Adult Mosquito Control Information

About

The Vector Control Program (VCP) monitors mosquito-related public health risks throughout the County. If an elevated public health risk exists that cannot be reduced by other means, such as eliminating mosquito breeding or preventing larval growth, then the VCP may use adult mosquito control treatments to reduce the number of infected adult mosquitoes. 

Depending on the situation, these adulticides may be applied with hand-held, backpack, portable, and/or truck mounted equipment by skilled vector control technicians certified by the California Department of Public Health. Larvicides may also be used in situations where mosquito breeding is detected. Every attempt will be made to contact residents in affected areas at least 24 hours prior to treatment.  

Received a notice? Click Here to read online. 


Currently Scheduled Treatments

July 14 and 15, 2025

The Vector Control Program will be treating areas within the Cities of San Diego and La Mesa (outlined in red in the map below) with an adult mosquito control product in order to reduce mosquito numbers and the risk of West Nile virus. Truck mounted treatments will take place July 14 and 15, 2025 between 1am and 6am. 

Vector Control staff will be responding to emails and phone calls over the weekend if you have any questions. Staff will also be available to answer questions at an information session this Saturday, details below. 

Contact information

(858) 694-2888
vector@sdcounty.ca.gov

Information session details:

La Mesa Library
Saturday, July 12 10am-12pm
8074 Allison Avenue
La Mesa, CA 91942


What products will be used?

The product used in our treatments is called AquaDuet. This product has been reviewed and approved by the Environmental Protection Agency for use in mosquito control for public health purposes and poses low risks to people and pests when applied according to the pesticide label. This product will only be applied as indicated by trained and state certified vector control technicians. 

AquaDuet Label

AquaDuet SDS

The adult mosquito treatment will be applied as an ultra-low volume mist which uses a very small amount of pesticide (less than a few ounces per acre). This minimizes the amount of product needed while ensuring effective mosquito control. 


Do I need to take precautions?

Treatment with this product has been evaluated by the Environmental Protection Agency for safety. People, pets, and livestock can be outdoors during the application.

If you are concerned about the treatment, you can stay indoors and close windows during the treatment. Any product will dissipate after about 30 minutes and afterwards you can resume normal activities.

You can also optionally:

  • Turn off any fans that draw air in from the outside. 
  • Keep pets indoors during spraying.
  • Cover your fishponds.
  • Clean homegrown fruits and vegetables with water as you would typically do before cooking or eating

Beekeepers and those with insects kept outdoors are encouraged to shelter hives and habitats during treatments. Hives can be protected by covering them with a wet burlap cloth.


How does the County decide when to treat?

Our team regularly traps mosquitoes and tests them for diseases like West Nile virus, dengue, and Zika. If our analysis of this information shows that there is an elevated risk to public health in a certain area, we will consider using adult mosquito control products. 

This decision making process is described in our Mosquito-borne Virus Strategic Response Plan which is based on State guidelines and peer reviewed research. 

The Vector Control Program uses an integrated vector management approach. Adult mosquito treatments are always accompanied by efforts to find and control sources of mosquito breeding in the neighborhood and to educate the public about mosquito prevention. You can learn more about how the Vector Control Program controls young mosquitoes in standing water here

 

More Frequently Asked Questions


Questions?

For more information on Vector Control please call: (858) 694-2888 or email vector@sdcounty.ca.gov

For public health questions please call Public Health Epidemiology at: (619) 692-8499.