Spotted Lanternfly inDelaware County, PASPOTTED LANTERNFLY GUIDE
Delaware County — known locally as "Delco" — borders Philadelphia to the southwest and was confirmed for SLF in 2018. Multiple SEPTA rail lines running through the county serve as critical spread vectors, moving SLF populations from Philadelphia into the suburbs and vice versa. Tyler Arboretum is one of the most important SLF monitoring sites in the region, with long-running population studies that have contributed to regional SLF research. Chester Creek corridor and Ridley Creek State Park are significant SLF zones, and Media — the county seat — faces ongoing infestation pressure throughout the growing season.
Highest activity zones
SLF Hotspots in Delaware County, PA
Tyler Arboretum (active SLF monitoring site)
Active zone
Ridley Creek State Park
Active zone
Chester Creek Greenway
Active zone
Media town center
Active zone
SEPTA Media/Wawa line corridor
Active zone
Primary SLF food source
Tree of Heaven in Delaware County, PA
Tree of Heaven is established along Chester Creek, the SEPTA Media/Wawa rail corridor, and road margins throughout Delaware County, creating continuous SLF habitat corridors connecting Philadelphia populations to the suburban interior. Tyler Arboretum has been an important site for monitoring SLF interactions with diverse tree species, and the Chester Creek Greenway Ailanthus populations continue to fuel SLF spread through this densely suburban county. Ridley Creek State Park road margins and stream banks are additional priority ToH monitoring zones.
Identify Tree of Heaven →Local action resources
What To Do in Delaware County, PA
Report a Sighting
Every sighting in Delaware 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 Delaware County, PA. Add your own sighting to help map the front.
Open the Map →Free weekly fight briefing
Fight SLF in Delaware County, PA.
One email per week. Your zip code. Your threat level. Your action plan. Know exactly what to do this week in Delaware County, PA.