Spotted Lanternfly inHillsborough County, NHSPOTTED LANTERNFLY GUIDE
Hillsborough County is New Hampshire's most populous county and the economic heart of the state, anchored by Manchester and Nashua — two cities that sit astride I-93, the primary freight and commuter corridor from Massachusetts. Designated a watch zone in 2025, Hillsborough County faces intense SLF pressure as the pest establishes in northeastern Massachusetts and inches toward the NH border. Nashua, the county's southernmost major city, is separated from SLF-confirmed sites in Massachusetts by only a few miles of the Nashua River valley. Hudson, directly on the MA border along the Merrimack River, is arguably the county's highest-risk municipality. Manchester, the state's largest city and a major freight hub, is a critical monitoring priority given the volume of trucks, rail, and commercial vehicles moving along I-93 from SLF-active regions. The Merrimack River corridor threading through Nashua, Merrimack, Manchester, and beyond provides both a natural dispersal pathway and Ailanthus habitat that could support rapid population establishment once SLF arrives.
Highest activity zones
SLF Hotspots in Hillsborough County, NH
Manchester
Active zone
Nashua
Active zone
Merrimack
Active zone
Milford
Active zone
Hudson
Active zone
Primary SLF food source
Tree of Heaven in Hillsborough County, NH
The Merrimack River corridor is Hillsborough County's primary SLF threat pathway — the river valley supports Ailanthus in disturbed floodplain margins from the Massachusetts border through Nashua, Merrimack, and Manchester, providing a connected dispersal highway aligned with the county's population centers and freight routes. The I-93 Manchester hub is a freight interchange serving major logistics operations that regularly receive goods from SLF-established zones in Massachusetts, Connecticut, New York, and Pennsylvania, making it a high-priority inspection and monitoring site for egg mass detection on vehicles and shipping materials. Former textile mill brownfields throughout Nashua and Manchester's urban cores — along the Merrimack, Souhegan, and Nashua Rivers — provide disturbed soil and edge habitat highly conducive to Ailanthus establishment and SLF colonization once introduced. Hudson along the MA border is a priority early-detection zone where any SLF sighting should be reported immediately to the NH Department of Agriculture.
Identify Tree of Heaven →Local action resources
What To Do in Hillsborough County, NH
Report a Sighting
Every sighting in Hillsborough County, NH maps the invasion front. Report directly to NH Dept 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 NH State Guide
County-level data, quarantine zones, treatment guides, and agency resources for the entire state.
See the full NH guide →Community intelligence
Live Sighting Map
See where SLF has been spotted near you in Hillsborough County, NH. Add your own sighting to help map the front.
Open the Map →Free weekly fight briefing
Fight SLF in Hillsborough County, NH.
One email per week. Your zip code. Your threat level. Your action plan. Know exactly what to do this week in Hillsborough County, NH.