Wasp, Hornet, and Yellow Jacket Control– An Integrated Pest Management Stinging Insect Action Plan
Wasps, hornets, and yellow jackets are insect members of the family Vespidae, commonly called vespids. Although closely related, bees are a not vespids and will be discussed in a separate article. Members of the Vespidae family are widely varied and diverse; there are approximately 5,000 different species of wasps in the world. Some species live in large groups and other wasps are solitary. Some species of wasps are effective pollinators, while others kill and eat other pest insects. While the sting of a wasp, hornet, or yellowjacket is extremely painful and downright dangerous for some, they have an important role within the ecosystem. Notwithstanding these benefits, wasps, hornets, and yellowjackets need to be controlled when the risk of human interaction is high.
Homeowners deal with three main species of vespids, paper wasps, yellowjackets, and bald- faced hornets, therefore this article will address these 3 species specifically. Before addressing a wasp nest in your yard, arm yourself with knowledge, and create a plan. The complexity of the job is dependent upon the size and location of the nest. Due to these variables, often, safe and proper removal of wasp nests requires the assistance of a Pest Management Professional.
Species: Polistes spp.
Paper wasps are usually between 1/2 – ¾ inch in length. They are black or reddish with red, brown, or yellow markings on their bodies. Unlike a honeybee, paper wasps have very little hair. They have a narrow waist and hold their wings lengthways to their bodies. They fly relatively slowly, and their feet appear to dangle while they fly. Paper wasps are not usually aggressive unless their nest is disturbed or threatened.
Paper wasps get their name from the paper-like feel of their nests. They are sometimes referred to as umbrella wasps because of the shape of their nests. Paper wasps mix saliva with dead wood, leaf stems, and other organic matter, and use this mixture to form their nests. Their nests are usually situated under eaves, in the garage, on branches of a tree, under a dock, and in playground or sporting equipment. Paper wasp nests have a visible honeycomb-like pattern. They use the cells in the honeycomb to raise their young. An average paper wasp nest will hold between 4 and 30 wasps.
Species: Vespula maculifrons and Vespula squamosa
Yellowjackets are easily recognizable by their distinctive yellow and black markings. The patterns of the markings can be used to differentiate between males, workers, and the queen. Yellowjackets are usually ½” in length, have little hair, slender waists, and fold their wings lengthways to their bodies. Yellowjackets are considered by many to be the most aggressive stinging insect. They will sting without provocation, and if their nest is threatened, they will band together and chase the threat… you. Yellowjackets usually fly about 7 miles per hour, however, if they are sufficiently provoked, they can fly up to 30 miles per hour. You probably cannot outrun an angry yellowjacket. Yellow jackets can sting multiple times as they usually do not loose their stinger upon stinging.
Yellowjackets usually nest in the ground, but may build nests in wall voids or trees. Yellowjackets often use burrows from other animals to house their nest. Often the only indication of a yellowjacket nest in your yard is observing the yellowjackets flying low to the ground and entering their inground nest. The nests range from the size of a soft ball to a few feet in diameter. Each nest may hold between 4,000 – 5,000 yellowjackets. In southern states where it does not freeze for an extended period of time, yellowjacket colonies may not die out in the winter. They will grow larger and larger each year. This can result in the yellowjacket nests that often make the news because they are so large they fill an entire abandoned storage shed.
Species: Dolichovespula maculata
Bald faced hornets are in fact not a hornet at all, they are another species of wasp. The term hornet was mistakenly associated with this species because of its larger size and aerial nests. Bald faced hornets are very closely related to yellow jackets and have a similar shape to yellow jackets, but with different coloring. Bald faced hornets are mostly black with three white stripes on their abdomen. Their face is mostly white. Their distinct coloring and patterns have earned them nicknames such as white-faced hornet, white-tailed hornet, bald-faced yellow jacket, black jacket, and bull wasp. Bald faced hornets are slightly larger than yellowjackets at 1/2 – 5/8″ in length.
