These may be the most feared and misunderstood of all the insects that coexist with us in our backyard ecosystem.

There are many species of wasps, hornets and yellowjackets. This article will cover the three that our clients call us about most often. Not too many people care to identify which kind of wasp or hornet is invading their space, or flying around them in a threatening manner, but they can usually be identified by how and where they build their nests.

The queens are the only individuals that survive the winter. They emerge in the spring from overwintering sites (under bark flaps or protected dry cavities – natural or manmade).

The queens are referred to as “foundresses.” The ones we see in the spring are seeking a suitable site to construct a nest or have found a site and are gathering building materials. Sometimes, more than one queen can be observed working on the same nest. These additional individuals are queens that lost the fight for dominance and “behaviorally” have been relegated to the role of a worker.

Paper or Umbrella Wasp

In the spring, the most common and usually the first “hornet” found hanging around the outside of the house is the paper or umbrella wasp. It is called an umbrella wasp because of its characteristic nest. The nest is constructed of a paper-like substance that is a combination of chewed wood and wasp saliva. The nest hangs from a horizontal surface, supported on a single paper stalk with a single row of downward pointing cells.

Paper wasps are what you think as normal size “hornets.” They are dark in body color with dull yellow or orange markings. Like all wasps, hornets and yellowjackets, paper wasps are ecologically beneficial to the backyard environment. They feed on a variety of insects and other invertebrates. They also have a sweet tooth later in the summer. They will seek out sweet secretions from fruit trees and other sources. Because of this they are probably more common in backyards that have fruit trees or heavily used decks or patios.

Bald-Faced Hornet

The nest of the bald-faced hornet is common and easy to recognize. Although other species build aerial nests, the large, gray, hanging nest of the bald-faced hornet is a common sight. The “bloated volley ball” is covered by a sheath of paper-like material. Contained inside are many rows of combs containing the developing larvae. These nests are often found hanging from tree limbs or branches and go unnoticed until the leaves start to fall in autumn. Bald-faced hornets will also make nests under house or garage eves, on deck railings or under any other horizontal surface you might find in your yard or garden.

The bald-faced hornet is a little larger than the paper wasp. The color is basic black accented by ivory white markings. The white marking on the hornets face gave rise to its common name.

Bald-faced hornets fill a role in nature similar to yellowjackets and paper wasps. They are predators of insects and other yard and garden creatures of similar size.

Yellowjackets

The most familiar yellowjacket in Michigan is perhaps the German yellowjacket. Nests are usually constructed underground. The spring queen seeks out abandoned rodent burrows to construct her paper nest. Nests can be found by observing the flight pattern of the yellowjacket. They will land on the ground and disappear! A closer look will reveal a tunnel. Yellowjackets are smaller than most hornets and wasps. They also appear to be stouter in the shape of their body. They are distinctively black and yellow in body color.

Yellowjackets are predators, just like bald-faced hornets and paper wasps. They will actively scavenge any source of animal protein. They are commonly seen buzzing around garbage. Late in the summer they also acquire a sweet tooth.

Controlling Wasps, Hornets And Yellowjackets

Have you or anyone else been stung in your backyard?

Are you allergic to wasp or hornet stings?

Do wasps or hornets in your yard seem to be aggressive?

Have wasps or hornets built a nest in or on your house or garage?

Unless wasps, hornets and yellowjackets become a threat, we urge you to leave them alone. They play an important role in the ecological balance of your backyard, neighborhood and local community.

Having said this, if they must be gotten rid of, there are two aspects to controlling wasps, hornets and yellowjackets: elimination and prevention.

Elimination

If you decide to tackle this project yourself the most important thing to remember is to not risk your personal safety or health. These colonies may be very large (perhaps several hundred individuals) and their location may be accessible only by using a ladder. Wear protective clothing. These insects sting and their venom packs a pretty good wallop.

If you decide to treat the colony with an insecticide only do it at dusk or dawn when their behavior is the most docile. Once the treatment is applied, plug the hole and get out of there. Observe the colony for activity. If there is still activity after a couple of days repeat the treatment. If you must climb a ladder to apply the treatment, take the proper precautions.

There are a variety of insecticides available that are labeled for control of wasps, hornets and yellowjackets. These insecticides come in either a dust or liquid form. If you want to use an insecticide dust it can be applied from a plastic, dry squeeze bottle (dish detergent type) to squirt the dust into the nest opening. You will definitely want to test the bottle before you approach the nest to make sure it’s going to work. The other option is to use a liquid insecticide and spray it into the opening.

Keep in mind, with either of these options you’re lugging extra items up a ladder, so think about how you’re going to actually make the application. Also, if you’re spraying or dusting above your head then it’s likely some material might come raining back down on you – so wear protective eye, mouth and nose protection. And, don’t forget to bring something (cloth, tissue or paper towel) to plug the hole or you’re likely to have a lot of angry, stinging insects descending on you very quickly. Be aware that some liquid products will dissolve the nest so the entrance hole might get enlarged if you are spraying a bald-faced hornet nest.

The other option, of course it to contact a company that offers perimeter pest control and let them spray the wasp, hornet or yellowjacket nest. But keep in mind, just like if you were doing it yourself, it might require more than one visit to totally eliminate all the insects in the nest.

Prevention

Keep garbage cleaned up. Caulk cracks and crevices to prevent yellowjackets from nesting in your house or garage. Do not caulk cracks and crevices of active nests! This may cause the colony to eat a hole into a living area inside your home.