Chemical / Microbial Control

Chemical or Microbial control involves the use of products registered for the elimination of mosquitoes. Chemical and microbial controls are necessary when surveillance indicates biological and physical control methods are unable to maintain mosquito populations at a tolerable level or prevent the spread of disease.

All products used at TMAD are registered with the California Environmental Protection Agency and are listed as public health pesticides. There are two categories of products we use to control mosquitoes:

• Larvacides:Larvacides are used to eliminate immature mosquitoes known as larva. The district operators spend a large portion of their time monitoring sources for larva. The larvacides are an important tool for the operators to help prevent larva from developing into widespread adults.
  More information about larva treaments.

• Adulticides:Adulticides are used to reduce adult mosquito populations when those populations become excessive or there is a threat of mosquito-transmitted virus. Adulticides are applied using an Ultra-Low volume (ULV) application, which typically uses 1 to 2 ounces of a material per acre. The material is atomized into small droplets and broadcast in a fog, which can be effective up to 300 feet away with ground applications.
  More information about adult treatments.