FAQ: Mosquito Control
What are "larvicides" and "adulticides"?
Larvicides are products used to kill immature mosquitoes before they become adults. They can be either biological (such as toxin from specific bacteria that is lethal to mosquito larvae but not to other organisms) or chemical products, such as insect growth regulators, surface films, or organophosphates. Larvicides are applied directly to water sources that hold mosquito eggs, larvae or pupae. When used well, larvicides can help to reduce the overall mosquito burden by limiting the number of new mosquitoes that are produced.
Adulticides are products used to kill adult mosquitoes. Adulticides can be applied from hand-held sprayers, truck-mounted sprayers or using airplanes. Adulticides, when used well, can have an immediate impact to reduce the number of adult mosquitoes in an area, with the goal of reducing the number of infected mosquitoes that can bite people and possibly transmit West Nile virus.
Both larvicides and adulticides are regulated by the US Environmental Protection Agency.
What is CDC's position regarding the use of chemical mosquito control?
Chemical control measures are one part of a comprehensive and integrated mosquito management program. An integrated program is the most effective way to prevent and control mosquito-borne disease. An integrated mosquito management program should include several components:
- surveillance (monitoring levels of mosquito activity, and where virus transmission is occurring),
- reduction of mosquito breeding sites,
- use of pesticides and biological methods to control both mosquito larvae and adult mosquitoes as indicated by surveillance results, and
- community outreach and public education.
Control measures, including the decision to use chemical adulticides (pesticides to kill adult mosquitoes) should be based on surveillance data and the risk of human disease. CDC's Revised Guidelines for Surveillance, Prevention, and Control of West Nile Virus in the US, 2013 [PDF - 69 pages] provides detailed guidance about the use of control measures, including suggestions for a phased response and the actions that are possible at different levels of virus activity.
How are mosquitoes controlled during outbreaks?
The CDC recommends that control measures, including the decision to use chemical adulticides (pesticides to kill adult mosquitoes) should be based on surveillance data and the risk of human disease. CDC's West Nile Virus in the United States: Guidelines for Surveillance, Prevention, and Control, updated for the first time since 2003, incorporates the most up-to-date understanding of how West Nile virus spreads between mosquitoes, birds, and people. The guidelines feature the development of procedures to protect people from West Nile virus including suggestions for a phased response and the actions that are possible at different levels of virus activity.
Are pesticides harmful to people?
Effect on human health is one of the primary factors considered in regulation of pesticides. Pesticides that can be used for mosquito control have been judged by the EPA not to pose an unreasonable risk to human health. People who are concerned about exposure to a pesticide, such as those with chemical sensitivity or breathing conditions such as asthma can reduce their potential for exposure by staying indoors during the application period (typically nighttime).
A published study, (MMWR, July 11, 2003) examined illnesses in nine states associated with exposure to pesticides used to control mosquito populations from 1999-2002. This study found that "application of certain insecticides poses a low risk for acute, temporary health effects among person in areas that were sprayed and among workers handling and applying insecticides.
For more information on pesticides and health, consult the US Environmental Protection Agency which oversees the registration of these chemicals. The National Pesticide Information Center (NPIC) can also provide information through a toll-free number, 1-800-858-7378.
What should I do if I think that I am having health problems because of pesticides used in my area?
If you are experiencing health problems for any reason it is important to see your health care provider promptly. If you are experiencing severe health problems go immediately to an Emergency Room.
How does pesticide spraying affect the environment?
A great deal of research must be done before pesticides can be used in the environment. The best source for finding out about the pesticides used in your area, and their effect on specific types of wildlife, is with the US Environmental Protection Agency, which oversees the registration of these products. The National Pesticide Information Center (NPIC) can also provide information through a toll-free number, 1-800-858-7378.
What training is required for workers who apply pesticides?
Each state has mandated training and experience requirements that must be met before an individual can commercially apply pesticides. In New York state, for example, certified pesticide apprentices must be at least 16 years of age, have completed an 8-hour core training course on safety issues and the use of pesticides, and have at least 40 hours of pesticide use experience in the field under the direct supervision of a certified pesticide applicator. In most states, continuing education hours must be completed to retain applicator licenses. In addition, these applicators must follow the instructions and precautions that are printed on the pesticide label. All pesticide products are required to have a label which provides information, including instructions on how to apply the pesticide and precautions to be taken to prevent health and environmental effects. All labels are required to be approved by U.S. Environmental Protection Agency.
Where can I get information regarding the safety of specific pesticides?
Questions concerning specific pesticides can be directed to the U.S. Environmental Protection Agency, as this agency has responsibility for registration of pesticides. Many issues are addressed on the EPA's Mosquito Control Web site.
The National Pesticide Information Center (NPIC) provides pesticide information and questions about the impact of pesticide use on human health. NPIC is cooperatively sponsored by Oregon State University and the U.S. Environmental Protection Agency. NPIC can be reached toll-free: 1-800-858-7378.
How can I find out what types of pesticides are being used in my area?
Your local mosquito control program can give information about the type of products being used in an area. Mosquito control activities are most often handled at the local level, such as through county or city government. Check with your health department or in the "blue" (government) pages of the phone book for the contacts in your area.
Another resource to learn more about mosquito control is the American Mosquito Control Association.