the cell is full, which can be as many as 25 spiders. Once the cell is filled, about an hour after construction began, the female caps it off and starts building the next cell. Each dirt dauber nest houses one adult female wasp along with several wasp eggs, which hatch inside the nest, feed on the paralyzed spiders in their cells, and eventually pupate into adult wasps. Once mature, the adult wasp exits the nest, leaving behind a round hole in the cell. If you find a mud nest around your home and do not see those distinct round exit holes, it means the nest is still active.
The most familiar nest shapes usually come from the black and yellow dirt dauber (Sceliphron caementarium) and the pipe organ dirt dauber (Trypoxylon politum). The black and yellow species builds stacked cells that create a rounded nest, often about the size of a fist. The pipe organ species builds vertical, parallel rows of cells side by side, creating a nest that resembles a pipe organ, which is where its name comes from. Interestingly, the third most common dirt dauber species, the blue mud wasp (Chalybion californicum), does not have a distinctive nest shape of its own because it does not build nests from the ground up. Instead, it reuses abandoned nests from other dirt dauber species, carrying water rather than mud to soften and reshape the existing structure.
Where do Dirt Daubers Live?
Dirt dauber nests are most often found in quiet, sheltered places where mud and spiders are easy to access. In natural settings, this usually means areas near cave entrances or beneath rock overhangs. In towns and neighborhoods, they may show up in barns, rafters, protected areas of buildings, and under bridges. Around your home, you are most likely to find them in garages, beneath eaves, on porch ceilings, inside sheds, in attics, or under undisturbed wood and rocks. Because dirt daubers are solitary wasps, as discussed in “Are Wasps Ruining Your Fall Fun? Give Us a Buzz…,” there is only one adult per nest. However, since each nest can contain several young wasps waiting to emerge, it is possible to find a whole cluster of nests in any of these protected areas.
What do Dirt Daubers Eat?
As mentioned earlier, young dirt daubers feed on the spiders their mothers place inside their cells, but different species of these wasps tend to favor different types of spiders. For instance, the black and yellow dirt dauber prefers crab spiders and other small, colorful spiders, while the blue mud wasp favors black widow spiders. Adult wasps mainly feed on liquids, including plant nectar, honeydew from aphids, and body fluids from the spiders they catch. Because spiders play such an important role in their survival, it is worth remembering that areas with heavy spider activity can attract dirt daubers as well. At the first sign of a spider infestation, contact The Bug Dude at 800-310-BUGS (2847) to have a technician come to your home and help stop one infestation before it turns into two or more. And if you are not sure what to watch for when it comes to spiders, take a look at the article “Don’t Let Spiders Ensnare Your New Year.”
Are Dirt Daubers Dangerous?
If they are left alone, dirt daubers are not considered one of the more dangerous wasp species. Unlike yellow jackets, they are not typically known for being aggressive. That said, they can still sting, and if they feel threatened or provoked, they may defend themselves. While they do not protect their nests in the same way yellow jackets do, it is still wise to call The Bug Dude when dealing with any wasp infestation. Doing so can help keep you safe in case a dirt dauber does sting, and it can also protect you from more aggressive insects that may have taken over an old dirt dauber nest. Even worse, you may be dealing with a more aggressive wasp species that has simply been mistaken for dirt daubers. This is particularly important for anyone who is allergic to wasp stings.
How do you Prevent Dirt Daubers?
As with many pests, prevention generally comes down to two key steps: taking away food sources and reducing places where they can live. For dirt daubers, removing food sources begins with contacting The Bug Dude about a regular service plan to help keep spiders from becoming established in your home. Another important step, which helps reduce both food sources and nesting areas, is sealing potential harborage spots around your home, including cracks, holes, and other openings. You can also make your property less appealing to these wasps by draining areas of excess water in your yard, which helps prevent the mud they use to build their nests.
How do you Eliminate Dirt Daubers?
When a pest problem appears, the safest, most effective, and most efficient choice is to call The Bug Dude at 800-310-BUGS (2847) as soon as you notice the first signs of trouble. Whether you are spotting spiders, spiderwebs, dirt dauber nests, or wasps, reaching out to The Bug Dude early can help get the problem under control and let you get back to enjoying your summer.
This Flag Day, as you proudly raise the Stars and Stripes, let it be a celebration of freedom in two ways: freedom as a nation and freedom from pests.
Further Reading:
“Mud Daubers” – Field Guide to Common Texas Insects – Texas A&M AgriLife Extension
“Mud Daubers” – Texas Apiary Inspection Service (TAIS) – Texas A&M AgriLife Research
“Mud Daubers” – Missouri Department of Conservation
“Open Pipe Mud Daubers” – PestWorld.org – National Pest Management Association
