Swimming pools & mosquitoes

Swimming pools that are not properly maintained can be excellent larval habitat for mosquito species that can transmit West Nile Virus such as Culex. If you have a swimming pool in your yard that will not be opened, please call our office and we can apply bacterial products that will reduce/eliminate mosquitoes from emerging from this area. These products will not harm your pool if you plan to open it in the future.

If there is a pool in your area that is not on your property, please call your Board of Health office and ask them to e-mail us at cmmcp@cmmcp.org or fax this information on letterhead to (508) 393-8492.

Click here for a 10 second YouTube video of Culex larvae we recently found in an abandoned swimming pool: https://www.youtube.com/watch?v=jehak_hyRT8





Tens of thousands of larvae (identified by our lab as Culex pipiens/restuans) in an abandoned swimming pool. This pool had a 2-3 inch ring around the entire perimeter…this pool was approximately 25 feet across. The circumference is approximately 78.5 feet (c=d*π) – that’s a lot of larvae!!




  • Culex pipiens - Very common year round mosquito which primarily feeds on birds. It will readily enter a house, but is considered shy. It will typically only bite people when they are motionless, usually while they are sleeping. The larvae are found in water holding containers and in polluted waters. Culex pipiens are considered the primary vector of West Nile Virus. West Nile Virus has been isolated from this species in Massachusetts.
  • Culex restuans - Culex restuans has a distribution that ranges from central Canada south into Mexico. The mosquito is very common in the eastern and central United States. Culex restuans undergoes a life cycle that is typical for domestic Culex. Inseminated adult females enter hibernation in fall and pass the winter in a period of quiescence. Culex restuans utilizes an exceptionally wide range of larval habitats. The water used by this species can vary from nearly clear to grossly polluted. Culex restuans regularly colonizes temporary ground pools that remain flooded after they have produced broods of floodwater Ochlerotatus. Culex restuans is also the first species to utilize water that collects in discarded tires. The species can often be found in tire water that is absolutely clear and devoid of leaf litter.