LarvicideWhat is West Nile Virus? West Nile Virus is a disease carried by mosquitoes. It can cause serious illness in humans and may even be fatal.

People only get West Nile Virus when they’re bitten by a mosquito that has bitten an infected bird. To protect our community we are asking residents to help reduce the mosquito population.

Here are some things you can do:

  • Remove from around your home and neighborhood anything that might hold standing water. For example: old tires, buckets and wheelbarrows.
  • Report any standing water that you cannot remove by calling (914) 813-5000.
  • Protect yourself from mosquito bites. 

Here's what we are doing:

The health department's West Nile virus control efforts are focused on adult mosquito surveillance, larval mosquito control and public education.

During the spring and summer months, health department staff trap adult mosquitoes in various locations throughout Westchester. The mosquitoes collected in the traps are submitted for laboratory testing to determine the presence of those that carry West Nile Virus in the county.

Throughout May and June, field inspectors from the Health Department evaluate nearly 60,000 state and municipal catch basins that have the potential to serve as mosquito breeding grounds. All catch basins with the ability to collect standing water are then treated with larvicide to prevent immature mosquito larvae from developing into adult mosquitoes that can spread West Nile virus.

In early May, the health department gives out free fathead minnows to residents to help prevent their ornamental ponds from becoming breeding sites for mosquitoes that can carry West Nile Virus. The minnows reduce the mosquito population because they feed on mosquito larvae and pupae before they emerge into adult mosquitoes.

Dead birds

The United States Department of Agriculture and the Westchester County Health Department are no longer taking reports of dead birds or submitting birds for West Nile virus testing.

If you find a dead bird, please dispose of it properly. To dispose of a dead bird:

  • Use gloves and a double layer of plastic trash bags to pick up the bird.
  • Using your gloved hands and a doubled trash bag, enclose the dead bird in the bags.
  • Close and tie the bags and dispose in the trash or as directed by your municipality.
  • Wash your hands with soap and warm water.

West Nile virus is not transmissible via touching a dead bird. A person must be bitten by an infected mosquito for transmission to occur. If you have any questions please contact the Westchester County Health Department at (914) 813-5000.

West Nile Virus Positive Mosquito Batches 2014


Number of Positive
Mosquito Batches


New Rochelle 1 7/24/14
 Mt. Vernon 2 7/30/14
 Mt. Vernon  1  8/05/14
New Rochelle  1  8/05/14
Yonkers 1 8/29/14

Total # of positive
batches to date


West Nile Virus Data Brief

Insect repellent safety

Maps and charts of West Nile Virus activity

Protecting your pets from West Nile Virus

mosquitolifecycle235Life cycle of the mosquito
The mosquito goes through four distinct stages during its life cycle: egg, larva, pupa and adult. Learn more about the life cycle of the mosquito.

West Nile Virus Resources