Spotted Lanternfly in New Jersey: From Ground Zero to Statewide Infestation

When spotted lanternfly jumped from Pennsylvania to New Jersey in 2018, it confirmed what entomologists had predicted: this pest was not staying put. New Jersey, sharing 48 miles of border with Pennsylvania, was the second state in the country to confirm an established SLF population — and it has spent the years since watching a localized border infestation become a statewide crisis.

By 2026, New Jersey has confirmed spotted lanternfly in all 21 counties. The state's combination of dense suburban and urban development, major transportation infrastructure, and a cluster of economically significant vineyards and orchards in the southwestern counties has made NJ a critical front in the national SLF response. The New Jersey Department of Agriculture (NJDA) has issued one of the most extensive quarantine programs in the country, and Rutgers Cooperative Extension has produced some of the most widely-cited SLF research in the region.

New Jersey's SLF History: The Second State Hit

Pennsylvania's Berks County infestation was confirmed in September 2014. By 2018, four years of natural spread and hitchhiker transport had brought SLF across the Delaware River. New Jersey's first confirmed detections came in Warren County — the westernmost New Jersey county, directly across the Delaware from Bucks and Warren counties in Pennsylvania — in 2018.

The Warren County detection was only the beginning. SLF spread rapidly north along the Delaware River corridor (which carries heavy truck, rail, and recreational vehicle traffic), south into Hunterdon County and Salem County, and east into the dense New Jersey suburban counties via I-78 and I-287. By 2020, the pest had been confirmed in nine counties. By 2022, all but the most easterly Shore counties had confirmed populations. By 2024, all 21 counties were confirmed infested.

The I-78 corridor from Phillipsburg to Newark was a primary east–west spread vector. This interstate, which runs directly from the Pennsylvania state line through heavily infested Union and Essex counties to the Port of New York/New Jersey, effectively seeded the entire central New Jersey corridor with SLF within two to three seasons of first introduction.

The Statewide Quarantine: What It Means for NJ Residents and Businesses

New Jersey was among the first states to implement a comprehensive SLF quarantine. As of 2026, the entire state of New Jersey is under quarantine — meaning all 21 counties are subject to regulations governing the movement of regulated articles that could carry SLF.

What New Jersey's quarantine covers:

Under NJ's quarantine regulations (aligned with the federal USDA APHIS regulations under the Plant Protection Act), any "regulated article" moved out of the quarantine zone requires a permit or compliance agreement. Regulated articles include:

Nursery stock and plants
Logs, lumber, firewood, and bark
Outdoor household articles including furniture, grills, and recreational equipment stored outside
Vehicles, including cars, trucks, trailers, RVs, and rail cars, that have been parked within the quarantine zone
Landscaping, hardscape stone, soil, and fill material

For businesses (landscapers, nurseries, lumber yards, construction companies, and any company moving goods or equipment in and out of New Jersey), compliance agreements with NJDA are required. Contact NJDA at 609-292-5440 or visit nj.gov/agriculture for compliance program details.

For homeowners and individuals, the quarantine primarily asks for vigilance: inspect vehicles, trailers, and outdoor items before moving them out of state, particularly during egg mass season (September through May).

Urban and Suburban NJ: Bergen, Essex, Hudson, and Passaic

No conversation about spotted lanternfly in New Jersey is complete without acknowledging the dense urban and suburban counties of northeastern New Jersey — Bergen, Essex, Hudson, Passaic, and Union — which form one of the most densely populated zones in the United States and are now heavily infested with SLF.

Bergen County, directly south of New York City across the George Washington Bridge, confirmed SLF by 2020 and now has established populations throughout. Tree of heaven grows aggressively along the Palisades corridor, Route 4, and the Garden State Parkway right-of-ways — providing source population reservoirs that continuously re-seed suburban neighborhoods. Essex County (including Newark, Montclair, and the Oranges) has significant TOH growth along highway and rail corridors and confirmed SLF throughout most of the county by 2021. Urban Newark — with its extensive freight and industrial areas adjacent to Port Newark — is a documented vector for long-distance SLF spread via shipping containers and vehicles. Hudson County (including Jersey City and Hoboken) is among the most urban environments where SLF is established in the U.S., demonstrating that this pest thrives even in high-density built environments where pockets of TOH and ornamental trees persist. What this means: For the millions of NJ residents in these northeastern counties, SLF is not an abstract rural pest — it is a backyard, balcony, and parking lot reality. Apartment dwellers are seeing SLF on outdoor furniture; commuters are finding egg masses on vehicles; residents with any outdoor green space are dealing with aggregations on trees and fencing in late summer.

