NYC Health Department to Conduct First Aerial Larviciding of the Mosquito Season to Marshes and Other Nonresidential Areas Across New York City
Aerial Larviciding Reduces Number of Mosquitoes and Minimizes Risk of Mosquito-Borne Disease
Health Department Applies EPA-Approved Pesticide to Mosquito Breeding Grounds Throughout the Season
May 30, 2025 — To reduce mosquito activity and the risk of West Nile virus, the New York City Health Department (NYC Health Department) will conduct its first aerial larviciding treatment of the season to marshes and wetland areas of the Bronx, Brooklyn, Queens, and Staten Island on Monday, June 2, Tuesday, June 3, and Wednesday, June 4, 2025, between the hours of 6:00 a.m. and 7:00 p.m., weather permitting. The helicopter will treat only nonresidential areas. In case of bad weather, application will be delayed until Thursday, June 5, Friday, June 6, 2025, and Monday, June 9, 2025 during the same hours, weather permitting.
“As summer approaches, many of us will be swarmed by mosquitos as we spend more time outdoors,” said Acting Health Commissioner Dr. Michelle Morse. “While most mosquitoes across the city do not carry disease, it is still essential to keep New Yorkers safe from any mosquito-borne illnesses. Throughout the summer, the Health Department will be conducting mosquito control events so New Yorkers can enjoy their time outdoors.”
Mosquitoes are mainly active in New York City in April through October. The NYC Health Department monitors mosquitoes that carry the West Nile virus. To date, no human cases of West Nile virus have been reported this season. During warm weather, mosquitoes can breed in any still water that has been standing for more than five days. In the targeted areas, existing hot and wet weather conditions can cause a rise in mosquito populations. Due to size and limited accessibility, these areas will be treated using a low-flying helicopter.
For the aerial application in marshes and wetland areas of the Bronx, Brooklyn, Queens, and Staten Island, the Health Department will use larvicides to kill young mosquitoes before they grow into adults. VectoBac® GS contain naturally occurring bacteria and will be used for this application. These products have been approved by the U.S. Environmental Protection Agency and the New York State Department of Environmental Conservation and will be used on mosquito breeding grounds throughout the mosquito season.
The most effective way to control mosquitoes is to eliminate any standing water. New Yorkers are encouraged to mosquito-proof their homes and take precautions when spending time outdoors.
Reducing exposure to mosquitoes
- Use an approved insect repellent containing DEET, picaridin, oil of lemon eucalyptus (not for children under three), or products that contain the active ingredient IR3535.
- Make sure windows have screens. Repair or replace screens that have tears or holes.
- Eliminate any standing water from your property and dispose of containers that can collect water. Maintaining standing water is a violation of the New York City Health Code.
- Make sure roof gutters are clean and draining properly.
- Clean and chlorinate swimming pools, outdoor saunas and hot tubs. Keep them empty or covered if not in use. Drain water that collects in pool covers.
- Wear lightweight and light-colored long pants and shirts when in marshy areas as possible.
Report standing water by calling 311 or visiting nyc.gov/health/wnv. For more information about West Nile virus, call 311 or visit nyc.gov.
Map of Aerial Larviciding Areas
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MEDIA CONTACT: PressOffice@health.nyc.gov