Similar to yellowjackets, bald faced hornets are aggressive and can sting repeatedly. They will attack even if they do not feel threatened. Bald faced hornets are easily angered by loud noises such as lawn mowers and leaf blowers. As yellowjackets usually build underground nests, bald faced hornets build aerial nests. They form complex nests at least 3 feet above the ground, usually in trees, shrubs, utility poles, on overhangs, or on sheds. These nests usually have the shape of a warped ball and may house as many as 700 stinging insects.
Wasps are social insects, living in colonies of tens (paper wasps) to hundreds (hornets) to thousands (yellowjackets). They defend their nest against threats, such as people and pets who get too close to the nest entrance. Guards stationed near the nest entrances use chemical communication to warn the colony of intruders. When the proverbial alarm is sounded, wasps quickly emerge to protect their nest from the threat.
Wasps usually die out each winter (in most parts of the US) shortly after the first frost. Queens survive the winter by hibernating in sheltered locations like buildings or outdoors under bark, stones, loose leaves or other shelter. In late spring a mated female emerges from hibernation and begins searching for a place to establish her nest. Once she chooses a spot, she begins to chew wood which mixes with her saliva to create her nest building material. She constructs a small nest and lays eggs in the hexagonal shaped cells. As there are no workers yet, the queen, or foundress, rears the first batch of young herself. When they emerge as adults, they become workers and provide food and expand the nest. In warm areas of the country, wasp colonies, especially yellowjackets, may survive the winter. After several years, this results in nests that are several feet across with tens of thousands of wasps.
Wasps are either scavengers or predators of other insects, it varies by species. Some species scavenge for protein rich foods or sweets from trash cans or recycling bins. While ants are generally credited with ruining a picnic, wasps are a common picnic invader, especially in the fall. Many species of adult wasps eat fruit, honeydew nectar, and other sweets. Many gardeners choose to coexist with wasps because they kill so many different pest insects. Wasps eat many different insects including caterpillars, aphids, beetles, crickets, and ants. These insects are chewed up and fed to the wasp larvae that are in the nest.
Each of the three stinging wasps described above create very different nests. The nests are intricate and complex in design. If you find a nest, do not immediately disturb it, but if you can safely get close enough to observe the nest, you may be able to identify the species of stinging wasp. Common areas to look for wasp nests include along your eaves, inside garden sheds or your garage, gaps in your home’s siding, in and around utility boxes or pool equipment, underneath windowsills, under your deck, and in trees.
Wasp nests have a distinctive paper-like feel to them. Wasps chew trees, branches, fence posts, and even cardboard and mix it with their saliva. The saliva breaks down the wood product until it is the consistency of soft paper pulp. Wasps manipulate this material to form intricate nests to house the colony and raise their young. Wasps utilize the honeycomb structure in their nests. The wasp queen lays an egg inside each hexagon shape cell, when they hatch the wasp larvae are housed in their cell.
Paper wasp nests are usually found under the eaves or another protected area such as under play equipment. Paper wasps do not cover the honeycomb structure, so you can easily observe the intricate structure and the wasps themselves.
Bald faced hornets build nests up higher. They are often found in tree branches or on telephone poles. Bald faced hornets utilize the honeycomb structure, but they surround the nest and enclose the structure with their paper-like construction material. Bald faced hornets’ nest look like a misshapen ball or a football.
Yellowjackets are unique in that they sometimes build nests above ground, but often, they create their nests underground. Yellowjackets utilize abandoned burrows of other animals and create their structure underground. Yellowjacket nests can become quite large. In warm frost-free areas of the country, a colony may survive the winter. If a yellowjacket colony continues to multiply year after year the nest can become very large. The most famous instance of these colossal nest is a yellowjacket nest in Alabama which takes up the interior of a 1957 Chevrolet.
The sting of a yellowjacket, bald faced hornet, or even a paper wasp will send your running. Paper wasps are considered to be non-aggressive, but the same cannot be said for yellow jackets and bald faced hornets. These more aggressive species will attack simply because you are present.
