The Spotted Lanternfly (Lycorma delicatula), or SLF, is an invasive insect pest originating from Asia. While its primary host is the tree of heaven (Ailanthus altissima), it can also feed on a wide range of plants, including grapevine, hops, maple, walnut, and fruit trees. The full consequences of SLF are still being studied, but it is anticipated to have a negative impact on the agricultural and tourism industries, and potentially affect New York’s forests.
First discovered in Pennsylvania in 2014, SLF was detected in New York in 2020. The initial New York State infestation was identified in Staten Island in August 2020. For the latest map of current infestation locations in the Northeast, including New York, please refer to Cornell’s Integrated Pest Management site: up-to-date map of current infestation locations in the Northeast, including New York.
Identifying Spotted Lanternfly
Spotted Lanternfly adults are striking insects. Nymphs, or young SLF, emerge black with white spots, later developing red coloration before becoming adults. Black nymphs are visible from April to July, while red nymphs appear from July to September.
Adults emerge in July, measuring roughly 1 inch in length and ½ inch wide when at rest, with distinctive wings. Their forewings are grayish with black spots. The lower parts of their hindwings are red with black spots, and the upper sections are dark with a white stripe.
In the fall, adults deposit 1-inch-long egg masses on various surfaces, from tree trunks and rocks to vehicles and even firewood. Freshly laid egg masses are smooth, brownish-gray, and possess a shiny, waxy coating.
Nymph stages of Spotted Lanternfly: late nymph (left) and early nymph (right)
Signs of a Spotted Lanternfly Infestation
Recognizing the signs of an infestation is crucial for early detection and management. Keep an eye out for:
- Sap oozing or weeping from small wounds on tree trunks. This appears wet and might emit a fermented odor.
- One-inch-long egg masses. New masses are brownish-gray, waxy, and mud-like, while older masses are brown and scaly.
- Honeydew, a sticky liquid waste excreted by SLF, accumulating under plants. This can lead to the growth of black sooty mold.
Older Spotted Lanternfly egg masses on a tree
Impacts of Spotted Lanternfly
SLF represents a significant threat to New York’s agricultural sector, negatively affects outdoor recreation, and may impact forest health.
- Both adults and nymphs use piercing-sucking mouthparts to feed on the sap of over 70 plant species.
- This feeding, often by thousands of SLF, stresses plants, making them more susceptible to diseases and attacks from other insects.
- SLF excrete substantial amounts of sticky “honeydew,” which:
- Encourages the growth of sooty molds that impede plant photosynthesis, harming plant growth and fruit production.
- Attracts swarms of insects, disrupting outdoor activities and tourism.
- Can become a nuisance, coating hair, clothing, and belongings when people are outdoors.
New York’s annual apple and grape yields, with a combined value exceeding $350 million, are particularly vulnerable to SLF. The full extent of the economic damage this insect could inflict remains uncertain.
How Spotted Lanternfly Spreads
Spotted Lanternfly primarily spreads through human-mediated transport. They lay eggs on vehicles, firewood, outdoor furniture, and stone, which can be inadvertently moved to new locations, facilitating the insect’s dispersal. Understanding how they spread is key to preventing them from flying into new territories.
Management and Control Efforts
The DEC is collaborating with the Department of Agriculture and Markets (AGM) and the US Department of Agriculture (USDA) to combat SLF. Early intervention is more cost-effective and manageable, so the focus is on detecting and treating infestations promptly.
A comprehensive plan is in place to detect and prevent further SLF spread in New York. Extensive trapping surveys are underway in high-risk areas throughout the state, along with inspections of nursery stock, stone shipments, commercial transports, and more. DEC and partner organizations urge public vigilance in spotting this pest.
Exterior Quarantine Measures
To slow SLF’s advance, AGM has implemented a quarantine restricting the movement of goods into New York from quarantined zones in Delaware, New Jersey, Pennsylvania, Maryland, and Virginia. Regulated items like packing materials, landscaping and construction equipment, and nursery stock require certificates of inspection from affected states. AGM and its partners are conducting inspections across New York to check for SLF and compliance with regulations. Detailed information and a list of regulated articles are available on AGM’s website.
Protective Zones in New York
To facilitate early detection and rapid response, DEC has established Protective Zones encompassing 20 counties near PA and NJ infestations. These zones enable DEC and partners to conduct surveys, monitoring, and management activities to locate and control SLF spread. Protective Zones are in: Bronx, Broome, Chemung, Chenango, Delaware, Dutchess, Greene, Kings, Nassau, Orange, Otsego, Putnam, Queens, Richmond, Rockland, Suffolk, Sullivan, Tioga, Ulster, and Westchester counties.
How You Can Contribute to SLF Control
The NYS Integrated Pest Management program provides guidance on managing SLF on your property, including egg mass destruction, spread prevention, and methods for eliminating found insects.
- Learn to accurately identify SLF in all its life stages.
- Thoroughly inspect outdoor items such as firewood, vehicles, and furniture for egg masses, especially if traveling from areas known to have SLF.
- If visiting states with SLF infestations, diligently check equipment and gear before leaving. Scrape off any egg masses you find.
- Destroy egg masses by scraping them into a container of hot, soapy water or a baggie/jar of hand sanitizer.
If you are located outside of the core infested counties (Dutchess, Nassau, New York City, Orange, Putnam, Rockland, Suffolk (except for North Fork), Sullivan, Ulster, Westchester), immediate reporting of SLF sightings is crucial. Please follow these steps:
- Capture images of the insect, egg masses, and/or infestation signs as described earlier. Include a size reference in your photos, like a coin or ruler. Email photos and sighting details to: [email protected].
- Note the precise location: address, road intersections, landmarks, or GPS coordinates.
After reporting SLF in your area and collecting a sample if possible, eliminate any additional SLF you encounter by stepping on them or crushing them.
