Polk County Mosquito Spray Program
Spraying within the unincorporated areas of Polk County for adult mosquito control will begin for the 2009 season as conditions warrant.
Areas are treated once per week, weather permitting.
The areas treated on Monday and Wednesday are found highlighted in yellow on the following maps:
Webster Township
Crocker
Saylor
Sheldahl
Jefferson Township
Jefferson Township
Alleman
The areas treated on Tuesday and Thursday are found highlighted in yellow on the following maps:
Douglas Township
Delaware Township
Clay/Beaver
Fourmile Township
Allen/Carlisle
Elkhart
This schedule may change due to weather conditions.
For many years, Polk County has operated a mosquito control program, on a seasonal basis, in an effort to reduce the threat to public health and annoyance from mosquitoes. In addition to ordinance enforcement activities directed at breeding site reduction, our program consists of two primary components: the visual inspection and treatment of standing water areas within the unincorporated areas of the County that have the potential to breed mosquitoes, and a spraying program designed to reduce the numbers of adult mosquitoes in residential neighborhoods.
The following information has been compiled in an effort to provide a general description of our adult mosquito control program.
- The product that we are currently using for adult mosquito control is called Bio-Mist 4+4. The active ingredient in this material is Permethrin. It is a pyrethroid insecticide. Pyrethroids are synthetic versions of a natural insecticide produced by chrysanthemum flowers. Bio-Mist is registered with the United States EPA for control of adult mosquitoes in urban and residential areas. Products containing pyrethroids are widely available for home use on houseplants and in gardens.
- The material is applied according to label specifications. We are currently applying at a rate of approximately 2.16 oz of active ingredient per mile.
- Bio-Mist is a "contact" insecticide, only those mosquitoes that come in direct contact with the mist will be killed. There is no residual control associated with this product since it dissipates from the environment within hours of application.
- Application is via two Ultra Low Volume (ULV) cold aerosol foggers mounted on pickup trucks. Our driver/applicators are certified and licensed with the State of Iowa Department of Agriculture.
- Depending on seasonal weather conditions, we will typically begin spraying in late May or early June. We generally spray Tuesday through Friday nights during the late evening (after 8:00 p.m.) when weather conditions are favorable, pedestrian traffic is at a minimum, and mosquitoes are most active. We spray primarily during periods when adult mosquito populations are very high, or when there is an elevated risk of mosquito borne disease transmission to the general public.
- Areas of the County are generally sprayed twice per week during the peak season and once per week when mosquito counts are down. Spraying is halted during times of high winds, heavy rainfall, or temperature extremes that would render the treatment ineffective. During periods of the summer when mosquito populations are low, spraying will usually be reduced or discontinued until conditions once again warrant resumption.
- Since Bio-Mist is applied at very low concentrations, most people would not be expected to experience any adverse effects from exposure to the spray. Nevertheless, Bio-Mist is a pesticide. Certain individuals may object to or be particularly sensitive to even the very low levels of material that we apply. For this reason, Polk County offers a “shut off” option for those citizens who do not wish to be exposed to the spray.
- If you wish to be added to the “shut off” list, please call 286-2267 during regular business hours with your name and address.
- People on the "shut off" list will hear the truck pass by their home on the list. In these instances, the engine on the sprayer will continue to run; the spray is turned off from the cab at least one hundred feet in either direction from the address of the request.
- For additional information regarding the County’s mosquito control program, product information, or current anticipated spray schedule, feel free to phone 286-2267 between the hours of 8:00 a.m. and 5:00 p.m. Monday through Friday.
Personal Mosquito Control and Protection:
- Do the best you can to eliminate standing water. Buckets, toys, discarded tires, plugged gutters and many other items that hold stagnant water can provide ideal conditions for mosquitoes to reproduce.
- Use a mosquito repellant containing DEET.
- Avoid being outside during the evening hours when mosquitoes are the most active.
- Mosquitoes carry diseases such as Encephalitis and West Nile Virus. They should be taken seriously.