Misting Systems for Mosquitoes
What You Need to Know About Misting Systems
Misting systems automatically spray insecticides to control mosquitoes around homes and buildings. Homeowners can purchase these systems or install their own systems. Misting systems spray insecticides at timed intervals from a series of nozzles installed along the eaves of a house, fencing, or around landscaped areas.
Misting systems are used to spray U.S. Environmental Protection Agency (EPA) registered insecticides, such as natural pyrethrins and synthetic pyrethroids. Minimum risk insecticidesexternal icon can also be used in misting systems. However, minimum risk insecticides do not require registration with the EPA and have not been evaluated for effectiveness.
Importance of Using an Integrated Mosquito Management Approach
An integrated mosquito management (IMM) approach uses a combination of methods to prevent and control mosquitoes. These methods include conducting mosquito surveillance, removing places where mosquitoes lay eggs, controlling larvae and pupae, killing adult mosquitoes, and monitoring control programs to ensure that mosquito control activities are working. When insecticides are used as part of an IMM approach, communities can be confident that local governments and mosquito control programs are applying insecticides only when necessary.
When mosquito surveillance activities show that adult mosquito populations are increasing or spreading viruses, such as West Nile, professionals may decide to apply insecticides to control mosquitoes. However, misting systems are not a method used by community-based mosquito control programs. Misting systems do not rely on surveillance data and are set to spray insecticide at timed intervals. Therefore, these systems may operate when mosquitoes are not present.
Concerns About Routine Application of Insecticides
CDC does not recommend use of misting systems by homeowners or in residential areas.
Using misting systems to routinely apply insecticides can lead to undesired effects.
- Potential harm to beneficial insects: Misting systems apply insecticides day and night, based on how the user programs the system. Bees, butterflies, and other pollinators may be harmed because misting systems spray insecticides when the insects are active. Local mosquito control programs only apply insecticides when beneficial insects are not active, for example, early morning or late evening.
- Harm to the environment: Misting systems are not regulated by the EPA. Routine spraying can lead to inappropriate application of insecticides, which can negatively impact the environment.
- Increased risk of exposure to insecticides: Misting systems may not have safety mechanisms to prevent direct contact with insecticides. For example, a neighbor, landscaper, or children may be unaware of when the system will release insecticide, and people and pets could be exposed unintentionally. The label on some pyrethrin products includes the word “Caution” because the insecticide may be harmful if inhaled. In addition, the mist can coat outdoor furniture and children’s toys if the system is not properly maintained and calibrated. This can cause additional unintentional exposure to insecticides.
- Insecticide resistance in mosquitoes: Mosquito control professionals monitor mosquito species and numbers to determine when and where to apply insecticides. Over time and repeated use, insecticide resistance can occur in mosquito populations. Insecticide resistance is an overall reduction in the ability of an insecticide to kill mosquitoes. This means that, when used as directed, a product no longer works, or only partially works. To delay or prevent insecticide resistance in mosquitoes, IMM programs monitor for resistance. Users of misting systems cannot monitor mosquitoes for insecticide resistance. Only professionals can do this.
- No data on effectiveness from local governments or mosquito control professionals: Local governments and mosquito control professionals do not evaluate or collect data on the effectiveness of misting systems. The use of misting systems is not consistent with sound IMM practices.