Spotted Lanternfly inCalvert County, MDSPOTTED LANTERNFLY GUIDE
Calvert County occupies a narrow peninsula between the Chesapeake Bay and the Patuxent River on Maryland's western shore — confirmed for SLF in 2022 as populations advanced south through the Southern Maryland corridor. The county's scenic agricultural character, Chesapeake Bay shoreline, and Calvert Cliffs State Park create a unique SLF landscape where natural spread corridors intersect with growing suburban development radiating from Prince Frederick. The Patuxent River forms the county's western border, providing a natural SLF spread pathway shared with neighboring Anne Arundel and Charles counties. Calvert County serves as the gateway to Southern Maryland, and Route 4 is the primary spread vector carrying SLF introduction risk from the established Baltimore-Washington infestation zone southward.
Maryland is under a statewide spotted lanternfly quarantine as of March 2026. Moving regulated articles out of Maryland requires inspection.
Highest activity zones
SLF Hotspots in Calvert County, MD
Calvert Cliffs State Park
Active zone
Patuxent River corridor
Active zone
Prince Frederick downtown area
Active zone
Route 4 corridor (Southern Maryland gateway)
Active zone
Chesapeake Bay western shoreline
Active zone
Primary SLF food source
Tree of Heaven in Calvert County, MD
Tree of Heaven is present along Calvert County's Route 4 corridor and stream valleys draining to the Patuxent River, providing SLF dispersal pathways from the established Anne Arundel and Prince George's County populations southward into this scenic peninsula county. Calvert Cliffs State Park road margins and the Chesapeake Bay shoreline access roads have Ailanthus colonization at the forest-waterfront interface. Prince Frederick downtown margins and Patuxent River riparian edges are priority monitoring zones as SLF populations continue to advance through this agricultural and Chesapeake Bay gateway county.
Identify Tree of Heaven →Local action resources
What To Do in Calvert County, MD
Report a Sighting
Every sighting in Calvert County, MD maps the invasion front. Report directly to Maryland 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 MD State Guide
County-level data, quarantine zones, treatment guides, and agency resources for the entire state.
See the full MD guide →Community intelligence
Live Sighting Map
See where SLF has been spotted near you in Calvert County, MD. Add your own sighting to help map the front.
Open the Map →Free weekly fight briefing
Fight SLF in Calvert County, MD.
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