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Seeing a wasp in your yard may make you want to panic. However, wasps are not as bad as they might appear. Before you break out that can of wasp killer, it is important that you know how and when to use it. How to Kill Wasps will help you identify the species of wasp and show you the best way to treat the problem.
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Killing Wasps Tips
- Wasps are beneficial because they prey on agricultural pests.
- Wasp colonies naturally die off in the fall.
- Wasps are less active at night, so night is the best time to spray pesticides.
- Wasps are attracted by light, so cover your flashlight with red cellophane.
- Wear long sleeves and pants, socks, shoes and gloves.
- Never attempt to control wasps if you are allergic to wasp stings.
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Introduction
- Nothing can provoke panic in a person more than a wasp. Not surprising since hundreds die each year after suffering an allergic reaction to the venom contained within the stings of these insects.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets However, a wasp should not be considered evil incarnate nor should it be destroyed needlessly. Before you take any action against wasps, arm yourself with the knowledge about what actions to take and when to take them. Your situation may not be as dire as you imagine.
- The term "wasp" refers to a variety of species that includes paper wasps, hornets, yellowjackets and other wasps. Before you decide what to do, you will need to identify the type of wasps you have.
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When to Do Nothing
- Most people's initial reaction when they see a wasp nest is to figure out how to destroy it. However, it is much better to leave the nest alone whenever possible because wasps are beneficial insects. They feed on insects that are damaging to trees and crops as well as houseflies and blowflies.Washington State University Extension: Yellowjackets and Paper Wasps Here are a couple instances when you should do nothing.
- You discover the nest in the fall.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets
- -Wasp colonies only last one year and naturally die off in the fall. Only a newly produced queen, who leaves the nest in the late summer, survives the winter. They will not reuse old nests.University of Minnesota Extension: Wasp and Bee Control
- The nest is located away from high traffic areas.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets
- -As long as you don't disturb the wasps, the wasps will not bother you.University of Minnesota Extension: Wasp and Bee Control
- You are allergic to wasps.HowToDoThings.com: How to Kill Wasps
- -Be safe and call a pest control company.
General Tips on Controlling Wasps
- Although this page gives specific information on how to deal with the different species of wasps, there are some overall tips that are good to follow no matter which kind you are dealing with.
- Find the nest.University of Missouri Extension: Bees and Wasps
- Identify the species of wasp before deciding how to treat.University of Minnesota Extension: Wasp and Bee Control
- Treatment is best done at night when wasps are less active.University of Minnesota Extension: Wasp and Bee Control University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets
- Do not shine a light directly at the nest. Wasps are attracted by light.
- Wear the right clothes. Long sleeves and pants, socks, shoes and gloves will protect your skin from stings. It's also a good idea to wrap your pants legs so the wasps can't get in.HowToDoThings.com: How to Kill Wasps
- It is best to control wasps in June, while the colony is still small.University of Minnesota Extension: Wasp and Bee Control
- Always read the label on pesticides carefully before using and follow the directions exactly.University of Missouri Extension: Bees and Wasps
- Do not allow children or pets near the treated areas until they are completely dry.University of Missouri Extension: Bees and Wasps
- Never swat a wasp while it is on your skin because this can prompt the wasp to sting.University of Missouri Extension: Bees and Wasps
- Do not seal a wasp nest until you are sure there are no surviving wasps inside.University of Minnesota Extension: Wasp and Bee Control
Paper Wasps
- Paper wasps are about 0.7 to 1.0 inch long.University of Missouri Extension: Bees and Wasps They are slimmer than other wasps with a thin "waist".Colorado State University Extension: Nuisance Wasps and Bees The paper wasp's color varies depending on the species.
- The northern paper wasp (Polistes fuscatus) is reddish-orange to dark brown in color.Ohio State University Extension Fact Sheet: Paper Wasps and Hornets
- Some, such as the European or Dominulus paper wasp (Polistes dominula or dominulus), have black bodies with bright yellow stripes and spots, which makes them look similar to yellowjackets.Ohio State University Extension Fact Sheet: Paper Wasps and Hornets
- Others are a combination of yellow, black, red and brown.
- Paper wasps are more easily distinguished by their nests than their appearance.