How painful is a yellowjacket sting? Entomologist Justin Schmidt willingly subjected himself to venomous stings and rated the pain and meticulously recorded his reactions. His verbiage is poetic, as if he is describing a fine wine. He rates each sting on a scale of 0 – 4. Zero means the sting is “completely benign” with 4 being “mostly dead.” Schmidt rates a paper wasp sting as a level 3 and describes it as, “Caustic & burning. Distinctly bitter aftertaste. Like spilling a beaker of Hydrochloric acid on a paper cut.” With reference to yellowjackets, which he rates as a 2, Schmidt says, “Hot and smoky, almost irreverent. Imagine W.C. Fields extinguishing a cigar on your tongue.” Bald faced hornets, also rated as a 2, Schmidt says, “Rich, hearty, slightly crunchy. Similar to getting your hand mashed in a revolving door.” Keeping in mind that yellow jackets and bald- faced hornets often attack as group and sting repeatedly, the pain inflicted by these insects can be tremendous.
While most wasp stings are accidental, the most important tip for sting prevention is do not harass the wasps. Do not swat at them and do not disturb their nests. Warn children and physically restrict children and pets from approaching a wasp nest that you are aware of. Never walk barefooted in the yard. If you have a play structure in your yard, periodically check the underside for wasp nests.
Wasps are attracted to proteins and sweets. Garbage and recycle procedures should ensure that they are kept covered and cleaned the bins cleaned regularly.
- First, move to a safe location to avoid being stung repeatedly.
- Be sure to observe the patient for any signs of allergic reaction.
- If the patient has a history of allergic reactions, shows signs of severe swelling, or has trouble breathing, a physician should be contacted immediately.
- Often people with known allergies to stinging insects have a prescription to carry an Epi-Pen® (epinephrine). Epi-Pens® can provide critical first aid and prevent anaphylactic shock.
- Inspect the sting carefully and remove a stinger, if one is present.
- If the patient shows no signs of distress, the sting area can be soothed by applying a cold pack to reduce swelling.
- An over-the-counter insect bite and sting product may be applied.
- Home remedies include applying a paste of baking soda or meat tenderizer and water.
- An antihistamine may also be given to relieve the itching caused by the sting.
The goal of wasp pest control should be to reduce human encounters, but not to eliminate wasps from the entire area since they are beneficial predators of insects.
The two most effective and environmentally conscious ways to do this are:
- to modify the habitat to reduce access to food in the vicinity of human activities
- to use physical controls such as trapping and nest removal
More often than not, wasp nests are found because someone has been stung. By keeping your eyes out for wasps, you may spare yourself or family member a painful experience. By inspecting for wasps at the right time, you may catch a nest early, when the wasp population is small. Begin looking for wasps in the spring, when the foundress comes out of hibernation. Search in areas that are conducive to nests, paying special attention to areas where people congregate.
Yellowjacket, wasp and hornet nests can be located in a variety of places including:
- in the ground
- Yellowjacket ground nests are often sheltered under shrubs or other debris
- in masonry or other wall voids
- on the eaves of buildings
- in attics
- on fences or in trees.
In environments where these species occur frequently, a monthly inspection of buildings and grounds for nests during the active season may be warranted, with more frequent inspections during nesting seasons for problem species.
During your inspection, if you find paper wasp start-up nests, they can easily be removed with a pole or stream of water. Since only the queen is present, the stinging risk is much lower than later in the season when large numbers of workers are present.
In certain situations, traps may be a useful tool in your battle against wasps, hornets, and yellow jackets. Traps are usually placed in areas of likely or observed activity and filled with either a liquid or dry attractant. The wasp can enter the trap, but it cannot get out. Trapping is not a substitute for removing the nest and eliminating the wasps, but it may buy you some time and help to prevent an attack. Note that some species, such as the southern yellowjacket, are primarily predators and may be less attracted to traps than other scavenger species.
Trapping would be an alternative if it is determined that the nest is on a neighboring property and the property owner will not remove the nest. You can set traps if, for whatever reason, you are unable to remove the nest promptly. Trapping can also be helpful to monitor the vespid situation at a given location. When used this way, you may learn of a bald- faced hornet nest in its early stages, before there are hundreds to contend with. Hanging a trap in early spring may lure a potential queen and prevent the nest from even starting.
