Spotted Lanternfly inMontgomery County, PASPOTTED LANTERNFLY GUIDE
Montgomery County is immediately adjacent to Philadelphia and was among the earliest Pennsylvania suburban counties confirmed for SLF in 2018. As a major commuter county, its dense SEPTA rail network and the Schuylkill River corridor have driven rapid SLF spread across the Main Line and into the northern townships. Valley Forge National Historical Park — with significant Tree of Heaven along the Schuylkill riverbanks — is one of the most historically significant SLF zones in the region, and the entire Main Line suburban corridor now faces sustained infestation pressure.
Highest activity zones
SLF Hotspots in Montgomery County, PA
Valley Forge National Historical Park (TOH along riverbanks)
Active zone
Schuylkill River Trail
Active zone
Fort Washington State Park
Active zone
Skippack corridor
Active zone
North Penn area
Active zone
Primary SLF food source
Tree of Heaven in Montgomery County, PA
Tree of Heaven is widespread throughout Montgomery County's Schuylkill River corridor and stream valleys, creating continuous SLF habitat from the Philadelphia border through the heart of the Main Line. Valley Forge National Historical Park has dense Ailanthus populations along riverbanks that fuel SLF establishment across the park's historic grounds. The Skippack corridor and North Penn area road margins have additional ToH concentrations that support large SLF populations through the fall season.
Identify Tree of Heaven →Local action resources
What To Do in Montgomery County, PA
Report a Sighting
Every sighting in Montgomery County, PA maps the invasion front. Report directly to PA 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 PA State Guide
County-level data, quarantine zones, treatment guides, and agency resources for the entire state.
See the full PA guide →Community intelligence
Live Sighting Map
See where SLF has been spotted near you in Montgomery County, PA. Add your own sighting to help map the front.
Open the Map →Free weekly fight briefing
Fight SLF in Montgomery County, PA.
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