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Mosquitoes




Not all mosquitoes transmit diseases, but they can all be a nuisance. There are many different species of mosquitoes with different preferences for climate and breeding territory. Typically, mosquitoes lay their eggs in standing water. Mosquito larvae hatch from the eggs and remain in the water, feeding on tiny organisms. Once they mature, adult mosquitoes leave the water to breed.

Visit the following pages for additional information about mosquito control:

If you have questions about this, or any pesticide-related topic, please call NPIC at 800-858-7378 (8:00am - 12:00pm PST), or email us at npic@oregonstate.edu.

Last updated May 12, 2025

Mosquitoes

  • Confirm their identity. Are you sure you're dealing with mosquitoes?
  • Wear clothing that covers as much of your body as possible.
  • Stay indoors in the early mornings and evenings when mosquitoes are most active.
  • Install or repair screens on windows and doors.
  • Use mosquito netting to cover beds, baby carriers, porches, tent openings, and other areas.
  • Remove standing water where mosquitoes may breed.
  • Make sure gutters and ditches are draining properly. Empty trash cans, tarps, pop bottles, etc.
  • Dispose of extra tires properly, or puncture them to prevent standing water.
  • Replace water in bird baths every few days. Check fountains for mosquito larvae.
  • Report abandoned pools to your health department.
  • Stock ponds with mosquito eating fish.
  • Mow your lawn often and keep plants low in your yard.
  • Insect repellents have been recommended, if needed. For children, consider these precautions.
  • Find out what your community is doing to manage mosquitoes.
  • If you choose to use a pesticide, read the label before you buy. Try a lower toxicity product first.
  • If you have a pesticide product in mind, have your label handy and click here for information about that product.
These images are graciously allowed to be used by NPIC by Bugwood.org. Images included in the Bugwood Network Image Archives (ForestryImages.org, IPMImages.org, Invasive.org, and InsectImages.org) are made available under a Creative Commons license. Individual photographers retain all rights to images included in the archive.

Keeping Mosquitoes Out of Your Yard

Mosquitoes undergo four life stages: egg, larva, pupa, and adult. Disrupting a mosquitoes' life cycle and habitat may reduce the number of mosquitoes around you and your environment. There are steps you can take to reduce mosquito populations before choosing to use a pesticide product. Get others involved to be even more effective!

Mosquito eggs

Most mosquitoes lay their eggs in water, and they don’t need much. A Frisbee or a plastic bottle cap can hold enough water to support mosquito breeding.

  • Find and remove any puddles of water or standing water around your home to reduce breeding sites.
  • Puncture unusable tires in the yard to prevent pools of water from forming inside them.
  • Wipe out your bird-bath every few days. The eggs can get stuck to the bottom and survive dry periods.
  • Maintain your swimming pool to prevent mosquito breeding, and report abandoned pools to your local health department.
Mosquito larvae
Adult mosquitoes
  • Keep grass and shrubs trimmed short; this will reduce places for flying (adult) mosquitoes to rest.
  • Keep windows and door screens in good working order.
  • Use mosquito netting over infant carriers when outdoors, especially at dusk.
  • Wear long-sleeved shirts and long pants while outdoors, and consider staying indoors early in the morning and evening when mosquitoes are most active.
  • Consider using an electric fan to keep mosquitoes from flying onto you. Mosquitos don't like wind.
  • Consider using pesticide-treated clothing. Make sure to select products with specific instructions for treating clothing.
  • Consider using an insect repellent. NPIC's Insect Repellent Locator can be useful when deciding on insect repellents.
  • Be aware of public health mosquito control programs, they may use insecticides to kill adult mosquitoes. Your local government may lead these efforts.

If you choose to use an insecticide, be sure to read and follow all label directions. Some products are designed to be applied directly to water to control mosquito larvae, while others are used more broadly to control adult mosquitoes. Click on the "Chemical Control" tab for more information.

Additional Resources:

Pesticides Used in Mosquito Control

There are a variety of products available on the market for the public and for professionals when it comes to mosquito control. Larvicides are chemicals designed to be applied directly to water to control mosquito larvae. Adulticides are used in fogging and spraying to control adult mosquitoes. Synergists are not toxic to the mosquitoes themselves, but they make adulticides more effective.

Some communities provide mosquito control as a service to the public and may apply pesticides from trucks or planes. To find out whether or not your community sprays for mosquitoes, try contacting your local health department or mosquito control district.

There are several non-pesticide actions you can take. If you decide to use a pesticide for mosquito control, always read and follow the label instructions carefully. Visit the "What can I do?" tab for more information.

Pesticides for Adult (flying) Mosquitoes

The following list of ingredients is not a recommendation and provides examples only.

Pesticides for Larval Mosquitoes (young mosquitoes in water)

The following list of ingredients is not a recommendation and provides examples only.

Pesticide Synergists

The following list of ingredients are not a recommendation and provide examples only.

Diseases Transmitted by Mosquitoes

Some mosquitoes are vectors for diseases. This means they can transmit diseases from one human or animal to another. Typically, the diseases are caused by viruses or tiny parasites. For example, a mosquito that bites an infected human or animal can pick up a virus along with the blood meal. The mosquito and virus do not harm one another but the virus reproduces inside the mosquito. Later, the mosquito can pass the viruses to other humans when biting them.

If you're planning a trip and wondering how to protect yourself and your family from vector-borne illnesses, visit the Centers for Disease Control's webpage about Preventing Mosquito Bites While Traveling.

Zika Virus

West Nile Virus

Malaria
Dengue Fever
Chikungunya
Dog Heartworm
Other Diseases

Automatic Misting Systems

Automatic misting systems include plumbing around the perimeter of a home or yard, to deliver an insecticide mist at scheduled time intervals. There is no data showing their effectiveness in preventing disease transmission. The U.S. EPA does not expect risks of concern for people if label directions are followed.

The American Mosquito Control Association has several concerns with automatic misting systems, including potential pesticide resistance, non-target impacts to fish and pollinators, and increased risk of human pesticide exposures. If you choose to install a system, keep these tips in mind.

  • Avoid direct contact with sprays by keeping people and animals away from the spray zone. Keep outdoor pets away from the treated area.
  • Avoid touching plants or objects in the treated area.
  • Avoid releasing the mist too frequently. Overuse could cause unacceptable risks.
  • Be vigilant about the maintenance of your misting system.
  • Keep in mind that insecticides are toxic to insects, including bees and other pollinators.
  • Note that many insecticides are toxic to fish and aquatic life, including pyrethrins and pyrethoids.
Additional Resources:

County Extension Offices

Through its county agents, the Cooperative Extension Service gives individuals access to the resources at land-grant universities across the nation. These universities are centers for research in many subjects, including entomology (the study of insects) and agriculture. Each county within the United States has an Extension office, which is staffed with agents who work closely with university-based Extension specialists to deliver answers to your questions about gardening, agriculture, and pest control.



Additional Resources:



NPIC answers common questions asked by the public about pests and pesticides. This information is intended to be educational in nature and helpful to consumers for making informed decisions about pesticide use.

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