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Adult Treatments

Turlock Mosquito Abatement District‘s primary mission is to protect public health and welfare by managing mosquito populations so they do not present a significant risk to our community. When adult mosquito populations and/or risk of disease transmission exceeds thresholds, then adulticide applications may become necessary. The application method used to control adult mosquitoes is known as ultra-low volume (ULV) due to the small amount of chemical applied (< 1 ounce per acre). ULV applications may be conducted by ground or air equipment.

Ground Applications:

A small quantity of active ingredient pyrethrin or pyrethroid (between 1/2 to 1 1/2 ounces per acre) is atomized into small droplets and broadcast in a fog aimed at where the adult mosquitoes are active. Adulticide applications that are made using truck-mounted ULV equipment can be effective up to 300 feet away. When necessary, ground applications may also be conducted using hand-held sprayers. Applications are made with calibrated equipment used by technicians who are state certified and trained.


The most common materials used for ground ULV applications are classified as pyrethrins/pyrethroids. The District uses Environmental Protection Agency (EPA) approved pyrethrins. Pyrethrins are a naturally occurring substance harvested from chrysanthemums and degrade within 4 to 6 hours after spraying. Pyrethroids are a synthetic form of pyrethrins, and are also commonly used.

Aerial Applications

Aerial applications also utilize ULV equipment which apply a small amount of an organophosphate called naled ( .8 Oz per acre). The airplanes are equipped with technology to allow them to assess real-time meteorological data to optimize the application and to ensure that the application only effects mosquitoes within the targeted area.

Naled Aerial applications are made using EPA approved products called Trumpet EC or Dibrom both containing the active ingredient naled (organophosphate). Organophosphates are synthetic, organic pesticides that contain carbon, hydrogen and phosphorus and act by inhibiting the enzyme cholinesterase in insects. Organophosphates have a different mode of action then pyrethrins/pyrethroids and rotating use of these chemicals allows us to control resistance in the mosquito populations.

For more information on aerial applications please click here: Aerial Adulticiding