The Spotted Lanternfly (Lycorma delicatula) is an invasive planthopper native to Asia, first detected in the United States in Pennsylvania in 2014. Adult and nymph stages feed on plant sap using piercing-sucking mouthparts, weakening host plants and sometimes causing death, particularly in grapevines and saplings. The pests also excrete a sugary substance called honeydew, which fosters the growth of black sooty mold that reduces plant photosynthesis and creates a public nuisance. Effective management requires a combination of immediate hands-on efforts and long-term environmental modifications to curb the spread and reduce local populations.
Immediate Physical and Mechanical Removal
The simplest method for reducing the local population is the “see it, squash it” approach. Both the colorful nymph stages and the winged adults can be crushed or swatted to eliminate them on sight. Consistently destroying individual insects prevents them from reproducing and laying egg masses.
A single female can lay one or two egg masses, each containing 30 to 50 eggs, making their destruction a high-impact control method. Egg masses resemble a smear of mud or putty and are found from late fall through spring on tree trunks, stones, outdoor furniture, or vehicles. To destroy an egg mass, scrape it off the surface using a stiff card or putty knife.
The scraped material must then be immediately sealed in a plastic bag or container filled with rubbing alcohol or hand sanitizer. This step ensures that all the eggs are killed, as simply scraping them onto the ground may not be sufficient to prevent hatching. This method is most effective during the cooler months when the adults have died off and the unhatched eggs are stationary.
For managing populations on tree trunks without chemicals, non-toxic physical traps can be deployed, capitalizing on the insect’s habit of crawling up trees. Sticky bands wrapped around the trunk capture nymphs as they attempt to climb. However, sticky bands can inadvertently capture beneficial insects, small birds, and other non-target wildlife.
If sticky bands are used, they must be covered with a protective barrier, such as a layer of vinyl window screening, to prevent accidental entanglement of other animals. A more selective alternative is the circle trap, a funnel-style device that does not use adhesive. This trap directs the climbing nymphs and adults into a collection container from which they cannot escape, offering an effective, non-toxic way to capture large numbers.
Long-Term Prevention and Habitat Modification
Addressing the Spotted Lanternfly’s preferred habitat is key to control. The invasive Tree of Heaven (Ailanthus altissima) is a favored host plant, and its presence can significantly increase the lanternfly population in an area. Removing this tree reduces the primary food source and reproductive site, making the environment less attractive to the pest.
Simply cutting down a Tree of Heaven is counterproductive because the stump will aggressively sprout numerous new shoots from its root system. Effective removal requires treating the stump with a targeted herbicide immediately after cutting to prevent re-sprouting. Landowners can also employ a “trap tree” strategy, where a few male Tree of Heaven are intentionally left standing and treated with a systemic insecticide to draw in and eliminate the pests.
Protecting high-value ornamental or fruit trees, such as maples or grapevines, can be achieved using physical barriers. Fine mesh netting can be draped over sensitive plants to prevent both adult lanternflies from laying eggs and nymphs from feeding. This non-chemical approach is particularly useful for smaller trees and shrubs that are easily covered.
Preventing the spread of the insect to new areas is essential for long-term control. The Spotted Lanternfly is a hitchhiker, moving easily on vehicles, firewood, outdoor equipment, and other items. Local agricultural departments often require residents in infested areas to perform a “Look Before You Leave” inspection of their belongings and vehicles to ensure no egg masses or insects are transported.
Reporting sightings to state or local agricultural extension offices is important. These official reports help regulatory agencies track the pest’s spread, define quarantine zones, and coordinate professional management efforts across the region. Community vigilance and compliance with local guidelines are important for containing the overall population.
Targeted Chemical and Biological Treatments
For instances of heavy infestation or for protecting commercially valuable crops, the application of chemical or biological agents may be necessary. Homeowners have access to several low-impact contact sprays that can kill nymphs and adults upon direct application. These include insecticidal soap, neem oil, and horticultural oils, which work by smothering the insect or disrupting its cellular function.
These contact sprays are best used for spot treatments on small populations, as they offer no residual protection once they dry, and they require a direct hit to be effective. For larger trees or more persistent infestations, systemic insecticides offer longer-lasting control. These chemicals are absorbed by the plant and move through the vascular system, making the sap toxic to the feeding lanternflies.
Systemic treatments, which often contain active ingredients like imidacloprid, are applied as a soil drench or bark spray and are most effective against the adult stage. Because systemic products can harm pollinators, apply them only after the tree has finished flowering, or use them on host plants that do not attract bees. Professional arborists are recommended for applying these products due to the specialized equipment and knowledge required.
Biological controls are being investigated. Research has focused on the fungal pathogen Beauveria bassiana, which infects and kills insects. While commercially available formulations of this fungus exist, results in field trials have been inconsistent, and it is not yet a primary recommendation for homeowner use. Always read and follow all product label instructions, as they contain information regarding safety, application rates, and potential risks to non-target organisms.