Comments by Dr. Paul Guillebeau, Professor of Entomology, University of Georgia, Athens
Concerning Automated Misting Systems for Mosquito Control

Public concern about West Nile virus has led to additional risks to human health and the environment. Health concerns have driven sales of automated pesticide misting systems for use in residential areas. These systems make regular, unmonitored applications of pesticides and create many possibilities for unwanted human and environmental exposure. The State FIFRA Issues Research and Evaluation Group in Region 6 addressed this issue in a paper issued in 2004. The situation remains unresolved, but this early draft of the paper will help you understand the concerns.

1) Uncertified Applicators. The misting systems are often marketed and installed by company employees with little or no experience with pesticide application. Because the employees are installing equipment instead of actually applying pesticide, many state pesticide regulations do not cover this activity.

2) Unsubstantiated Claims. Some companies are making improper claims about health protection. West Nile virus can cause health problems for some people; but West Nile virus does not represent health risks comparable to malaria or encephalitis. In this case, the unwarranted application of pesticide may pose a risk greater than the disease.

3) Off Site Drift. The mist units automatically spray pesticide at time intervals. The units deliver pesticide on schedule, regardless of weather conditions. There seem to be no requirements for setbacks from other property. Additionally, the pesticide will be released even if insects are not causing a problem. How would you like to live next to a property where pesticides were released on a schedule even if the wind was blowing into your backyard while your children were playing there?

4) Human Exposure Risks. Remote control units are available, possibly allowing the application to be "controlled" by children or teens "playing" with the system causing potential harm to unsuspecting friends or pets. The pesticides may be sold or provided to the homeowners to "maintain" the system often without appropriate precautions regarding proper mixing, use, or, disposal.

5) Non-target Exposure. Dripping nozzles may be attractive as a water source, particularly during dry weather.

6) Discourages Integrated Pest Management (IPM). An IPM program is the best way to minimize pesticide applications by emphasizing non-chemical alternatives. One of the most important things a person can do to control mosquitoes is to empty sources of water for mosquito breeding or to add an appropriate larvicide to water sources. Many people using this automated system will assume that additional steps are unnecessary.

7) Increased Resistance. The continual, indiscriminate application of a pesticide is one of the best (or is it worst?) ways to select for resistance. Some of the web sites for the mosquito mister program report that insects cannot develop resistance to the active ingredients they recommend. I am not sure what entomology program they attended, but they were not in my classes.

Many state regulators and the American Association of Pesticide Safety Educators (of which I am a proud member) think automated, unmonitored pesticide applications are a bad idea. They are encouraging EPA to prohibit application of pesticides through this system.

If you were thinking of buying an automated system to spray for mosquitoes, please think again. The idea of killing mosquitoes automatically may be appealing, but the associated risks are not.

(Note: Thanks to Walter Reeves for sharing these comments given to him by Dr. Guillebeau)

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