Hunterdon and Salem Counties: NJ's Wine Region Under Pressure

While northeastern NJ gets the most press, the southwestern counties of Hunterdon and Salem are home to New Jersey's wine country — and some of the most economically vulnerable agricultural land in the state.

Hunterdon County is home to roughly two-thirds of New Jersey's licensed wineries. The rolling Piedmont terrain west of the Sourland Mountains and along the Delaware River valley is prime viticulture land — and prime SLF habitat, with abundant TOH in hedgerows, forest edges, and disturbed roadside corridors. Salem County hosts additional wine grape and fruit tree operations, as well as commercial hops production — another highly susceptible SLF host. The southwestern NJ agricultural community was among the first in the state to sound the alarm about SLF's economic threat, and Rutgers Cooperative Extension has maintained a dedicated SLF viticulture program since 2019.

Rutgers research on SLF and wine grapes, conducted in cooperation with NJ winegrowers, has produced specific recommendations for New Jersey viticulture conditions:

Dinotefuran trunk band or soil drench applications on vines in June through early August, timed to adult emergence
Circle trap deployment at vineyard perimeters and on TOH stands at vineyard borders
Bifenthrin perimeter sprays at field edges (not on vines or within bloom period) during peak adult pressure
Complete quarantine compliance for any plant material, tools, or equipment moved between vineyard properties

If you are a New Jersey viticulture or orchardist: Contact Rutgers Cooperative Extension at njaes.rutgers.edu/spotted-lanternfly/ for current New Jersey-specific recommendations.

How to Report Spotted Lanternfly in New Jersey

Online reporting:

NJDA reporting portal: nj.gov/agriculture — search "spotted lanternfly"
The Rutgers NJAES SLF reporting page at njaes.rutgers.edu/spotted-lanternfly/
iNaturalist: tag observations as Lycorma delicatula — feeds directly into USDA and NJDA monitoring databases

Phone:

NJDA Division of Plant Industry: 609-292-5440

What to include when reporting:

County and municipality (city/township)
Nearest cross streets or address
Date of observation
Life stage observed: egg mass, nymph (black with white spots for 1st–3rd instar; red and black for 4th instar), or adult
Clear photo if possible — particularly important for new county confirmations

What New Jersey Residents Should Do Now

By Season

Adult season (July–October, peak August–September):

Hand-squish every adult you can on sight
Install or maintain circle traps on tree of heaven and other host trees
Apply dinotefuran trunk bands to high-value ornamental trees and any grapevines or hops on your property
Spray bifenthrin contact spray on heavily infested non-flowering areas — follow label; apply at dusk to avoid pollinators

Egg-laying and scraping season (September–April):

Begin searching for egg masses as soon as you see adults aggregating in late September
Check all surfaces: tree trunks, outdoor furniture, stone walls, vehicles, play equipment
Scrape into a bag with isopropyl alcohol and seal — see our egg scraping guide for technique

Spring nymph season (April–June):

Install or re-install circle traps before first hatch (mid-April in NJ's climate)
First and second instars are highly vulnerable to diatomaceous earth and insecticidal soap as supplemental controls
Check bags weekly during active climbing season

Tree of Heaven in New Jersey

New Jersey's most invasive tree is a direct enabler of its SLF infestation. TOH grows throughout the state — in yards, parks, highway medians, rail rights-of-way, and virtually every disturbed soil environment. New Jersey has no restrictions on TOH removal from private property.

Rutgers Cooperative Extension recommends an integrated approach: for small TOH trees (under 4 inches trunk diameter), cut-stump treatment with triclopyr or glyphosate applied immediately to the cut surface is effective. For larger specimens on infested properties, the "trap tree" strategy — applying dinotefuran to kill SLF adults aggregating on a designated TOH tree — can reduce the local population before the tree is removed in fall.

Do not attempt to "simply cut" large TOH — the tree aggressively resprouts from the root system and the stumps and roots need herbicide treatment to prevent vigorous regrowth.

Key Sources

New Jersey Department of Agriculture. "Spotted Lanternfly." nj.gov/agriculture.
Rutgers New Jersey Agricultural Experiment Station. "Spotted Lanternfly Management in NJ." njaes.rutgers.edu/spotted-lanternfly/.
Cooperband, M.F., et al. (2021). "Spotted Lanternfly (Lycorma delicatula) Distribution in New Jersey." Environmental Entomology.
USDA APHIS. "Spotted Lanternfly Quarantine Information." aphis.usda.gov.
Penn State Extension. "Spotted Lanternfly." extension.psu.edu/spotted-lanternfly.

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