When monitoring or trapping wasps, be sure to place the traps at least 20 feet away from the house or other areas where people congregate. You do not want to lure wasps closer to the pool or playground. If you know where the nest is, place a trap near the nest. If possible, place all traps out of the reach of children and pets.
While traps may have some benefit in reducing numbers of foragers, they are not generally effective in eliminating entire colonies. Captured vespids in traps can be killed by freezing, placing in the sun for several hours or submerging the trap in soapy water.
Eliminating part or all of the items necessary for vespid survival, known as the survival triangle, food, water, and harborage, is key to successful control. Yellowjackets, wasps, and hornets are scavengers and typically become a problem where food and waste handling occurs.
Potential food sources:
- Clean up food and drink spills immediately.
- Store food items to be consumed outdoors in sealed containers.
- Frequent cleaning of trash receptacles.
- Use strong liners for waste containers and recycle bins that do not rip and create spills.
- Tight-fitting lids on outdoor trash cans, recycling bins and dumpsters.
- Empty outdoor trash cans and recycle bins frequently to prevent overflow, ideally in early afternoon and again at dusk.
- Use outdoor waste containers with spring-loaded doors and keep dumpster lids closed.
- Place outdoor trash cans, recycle bins and dumpsters away from building entrances.
- Do not plant flowering trees, shrubs or flowers immediately adjacent to building entrances, walkways or playground areas.
Potential water sources:
- Fix plumbing leaks, gutters that hold water, etc. to eliminate access to water.
- Eliminate harborage areas by sealing openings in exterior surfaces including walls, masonry steps, bleachers, fences, playground equipment, etc.
- Nesting sites can be reduced by capping open fence-pipe ends, and by sealing gaps, holes and other openings into voids in walls, doorways, eaves and roofs.
As previously stated, do not disturb the nest until you are ready to treat it and/or remove it. Special protective gear should be used when attempting to handle a yellowjacket, bald faced hornet, or a large paper wasp nest. Once disturbed, they will ferociously attack, and you should be protected. This gear should minimize stings and ensure a safe and prompt treatment.
Complete body coverage is essential because yellowjackets and other wasps can find even the smallest exposed area. Use clothing designed for beekeepers.
Your suit should include the following:
- A bee suit or loose-fitting, heavy-fabric coverall with long sleeves. This is worn over regular pants and a long-sleeved shirt to provide extra protection from stings.
- A bee veil or hood that either contains its own hat or can be fitted over a light-weight pith helmet or other brimmed hat that holds the veil away from the head.
- A metal-screen face plate that extends around the head. Check the veil carefully for tears before each use.
- Sturdy high-topped boots with pant legs secured over the boots to prevent wasps from getting into trousers.
- Gloves with extra-long arm coverings to protect the wrists.
- Thoroughly duct tape all connections between the bee suit and boots, gloves, veil, hat to prevent yellowjackets from crawling inside. They are skilled at finding even the smallest opening.
Once you have determined that a nest needs to go, it is time to make a plan. Many homeowners decide to call a Pest Management Professional to handle the issue for them. Others take the DIY approach and tackle the problem themselves. If you want to treat the nest yourself, here are some tips to help you have a safe and successful wasp elimination.
When an insecticide is considered necessary for the control of vespids, the best approach is to confine the pesticide to the nest itself. Anyone applying insecticides should use special clothing that protects against the chemical as well as against wasp stings. Insecticides should be applied in the evening when children are absent, the wasps are inside the nest, and cooler temperatures reduce insect activity.
A number of insecticides are registered for use against wasps, including dusts, silica aerogels, pyrethrins, and pyrethroids. Pyrethroid insecticides work well and should pose no significant environmental or health risks when applied directly to vespid nests. Read the label on your chosen products carefully, and verify the nest location is on your product’s label as an approved site (i.e. wall void, in ground ect)
Pesticides must be used in accordance with their EPA-approved label directions. Applicators must be certified to apply pesticides and should always wear protective equipment during applications. Do not apply these materials when buildings are occupied, and never apply them where they might wash into drains or sewers.
Do not use gasoline. Gasoline should never be poured into underground nest holes. This dangerous practice creates a fire hazard, contaminates the soil, and prevents the growth of vegetation for some time. A ground application of gasoline poses greater harm to children and the environment than a wasp nest.
