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The 2023 Mosquito Season

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Date: Jul 20 , 2023
Category: News & Announcements

As you have probably noticed, there has been an increase in the number of mosquitoes recently due to a variety of factors, including the warmer weather and high tides.

To better protect our communities and the environment, the Vector Control Program (VCP) applies mosquito larvicide via helicopter to mosquito breeding areas that cannot be treated by hand.  These aerial applications occur every three to four weeks during the mosquito breeding season, generally April to October, or as needed.

The granular larvicides used by the Vector Control Program act specifically on mosquito larvae and will not harm people, pets, plants, or wildlife. The larvicide consists of granules containing Lysinibacillus (Bacillus) sphaericus, Bacillus thuringiensis israelensis, and/or Saccharopolyspora spinosa products.  These naturally occurring bacteria target mosquito larvae and prevent them from developing into biting adults.

2023 Aerial Larvicide Application Schedule

  • April 26
  • May 17 and May 18
  • June 7 and June 8
  • June 28 and June 29
  • July 19 and July 20
  • August 9 and August 10
  • August 30 and August 31
  • September 20 and September 21

Please note, aerial larvicide application dates are subject to change depending on conditions.

If you would like to sign up to receive e-mail notifications of scheduled aerial applications, you can subscribe here. 

If you encounter a mosquito problem in your neighborhood, reach out to the County Vector Control Program:

Protect Yourself & Your Home

Residents should also help protect themselves from mosquitoes in and around their homes by finding and dumping out standing water to keep the pests from breeding. Getting rid of mosquito-breeding sites is critical to lowering the number of mosquitoes in our community. A mosquito only needs a tiny bottle cap-size pool of water to lay up to 300 eggs, which is why removing standing water is critical.

The Basics: 

  • Do not leave standing water in watering cans, empty after each use.
  • Do not let ANY water sit in drip pans under plants. Place sand or fine gravel in the drip pans. Make sure pots are draining well and there are no puddles, even tiny ones can become a breeding ground.
  • Fix any leaky faucets and hoses. Mosquitoes can breed in the water that pools underneath them.
  • Water can collect in cans, bottles, toys, coffee cups, pet bowls, etc. Clear your patio of any potential breeding debris. 
  • Mosquito fish may be picked up free of charge at different locations throughout San Diego County.

Protect yourself from mosquito-borne illnesses by wearing long sleeves and pants or use insect repellent when outdoors. Use insect repellent that contains DEET, picaridin, oil of lemon eucalyptus, or IR3535. Make sure screens on windows and doors are in good condition and secured to keep insects out.

Some useful mosquito (and other vectors) information can be found on the County of San Diego’s vector control website and useful fact sheets on preventing mosquito breeding and protecting against mosquito bites can be found here.