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.

Adulticides are applied using ultra-low volume (ULV) equipment, which release a very small amount of product—typically less than one ounce per acre. ULV applications may be made by ground or aerial equipment and pose no safety or health threat for humans or animals.

Ground Applications:

Ground applications use truck-mounted or hand-held ULV equipment to apply a fine mist where adult mosquitoes are most active. The application contains a small amount of EPA-approved pyrethrin or pyrethroid active ingredient, typically between ½ and 1½ ounces per acre.

The material is atomized into small droplets and 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. All applications are made with calibrated equipment by state-certified and trained technicians.

Aerial Applications

When large areas require treatment, aerial ULV applications may be used. Aircraft apply a very small amount of product—0.64 oz/acre (pyrethrin) / 0.75 oz/acre (naled)—using specialized equipment that monitors real-time weather conditions to ensure the treatment is accurately applied to the target area.

Aerial applications use EPA-approved products containing one of the following active ingredients:

• Pyrethrin
• Pyrethroid
• Naled (an organophosphate)

Pyrethrins/Pyrethroids:

Pyrethrins are natural insecticides derived from chrysanthemum flowers and disrupt the nervous system of insects by blocking chemical signals at nerve junctions, causing rapid knockdown and paralysis.

Pyrethroids are synthetic versions of pyrethrins that work similarly and are also approved by the U.S. Environmental Protection Agency (EPA) for mosquito control.

Organophophate

Organophosphates, such as Naled, act as an acetylcholinesterase inhibitor, overstimulating the insect's nervous system until it results in paralysis and death.

Rotating between different types of active ingredients helps reduce the development of insecticide resistance in mosquito populations while maintaining effective control.