Pesticides come in different formulations, each having benefits in certain situations. Different active ingredients operate on the insect in different ways. Some pesticides are fast acting while others are slow acting. While it is satisfying to see immediate death, slower acting pesticides allow the active ingredient to be transferred to all of the nest’s residents.
- Dusts – Residual dusts can be very effective at controlling nests found in wall voids and underground nests. However, dusts have slower knock-down effect than sprays.
- Nests in a wall void – When treating a nest in a wall void, you must figure out the boundaries of nest behind the wall. You can often figure out where the nest is by listening carefully at the wall for vespid activity. Once the boundaries of the nest have been determined, holes can be drilled into the wall and an appropriately labeled residual dust can applied. The holes can be plugged with steel wool to prevent the wasps’ escape.
- Outdoor ground nests can be similarly controlled by approaching the nest at night and dusting the entrance.
- Wasp “Freeze” Products – These aerosol products are designed to project a stream of spray 10 to 20 feet and contain highly evaporative substances that “freeze” or stun the vespids. In addition, these products contain Pyrethrin or a pyrethroid to kill the vespids before they recover.
- These products are very handy for “instant control” of small nests or to eliminate guard wasps near the entrances of large nests before other chemical control methods are used.
- Silica Aerogel and Pyrethrins – Silica aerogel is made from sand and work by absorbing the outer waxy coating on the insect’s body. Once this coating is gone, the insects cannot retain water and die of dehydration.
- For wasp control, these products are formulated as an aerosol and combined with pyrethrins that can be applied into an underground nest or a nest in a wall void.
- Other liquid sprays
- These products are faster acting than dusts, but not as fast as the “freezing” aerosols.
- These include most common insecticides. Remember to check the label to verify your treatment location is an approved site.
- The paper outer layer on yellow jacket and hornet nests is designed to shed water, so these products may need to be injected into the nest for complete control.
Once you have gathered your safety supplies and chosen your insecticides, it is time to treat the nest. Always treat the nest in the evening, think about details such as lighting, ladder safety, and bystanders. Do not underestimate the aggressive nature of yellowjackets and hornets.
- Secure the area – During control efforts, stinging insects may attack anyone within several hundred feet. Schedule control efforts when there is the least amount of people in the area (evening or night). Monitor the area after control until all stinging insects are gone from the nest area. Notify any neighbors in the area to stay indoors and turn off porch lights
- For large nests, utilize “distraction techniques” – At night, yellowjackets and other wasps will be attracted to lights.
- Set up bright lights (shop lights or car headlights) about 20 feet away from the nest.
- Set up the lights on the opposite side of the nest that you will be working from.
- Do not stand between the lights and the nest.
- As the angry hornets swarm from the nest, they will be fly towards the light and away from you.
- Wet/Dry Vacuum – During the treatment you can place the nozzle of a shop vacuum near the entrance of the nest. Have a few inches of soapy water in the canister of the vacuum. As yellowjackets swarm out to defend their nest, many will be sucked up by the vacuum, thus reducing their ability to sting you.
- Vacuuming alone will not safely eliminate a large yellowjacket nest. This should be used as an aid during and after a chemical treatment only.
- For large nests with multiple openings, you may need several vacuums set up.
- Use a fast-knockdown “freezing aerosol”. For a large nest, this freezing aerosol will kill the hyper aggressive guard wasps posted at the entrance. For a small paper wasp nest, this may be all you need.
- Use a residual product such as a dust or residual spray to kill the colony.
- Dust will be transferred throughout the nest by the insects ensuring complete control.
- Liquid sprays may need to be injected with an injection wand to penetrate into large yellowjacket or hornet nests.
- Be sure all parts of the nest are thoroughly treated.
- Prevent Reinfestation – Other stinging insects may be attracted to dead nests and may attempt to re-colonize.
- Remove and/or collapse the nest if possible
- Seal all openings that void-nesting yellowjackets or wasps are using.
- Ground nests should be collapsed and filled with sand
- Monitor the area to ensure other colonies do not try to reestablish in the same area.