Microbial and chemical control is the use of specific compounds that eliminate immature mosquitoes developing in the water and adult mosquitoes. They are applied when other methods are unable to maintain mosquito numbers below a level that is considered tolerable or when emergency control measures are needed to rapidly disrupt or end the transmission of disease to humans. Larvicides target mosquito larvae and pupae in the water. Adulticides are insecticides that reduce adult mosquito populations.

All products applied by the District are registered with the California Environmental Protection Agency. Our primary goal is to protect public health and welfare by managing mosquito populations so they do not present a significant risk to our community. In the event that mosquitoes do pose a significant threat, we will respond by implementing our Mosquito and Mosquito-borne Disease Management Plan. As part of this plan, we may administer Ultra Low Volume (ULV) treatments by using backpack foggers, hand sprayers, truck-mounted foggers or aircraft, in and around areas where virus activity has been detected. Each fogging unit  is calibrated to ensure the correct amount of product is applied for each treatment area.

To see videos of our staff at work controlling mosquitoes, click the links below.

  • 2021 Catch Basin Program Video
  • 2021 North Sacramento Control Operations Video

    For additional information on products we use please email info@fightthebite.net  or visit the Spraying Updates page

    Notice of Intent to Apply Public Health Pesticides for Vector Control Purposes to Surface Waters and Waters of the US

    Notice of Intent Statewide NPDES Permit


    We will make every attempt to notify individuals who sign up for the District’s notification list via e-mail of specific treatments. However, we may not be able to notify residents if immediate applications are needed to protect public health from diseases. We may also cancel a scheduled operation due to weather and/or other reasons.