Village Prepares for 2021 Mosquito Season

With the warmer weather approaching, the Village of Mamaroneck is actively monitoring for mosquito activity as part of our Village’s mosquito control program. Since 2019, the Village has been using Bacillus thuringiensis subspecies israelensis (Bti), a naturally occurring bacterium found in soils, in order to treat the Village’s catch basins and the marshes in the Shore Acres neighborhood*. Bti is an effective tool that reduces the mosquito population while minimizing the amount of pesticide materials being sprayed or “fogged” into the air.

Should Westchester County inform the Village of a West Nile Virus (WNV) outbreak or other mosquito borne disease, then the Village will need to augment the Bti program by spraying a mosquito adulticide. The product used in the past is Anvil 2+2. We may also use Merus 3.0. These products will only be used as a last resort should a WNV-type outbreak happen.

Located in the Village of Mamaroneck, Otter Creek Preserve (above) is a vibrant mix of coastal waters, marsh and wooded wetlands — all prime mosquito breeding grounds where Bti is applied.

What the Village is doing:

Throughout the spring, staff from the Village's Department of Public Works (DPW) have been cleaning Village catch basins of leaves and debris. In our marshlands  — such as Otter Creek Preserve — 2-5 pounds per acre (or 3/4 oz. to 2 oz. per 1000 square feet) of Bti have been applied. Beginning in the last week of June and ending in the last week of August, the Village monitors its marshes and catch basins multiple times per week in order to keep regular statistical data on mosquitos and will adjust its application of Bti as necessary. These efforts avoid the use of synthetic pesticide materials. While the Village will do everything it can to safely and effectively address the mosquito population, residents can also take an active part in mosquito control by un-clogging rain gutters or dumping standing water (such as from a birdbath) after it rains.

What residents can do:

The Village of Mamaroneck's Committee for the Environment has put together the following resources on "Mosquito Dunks" — a safe, natural and effective mosquito control larvicide that residents can use to control the mosquito population:

• Mosquito Dunks Kill Mosquito Larvae in Standing Water
• Mosquito Dunks Frequently Asked Questions (FAQs)
• Guidance When Using Mosquito Dunks from the New York State Department of Health

We also encourage visiting the Larchmont-Mamaroneck Healthy Yards webpage and scrolling to the section entitled “Mitigating mosquitos without spraying”.

If you must spray pesticides:

The Village of Mamaroneck believes that "in any mosquito control program, pesticide spraying is and should be a last resort." That having been said, we want to take this opportunity to remind residents about Westchester County's Neighbor Notification Law, Chapter 691 of the Laws of Westchester County, which provides that notification is required when pesticides are sold, applied or sprayed.

• Commercial Pesticide Applicators are required to notify property owners of pesticide application to property abutting them 48 hours in advance of application.
• Property Owners are required to inform the occupants of dwellings that abut the property being treated with pesticides 24 hours in advance of application.
• Homeowners are required to post visual notification markers (signs) prior to applying pesticides to more than 100 sq. ft. of their property.

Printable versions of visual notification markers (lawn signs) and retail information signs are available in pdf format. The signs must be printed on brightly colored paper and text may not be changed. Please see the Neighbor Notification Law for posting requirements.

More resources:

Finally, for more information from Westchester County, visit or download:

• Westchester County Department of Health’s West Nile Virus Webpage
• Westchester County Department of Health’s Bug Off Brochure

As more information becomes available, we will update this webpage with additional tips and resources. By taking early, pro-active steps now — when the weather is cooler and drier — we all can help to safely and effectively address the mosquito population in the Village of Mamaroneck.

*On Friday, May 14, 2021, the Village of Mamaroneck mailed the annual “Pesticide Spraying Notification to Reduce Mosquito Activity in Shore Acres” letter to residents in the Shore Acres neighborhood. To download a copy of this letter, click here.