The Spread Map
Every sighting you report helps researchers track spread, triggers targeted intervention, and shows your neighbors exactly where to watch out. This is real data that matters.
DC / MD / VA Confirmed Sightings
Data via iNaturalist ↗Report a Sighting
Takes 60 seconds. Your report goes to our map and to iNaturalist's citizen science database.
Why report? Your report helps researchers and neighbors know where SLF is most active — triggering targeted intervention and alerting people nearby.
Also spotted the host plant?
Report a Tree of Heaven
Map the #1 SLF food source in your area
Confirmed DC/MD/VA Jurisdictions
Arlington County, VA
Heavy Infestation
Fairfax County, VA
Heavy Infestation
Alexandria, VA
Heavy Infestation
Falls Church, VA
Confirmed — Moderate
Prince William County, VA
Confirmed — Moderate
Montgomery County, MD
Heavy Infestation
Prince George's County, MD
Heavy Infestation
Washington, DC
Confirmed — Moderate
Frederick County, MD
Confirmed — Moderate
Howard County, MD
Confirmed — Moderate
Sources: USDA APHIS, Virginia DGIF, Maryland MDA, DC DOEE. Updated July 2026.