- Paper wasps, like hornets and yellowjackets, construct their nests from a mixture of chewed wood and saliva that resembles paper.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets
- Paper wasps typically build open-celled, umbrella-shaped nests under eaves, overhangs and ledges.University of Missouri Extension: Bees and Wasps
- European paper wasps will nest in the cavities in the sides of building as well as metal gutters, poles, outdoor grills and similar items.Colorado State University Extension: Nuisance Wasps and Bees
- Paper wasps will not reuse old nests, but may build nests next to older ones.Washington State University Extension: Yellowjackets and Paper Wasps
- European wasps are more aggressive about defending their nests, but will rarely attack until the threat is inches from its nest.CSU Cooperative Extension: European Paper Wasps
How to Kill Paper Wasps
- Paper wasps are not as aggressive as yellowjackets and hornets and should only be eliminated if they have made their nest in an area where they pose a threat.University of Missouri Extension: Bees and Wasps This can be done either by spraying the nest with a high-pressured stream of water or by using a commercial wasp spray.Texas A&M AgriLife Extension: Paper wasp
- Do not stand directly below the nest because it increases your likelihood of being stung.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets
- Wait at least a day to ensure the colony is dead before scraping or knocking down the nest.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets
- Nests should be removed to prevent problems with carpet beetles, ants and other insects and to prevent other wasps from building a nest there.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets University of Missouri Extension: Bees and Wasps
- Most wasp and hornet aerosol sprays contain pyrethroid, which kills the wasps quickly. Aerosol sprays also have residual activity against wasps to ensure complete elimination of the nest.CSU Cooperative Extension: European Paper Wasps
- If nests are located in voids, treat them by blowing insecticidal dusts unto the holes.CSU Cooperative Extension: European Paper Wasps
- Follow other advice listed in the General Tips on Controlling Wasps section.
Yellowjackets
- Yellowjackets were originally named after their yellow and black striped body markings.University of Missouri Extension: Bees and Wasps Yellowjackets may appear similar to honey bees, but are smaller, brighter colored and lack a hairy body.Colorado State University Extension: Nuisance Wasps and Bees However, not all yellowjackets are yellow and black, just as not all yellow and black wasps are yellowjackets. In the United States, yellowjacket species fall into one of three groups:
- The Genus Dolichovespula group includes aerial yellowjackets (Dolichovespula arenaria) and baldfaced hornets (Dolichovespula maculata).
- The Genus Vespula Rufa group includes southern yellowjackets (Vespula squamosa), California yellowjackets (Vespula sulphurea), prairie yellowjackets (Vespula atropilosa), blackjackets (Vespula consobrina), forest yellowjackets (Vespula acadica), northern red-banded yellowjackets (Vespula rufa), and cuckoo yellowjackets (Vespula austriaca).
- The Genus Vespula Vulgaris group includes western yellowjackets (Vespula pensylvanica), German yellowjackets (Vespula germanica), eastern yellowjackets (Vespula maculifrons), common or Canadian yellowjackets (Vespula vulgaris) and downy yellowjackets (Vespula flavopilosa).
- Wasps in the Vespula Vulgaris group are generally considered pests because they have large nests (numbering in the thousands) and like to scavenge meat and sweets. This means they often hang around anywhere people are dining outdoors, such as stadiums, theme parks and picnic areas. Dolichovespula Yellowjackets and those in the Vespula rufa group are insectivores and are not scavengers. UCR Entomology: Identification Guide for Southern California Yellowjackets
Yellowjacket Nests
- The nests of yellowjackets consist of layers of rounded combs stacked in tiers that are covered with a shell of several layers of pulp.
- Nests are large, about the size of a basketball, and can contain thousands of wasps.University of Missouri Extension: Bees and Wasps
- Nests may be located in old rodent burrows, in crawl spaces, beneath landscape timber, inside walls, in attics, under eves and in trees or shrubs.University of Minnesota Extension: Wasp and Bee Control University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets
- Eastern and Southern yellowjackets usually build their nests underground.University of Missouri Extension: Bees and Wasps
- German yellowjackets usually build their nests above ground.University of Missouri Extension: Bees and Wasps
- Aerial yellowjacket and baldfaced hornets build their nests in trees or on the outside eves of buildings.Washington State University Extension: Yellowjackets and Paper Wasps
- Nest entrances are usually small and inconspicuous.Colorado State University Extension: Nuisance Wasps and Bees
Controlling Yellowjackets
- Because yellowjackets are considered beneficial, nests should be left alone if at all possible. If it is necessary to remove the nest, it should be done very carefully. Yellowjackets are extremely aggressive when their nests are disturbed.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets Wasps will attack once they sense poison near their nests and freeze products are not guaranteed to stop them all.UC IPM: Yellowjackets and Other Social Wasps
- If you decide to treat the nest yourself, here is how to do it:
- Locate the nest during the day, but treat at night.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets
- Spray or pour insecticide directly into nest entrance.
