Physical control involves the elimination or reduction of mosquito breeding sites to reduce the opportunities for mosquitoes to develop. When this strategy is effective, it reduces the need for other methods of control and often provides a long term solution.

There are basically three levels of physical control:

• Source elimination: This approach completely eliminates potential habitats for mosquitoes. Source elimination can be as simple as repairing leaky faucets, cleaning out gutters, maintaining swimming pools and filling areas that pond or puddle.

• Source reduction: This strategy involves altering habitats available for mosquito development. Water may not be totally eliminated, but it is greatly reduced or the time the water is left standing is greatly reduced. By reducing the larval habitat, the opportunities for adult mosquitoes to develop and spread disease is decreased. Examples of source reduction include: eliminating vegetation along ditches or building water holding ponds with steep sides.

• Source maintenance: Maintaining a source may be necessary when it cannot be eliminated or altered to reduce mosquito breeding. Source maintenance can include water management, vegetation management, wetland infrastructure maintenance, and wetland restoration. Source maintenance require frequent monitoring for mosquito breeding along with plans for managing mosquitoes at each maintained site.