Spotted Lanternfly inSullivan County, NYSPOTTED LANTERNFLY GUIDE
Sullivan County — with Monticello as county seat — entered the SLF watch zone in 2023 as populations advanced westward through the Catskills and northward from New Jersey along the Route 17/I-86 corridor. The county presents a distinctive spread risk profile: Resorts World Catskills casino draws enormous vehicle traffic from the New York and New Jersey metro area, concentrating vehicles from established SLF zones in its large parking areas through the year. The Delaware River corridor along the county's western edge is lined with Tree of Heaven, providing a natural SLF pathway along the upper Delaware. Bethel Woods Center for the Arts — built on the site of the original 1969 Woodstock festival — hosts large-scale events that bring significant regional visitor traffic.
Highest activity zones
SLF Hotspots in Sullivan County, NY
Delaware River corridor
Active zone
Route 17/I-86 freight corridor
Active zone
Resorts World Catskills parking areas (high-risk vehicle concentration)
Active zone
Bethel Woods grounds
Active zone
Bashakill Wildlife Management Area
Active zone
Primary SLF food source
Tree of Heaven in Sullivan County, NY
Tree of Heaven is established along the Delaware River corridor and Route 17/I-86 road margins in Sullivan County, creating SLF dispersal pathways from the established lower Hudson Valley and New Jersey infestation zones into the upper Catskills. The Resorts World Catskills parking areas and access roads are a priority monitoring zone — vehicle traffic from heavily infested metro areas concentrates here continuously. Bethel Woods grounds and the Bashakill Wildlife Management Area margins have additional ToH populations that require active monitoring as SLF populations continue to advance into this watch-zone county.
Identify Tree of Heaven →Local action resources
What To Do in Sullivan County, NY
Report a Sighting
Every sighting in Sullivan County, NY maps the invasion front. Report directly to NY Department of Agriculture & Markets.
Report Now →Squish on Sight
See a spotted lanternfly? Kill it immediately — it is legal and encouraged in all states. Learn the best kill methods.
Full Fight Guide →Map ToH in Your Block
Tree of Heaven removal cuts off SLF food supply. Add ToH sightings to the community map to guide removal efforts.
View Sighting Map →Statewide resources
Full NY State Guide
County-level data, quarantine zones, treatment guides, and agency resources for the entire state.
See the full NY guide →Community intelligence
Live Sighting Map
See where SLF has been spotted near you in Sullivan County, NY. Add your own sighting to help map the front.
Open the Map →Free weekly fight briefing
Fight SLF in Sullivan County, NY.
One email per week. Your zip code. Your threat level. Your action plan. Know exactly what to do this week in Sullivan County, NY.