Spotted Lanternfly inUnion County, PASPOTTED LANTERNFLY GUIDE
Union County — confirmed for SLF in 2018 — occupies the Susquehanna River valley in central Pennsylvania, with Lewisburg as county seat and home to Bucknell University, a nationally recognized liberal arts and engineering institution. The campus and Lewisburg borough sit directly on the West Branch Susquehanna River, where riparian corridors provide natural SLF spread pathways connecting Union County populations to neighboring Snyder and Northumberland counties. The I-80 interchange near Lewisburg is a critical freight node that reinforces SLF populations through vehicle traffic from established eastern Pennsylvania infestation zones. Kelly Township's agricultural areas and the broad Buffalo Valley corridor west of Lewisburg represent some of the most productive farmland in the county, where SLF feeding pressure on ornamental and agricultural trees is an ongoing concern for approximately 45,000 residents.
Highest activity zones
SLF Hotspots in Union County, PA
Bucknell University campus (Lewisburg borough)
Active zone
Susquehanna River at Lewisburg waterfront
Active zone
I-80 near interchange corridor
Active zone
Kelly Township agricultural areas
Active zone
US Buffalo Valley corridor
Active zone
Primary SLF food source
Tree of Heaven in Union County, PA
Tree of Heaven is established along the West Branch Susquehanna River waterfront and I-80 road margins throughout Union County, creating primary SLF dispersal pathways through this central Pennsylvania river valley landscape. Bucknell University campus edges and the Lewisburg borough street margins have Ailanthus colonization that supports SLF establishment in the county's most visible public spaces. Kelly Township agricultural field margins and the Buffalo Valley corridor road edges are priority monitoring zones as SLF populations continue to spread through this compact but agriculturally and academically significant county.
Identify Tree of Heaven →Local action resources
What To Do in Union County, PA
Report a Sighting
Every sighting in Union County, PA maps the invasion front. Report directly to Pennsylvania 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 Pennsylvania State Guide
County-level data, quarantine zones, treatment guides, and agency resources for the entire state.
See the full Pennsylvania guide →Community intelligence
Live Sighting Map
See where SLF has been spotted near you in Union County, PA. Add your own sighting to help map the front.
Open the Map →Free weekly fight briefing
Fight SLF in Union County, PA.
One email per week. Your zip code. Your threat level. Your action plan. Know exactly what to do this week in Union County, PA.