MOSQUITO CONTROL IN OAK RIDGE

 

The recent incidents across the nation and the South involving the West Nile virus have raised concern by many people with regard to what steps local governments might be taking to control mosquitoes in their areas since mosquitoes are the primary transporters of the virus.

 

There are generally three approaches to controlling mosquitoes.  The first involves the use of EPA approved insecticides containing chemicals such as Permethrin or Resmethrin for fogging and killing the adult, flying mosquitoes.  The second involves the use of approved larvacides to kill mosquito larvae or eggs that may be present in standing water.  The final approach lies in minimizing and eliminating standing water, which is where mosquitoes lay their eggs and larvae form.

 

 

In past years the City of Oak Ridge used fog-spraying equipment to aid in controlling mosquitoes.  The fog spraying was stopped in the late 1980’s due to a general lack of complaints and requests for spraying and the cost of replacing the aged and obsolete fogging equipment.  Presently the City of Oak Ridge has no formal mosquito control program.  Like many other cities we prefer the more cost effective means of public education and advising residents of ways to minimize or prevent growth in the mosquito population, particularly on their own properties. 

 

A survey of several other cities in Tennessee indicate that most do nothing other than to advise residents to check their property every 3 to 4 days to eliminate any standing water, no matter how large or small the amount and to avoid being outdoors in the early morning and evening hours when mosquitoes are at their peak presence.

 

If the City were to decide to initiate a new fogging program it would be necessary to purchase fog spraying equipment and chemicals.  The estimated cost for one unit mountable into a pickup truck is $7500 with a delivery time of 4 to 6 weeks.  The approximate cost for enough chemical to provide one fogging application around the city is $8500.  

 

The fogging works by killing adult mosquitoes on contact.  However, it is very costly at an average of $40 per gallon and has to be repeated every four to five days to be effective when new mosquitoes appear.  Typical fogging applications require approximately eight gallons of chemical per hour.  This equates to a cost of $320 per hour for chemicals plus the cost of labor and equipment.  Staff estimates the cost for one cycle of spraying the residential areas of the City to be approximately $10,000.  Considering that “mosquito season” typically extends from mid-May to mid-September, a fogging program would need to run continuous over that period in order to be of maximum benefit.  The estimated cost of a program of that magnitude would be $260,000. 

 

Mosquito eggs or larvae are eliminated by using approved larvacides placed in bodies of standing water.  The larvacides typically come in granule form and are tossed into the standing water.  At approximately $0.35 per ounce larvacides are also very costly as large quantities are required for treating large areas of water.  Typically, an average of 4.5 ounces are required to treat a 100 square foot area.  This equates to a cost of $650 per acre of water.  The City does not get involved in treating bodies of standing water are they are generally located on private property and are the responsibility of the property owner.

 

TVA attempts to control the mosquito population on its lakes by raising and lowering the lake water levels making it more difficult for the eggs to gather and survive around the water’s edge.

 

It should be noted that the fogging process generally only covers a 100 feet wide area along the right-of-way and does not provide any concentrated coverage into residential back yards, the area most prone for harboring mosquitoes.  Homeowners may choose to purchase portable fogging units and/or apply larvacides to address mosquito problems in their backyards.  A check with local stores shows that portable electric or propane operated fogging units and fogging chemicals, aerosol foggers and mosquito larvicides are available at various local retailers.

 

The overall most cost effective means to avoid exposure to mosquitoes is the elimination of standing bodies of water and avoiding the outdoors in the early morning and evening hours.   Anyone wanting to be outdoors during these hours is encouraged to wear long sleeve shirts and pants and to use an insect repellant containing the chemical N-N-diethy-meta-toluamide or DEET, following the instructions on the label.  Parents are encouraged to check with their child’s doctor prior to applying repellants on their child or children.  

 

Below are some links to various Internet web sites related to mosquito control and the West Nile Virus.  Additionally, brochures with tips for controlling mosquitoes will be available at the Public Library, Municipal Building, and the Central Services Complex.

 

For more information on mosquito control and the West Nile Virus, check out the following web sites:

           

Centers for Disease Control

 

U.S. Environmental Protection Agency

 

 

MOSQUITO CONTROL TIPS