Westchester County's Lyme Disease Crisis
Westchester County is one of New York State's most consistently high-risk counties for Lyme disease. The county's combination of dense deer populations, extensive wooded corridors, and residential neighborhoods that border preserved open space creates near-ideal conditions for deer ticks — the tiny arachnids responsible for transmitting Lyme disease and several other tick-borne illnesses.
With nearly 1,000 confirmed Lyme cases reported in Westchester County in a single recent year, this is not a marginal risk. It is a genuine public health concern that warrants serious attention from every homeowner and family in the county.
Why Westchester Has Such High Tick Pressure
Several factors combine to make Westchester County a particularly active Lyme disease zone:
Large deer populations: White-tailed deer are the primary reproductive host for adult deer ticks. Westchester's network of parks, nature preserves, golf courses, and wooded residential areas supports one of the densest deer populations in the New York metro region. More deer means more ticks completing their life cycle and more ticks being deposited throughout residential neighborhoods.
Extensive wooded corridors: The northern and eastern portions of Westchester — Bedford, North Salem, Lewisboro, Somers, and Yorktown — have significant forested areas that support large tick populations. But even the more developed southern county communities of White Plains, Scarsdale, and Bronxville have wooded parks and golf courses where tick pressure is real.
Tick-favorable microhabitats: Deer ticks thrive in the transition zones between grass and woodland, in leaf litter along fence lines and wooded edges, and in dense ground-level vegetation. Many Westchester residential properties have exactly these conditions along their back yards and lot lines.
Five tick-borne diseases: Westchester County health data shows that tick-borne disease surveillance encompasses not just Lyme disease but also anaplasmosis, babesiosis, ehrlichiosis, and Rocky Mountain spotted fever — with Lyme disease accounting for approximately 97% of confirmed vector-borne disease cases.
The Deer Tick Life Cycle and When You're Most at Risk
Understanding the deer tick life cycle helps explain why tick exposure in Westchester County is a true year-round concern, not merely a summer issue.
Nymphal ticks (May–July) are the highest Lyme risk: Nymphal deer ticks are the size of a poppy seed — nearly invisible — and are responsible for the majority of Lyme disease transmission in Westchester County. They are most active from May through July, coinciding with outdoor season, and their tiny size makes them easy to miss during self-checks.
Adult ticks (March–May and October–November): Adult deer ticks are easier to spot — about the size of a sesame seed — but are active on warm days from early spring through late fall. Adult female ticks feed on deer and can deposit hundreds of eggs.
Winter is not safe: Deer ticks can remain active on days when temperatures rise above freezing, meaning there is no reliable "tick-free" season in Westchester County.
Which Westchester Communities Have the Highest Risk?
Tick exposure risk exists throughout Westchester County, but several communities and property types see the heaviest pressure:
Highest risk: Bedford, North Salem, Lewisboro, Somers, Pound Ridge, Yorktown, and Cortlandt — all in the northern tier where forested land is most extensive and deer densities are highest.
Elevated risk: Mount Kisco, Katonah, Pleasantville, Armonk, and Chappaqua — central county communities adjacent to significant preserved land.
Meaningful risk: White Plains, Scarsdale, Harrison, Bronxville, and Larchmont — even southern county communities have park margins, golf courses, and wooded lot lines where tick exposure is real.
Professional Tick Control for Westchester Properties
Professional perimeter tick treatment — targeting the specific microhabitats where ticks concentrate — is the most effective protective measure available to Westchester homeowners. A properly applied perimeter treatment addresses:
- The leaf litter and ground-level vegetation along wooded lot lines
- Low-growing shrubs and ornamental plantings adjacent to lawn areas
- Transition zones between maintained lawn and naturalistic garden areas
- Shaded areas under decks and along fence lines
What You Can Do as a Homeowner
Professional treatment combined with homeowner best practices provides the strongest protection:
- Keep grass mowed short, particularly along wooded edges
- Remove leaf litter from yard margins and against the home's foundation
- Create a 3-foot mulch or gravel barrier between lawn and wooded areas
- Move wood piles and recreational equipment away from yard margins
- Check people and pets thoroughly after any outdoor activity, including your own backyard
- Talk to your veterinarian about tick prevention for dogs and cats
- Know the symptoms of Lyme disease and other tick-borne illnesses