Spotted Lanternfly inMercer County, NJSPOTTED LANTERNFLY GUIDE
Mercer County — home to Trenton (New Jersey's state capital) and Princeton University — confirmed SLF in 2021 as populations expanded across central New Jersey. The Delaware & Raritan Canal State Park has emerged as a critical SLF corridor, with Tree of Heaven lining much of the historic canal towpath creating ideal conditions for rapid spread. Princeton University campus trees and borough parks are affected, and the Delaware River corridor provides ongoing pressure from neighboring Pennsylvania populations.
Highest activity zones
SLF Hotspots in Mercer County, NJ
D&R Canal State Park trail
Active zone
Princeton borough parks
Active zone
Mercer County Park
Active zone
Delaware River waterfront corridor
Active zone
Trenton rail yards area
Active zone
Primary SLF food source
Tree of Heaven in Mercer County, NJ
The D&R Canal State Park in Mercer County is a textbook SLF corridor — Tree of Heaven lines the historic canal towpath for miles, creating a continuous Ailanthus highway from the Delaware River inland. Princeton borough park margins and the Trenton rail corridor have additional ToH concentrations that support large SLF populations through the summer and fall.
Identify Tree of Heaven →Local action resources
What To Do in Mercer County, NJ
Report a Sighting
Every sighting in Mercer County, NJ maps the invasion front. Report directly to NJ Department of Agriculture.
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 NJ State Guide
County-level data, quarantine zones, treatment guides, and agency resources for the entire state.
See the full NJ guide →Community intelligence
Live Sighting Map
See where SLF has been spotted near you in Mercer County, NJ. Add your own sighting to help map the front.
Open the Map →Free weekly fight briefing
Fight SLF in Mercer County, NJ.
One email per week. Your zip code. Your threat level. Your action plan. Know exactly what to do this week in Mercer County, NJ.