- Plug the entrance with insecticide-soaked cotton, if possible.The Police Notebook: Yellow Jackets
- Wait several days before removing the nest.Washington State University Extension: Yellowjackets and Paper Wasps
- Follow other advice listed in the General Tips on Controlling Wasps section.
- Please note, that even treating after dark and standing well away from the nest, stinging incidents are likely. The entrance of underground nests can be a long way from the nest, and the spray might not be able to reach it. Partially intoxicated wasps are more likely to sting, even if encountered well away from their nest.UC IPM: Yellowjackets and Other Social Wasps
Yellowjacket Traps
- Yellowjacket traps have not shown to be of any value in reducing yellowjackets.NC State University: Controlling Bald-Faced Hornets and Yellowjackets in and around Structures However, if you are interested in making a trap, you can find examples at the following sites:
- University of Missouri Extension: Bees and Wasps
- Washington State University Extension: Yellowjackets and Paper Wasps
Hornets
- There is some confusion over the difference between a yellowjacket and a hornet. Some state that "hornets" refer to a species that build nests above ground and "yellowjackets" refer to a species that builds nests below ground.University of Florida: Yellowjackets and Hornets However, this is not true since many species of yellowjackets will build their nests above ground.
- Scientifically, "true hornets" belong to the genus Vespa while yellowjackets belong to the Vespula and Dolichovespula genera.NC State University: European Hornets Thus the baldface "hornet" (Dolichovespula maculata) is actually a yellowjacket. The only hornet in the United States is the European hornet (Vespa crabro). However, this they often get mislabeled since the baldface hornet is black and white while the European hornet is yellow and dark brown (almost black). While most will state that the baldface hornet is a yellowjacket, some also state that the European hornet is also a yellowjacket.Penn State Entomology Department Fact Sheet: European Hornet
- However, there are some some major differences between yellowjackets and true hornets including:
- Hornets are not as aggressive as yellowjackets.University of Missouri Extension: Bees and Wasps
- Hornets prey on live insects and do not scavenge like yellowjackets.Colorado State University Extension: Nuisance Wasps and Bees
- Hornets typically live in wooded areas and have little contact with humans.Ohio State University Extension Fact Sheet: European Hornet
- Hornets rarely sting unless their colony is disturbed.Colorado State University Extension: Nuisance Wasps and Bees
- Unlike baldfaced hornets, European hornets rarely build nests that are free hanging or in unprotected areas.NC State University: European Hornets Instead, they will build their nests in hollow trees, barns, attics and abandoned bee hives.
- European hornet nests are covered with a brown envelope, while aerial nests of yellowjackets are gray.University of Kentucky Entomology: European Hornet in Kentucky
Controlling Hornets
- As stated earlier, hornets do not bother humans until their nests are disturbed. At which point, they can become extremely aggressive. Since each nest can contain thousands of wasps, this makes removal very difficult and dangerous to control.University of Kentucky Entomology: Controlling Wasps, Hornets, and Yellowjackets However, the same methods listed under Controlling Yellowjackets can be used.
Mud Dauber Wasps
- Mud dauber wasps are solitary wasps that build nests out of mud (hence the name). They are very beneficial because they prey on insects and they rarely sting. Usually, they will only sting if handled roughly or if accidentally trapped.Colorado State University Extension: Nuisance Wasps and Bees Insecticide treatments are not necessary, but unsightly nests can be removed using water and a brush. There is no known method that will discourage mud dauber wasps from building nests in certain areas.Iowa Insect Information Notes: Mud Dauber Wasps
Cicada Killer Wasps
- The cicada killer wasp, or sand hornet, is more likely to scare you than sting you. Its intimidating size of 1-1/2 to 2 inches makes it one of the largest wasps in the United States. However, it is only likely to sting if it is trapped against the skin.Ohio State University Extension Factsheet: Cicada Killer Wasp They build solitary nests in underground burrows.Texas A&M AgriLife Extension: Cicada Killer Because these wasps are beneficial, not aggressive and do not build unsightly nests, control methods are not recommended.Iowa Insect Information Notes: Cicada Killer Wasp and Other Digger Wasps If wasp control is necessary, follow the advice listed in the General Tips on Controlling Wasps section.
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