Spotted Lanternfly in Suffolk County: What Long Island Homeowners Need to Know

Spotted Lanternfly Has Arrived in Suffolk County

The spotted lanternfly (Lycorma delicatula), one of the most damaging invasive pests to reach the northeastern United States in decades, is now established on Long Island — and Suffolk County is in the crosshairs of its continued spread. What began as a Pennsylvania problem when SLF was first detected in 2014 has become a regional emergency affecting New York State agriculture, landscaping, and residential trees throughout the region.

If you live in Suffolk County — particularly in communities with mature hardwood trees, vineyards, orchards, or significant ornamental plantings — understanding spotted lanternfly, what it does, and what you can do about it is now a genuine property management priority.

What Is Spotted Lanternfly?

Spotted lanternfly is a planthopper native to China, Vietnam, and Bangladesh. It feeds on the sap of over 70 plant species using piercing mouthparts to extract phloem — the nutrient-rich fluid that trees use to transport energy from leaves to roots. Because it feeds on phloem rather than leaf tissue, the damage it causes is not immediately visible but is cumulative and can be fatal to heavily infested trees and vines.

Adult spotted lanternflies are distinctive: approximately 1 inch long, with tan or grayish wings covered in black spots when at rest, revealing bright red hindwings when startled or in flight. Egg masses look like dried mud smeared on a flat surface — about 1 inch long, grayish-brown, and often found on tree bark, outdoor furniture, fences, vehicles, and almost any flat surface.

The Life Cycle Homeowners Need to Know

• Eggs (October–May): Egg masses overwinter on trees, fences, outdoor furniture, firewood, vehicles, and any outdoor surface. Each mass contains 30–50 eggs.

• Nymphs (May–July): Early instars are black with white spots. Late-stage nymphs develop red coloring. All nymph stages are wingless.

• Adults (July–November): Winged adults emerge in late summer and are most visible August through October. Adults feed aggressively before cold weather and lay egg masses before dying.

The egg mass stage is particularly important for Long Island homeowners: egg masses on vehicles, outdoor equipment, and firewood are the primary mechanism by which SLF spreads to new locations. Before transporting anything that has been stored outdoors — firewood, trailers, gardening equipment — inspect carefully for egg masses and scrape any found into a bag with hand sanitizer.

The Threat to Suffolk County's Trees and Agriculture

The North Fork Wine Country Connection

Suffolk County is home to one of the most important wine-producing regions on the East Coast. The North Fork American Viticultural Area — centered in Riverhead, Southold, and surrounding communities — contains dozens of commercial wineries and vineyards that collectively represent a significant portion of New York State's wine industry.

Spotted lanternfly is particularly devastating to grapevines. The pest feeds directly on vines, excretes a sticky waste called honeydew that promotes black sooty mold growth, and weakens vines to the point where fruit production is severely reduced or eliminated. Pennsylvania's wine industry, orchards, and vineyards suffered significant losses in the years following SLF establishment there — and Long Island's wine industry faces the same threat as SLF establishes on the Island.

Tree of Heaven: The Host That Accelerates Spread

Spotted lanternfly's preferred host plant is Ailanthus altissima — the tree of heaven — an invasive tree species that is unfortunately extremely common throughout Long Island's developed areas, roadsides, and disturbed landscapes. Tree of heaven grows aggressively along fence lines, in vacant lots, along railroad corridors, and in disturbed areas throughout central and western Suffolk County.

The presence of abundant tree of heaven provides SLF with a reliable food source that accelerates population growth before the pest moves to grapevines, apples, hops, and ornamental trees. Managing tree of heaven on your property reduces local SLF harborage — contact your local cooperative extension for guidance on legal removal methods.

Impact on Ornamental Trees and Home Landscapes

Beyond vineyards and agriculture, SLF causes significant damage to ornamental hardwoods common in Suffolk County home landscapes — maples, oaks, birches, walnuts, cherry trees, and apple trees are all susceptible. A severely infested ornamental tree shows weeping sap wounds, honeydew accumulation on leaves and surfaces beneath the tree, sooty mold on leaves and outdoor furniture, and eventual crown dieback in heavily affected specimens.

The honeydew produced by SLF feeding is sticky and can accumulate on outdoor furniture, decks, and vehicles parked under infested trees — attracting bees, wasps, and other insects to the sticky residue.

Identifying Spotted Lanternfly Activity on Your Property

Signs to look for:

• Adults (July–November): 1-inch insects with spotted gray wings resting on tree trunks, particularly on the lower 4 feet of tree bark. They jump when disturbed and fly short distances.

• Egg masses (October–June): Grayish-brown patches on tree bark, fences, deck boards, outdoor furniture, rocks, and vehicles. Fresh masses have a waxy coating; older masses look like cracked gray mud.

• Nymphs (May–July): Small, wingless black insects with white spots on lower tree trunks and on herbaceous vegetation near trees.

• Honeydew and sooty mold: Sticky residue on surfaces beneath infested trees, followed by black sooty mold growth on leaves, outdoor furniture, and decks.

• Weeping wounds: Fermented sap oozing from tree trunks at feeding sites.

What to Do If You Find Spotted Lanternfly

Report It

New York State DEC and Cornell Cooperative Extension request that all SLF sightings be reported, particularly in counties where the pest is newly established. Report sightings through the New York State DEC's online reporting tool or contact your local Cornell Cooperative Extension office. Reporting helps track the spread and prioritize management resources.

Destroy Eggs and Adults

Inspect Before Moving

Before moving any outdoor items — firewood, vehicles, trailers, outdoor furniture, garden equipment — check thoroughly for egg masses. SLF spread is primarily human-assisted through the movement of infested materials.

Professional Treatment Options

Licensed pest control professionals can apply targeted treatments to reduce SLF populations on your property. Options include:

• Tree bark banding: Sticky banding applied around tree trunks captures crawling nymphs before they reach the canopy

• Systemic tree treatment: Insecticide products applied to tree root zones or injected into the trunk are absorbed by the tree and affect SLF feeding on treated trees

• Perimeter treatment: Targeted applications around property perimeters during peak adult movement periods

Suffolk County Pest Control provides SLF management consultations for Suffolk County homeowners. Call (631) 894-9702 to discuss options for your property.

The Long-Term Outlook

Spotted lanternfly is established in Long Island and is not going away. The realistic goal is population management — reducing SLF to levels that minimize damage to your trees and outdoor living areas, rather than elimination. As with tick management and mosquito control, professional assistance combined with consistent property-level management is the most effective approach.

Stay informed through the Cornell Cooperative Extension's Long Island programs, which provide the most current guidance on SLF management for the region.