The Spotted Lanternfly (Lycorma delicatula) is an invasive planthopper that poses a significant threat to agriculture and ornamental plants across the United States. This pest feeds on the sap of over 70 different plant species, weakening hosts like grapevines, fruit trees, and maples. While the adult stage is highly mobile, the immobile nymph stage is vulnerable to targeted control efforts, offering the best opportunity for localized population reduction. Eliminating these young, flightless insects is a direct way to protect your landscape and slow the spread of this destructive species.
Identifying the Nymph Stages and Locations
Successful management begins with accurately identifying the nymph stages, which occur between May and August. The Spotted Lanternfly progresses through four distinct instars before reaching adulthood. The first three stages share a similar appearance: small, black bodies covered in bright white spots.
These early instars are highly mobile and frequently feed on the new, softer growth of various plants, often congregating in large numbers. In July, the nymph enters its fourth and final instar, undergoing a noticeable color change. This mature nymph retains the white spots but develops striking patches of vibrant red coloration on its body.
All nymph stages tend to crawl up vertical surfaces, a behavior that guides many mechanical control strategies. They are commonly observed on their preferred host plant, the invasive Tree of Heaven (Ailanthus altissima), but also gather on rose bushes, grapevines, and trees with smooth bark. The nymphs use piercing-sucking mouthparts to feed on plant sap, and when disturbed, they jump quickly to escape.
Physical and Mechanical Removal Techniques
Physical removal methods provide immediate, non-chemical control and are highly effective against the nymph stage. The simplest method for small numbers is crushing the insects upon sighting. For larger groups congregated on accessible surfaces, a handheld or shop vacuum is an efficient tool for mass removal. The vacuum’s collection canister should contain a few inches of soapy water to ensure the trapped insects are killed upon collection.
To exploit the nymph’s instinct to climb, a mechanical trapping system can be installed around tree trunks. Sticky bands wrapped around the trunk are effective at capturing early instars as they ascend the tree. These bands must be monitored frequently, as a full band can quickly be crossed by subsequent insects, nullifying effectiveness.
A serious consideration when using sticky bands is the risk of unintentionally trapping non-target organisms, such as small birds, bats, or beneficial insects. To mitigate this hazard, sticky banding material must be covered with a protective barrier, such as wire caging or screening. This barrier should be secured above the sticky surface while flaring outward slightly to prevent other animals from making contact with the adhesive.
Targeted Insecticidal Treatments
When physical removal is impractical for large populations, targeted contact sprays offer control by focusing on the nymphs’ susceptibility to direct exposure. Several homeowner-accessible products are effective contact killers, meaning the spray must physically touch the insect to work. These include insecticidal soaps, horticultural oils, and neem oil, which disrupt the insect’s protective outer layer or cause suffocation.
Thorough application is necessary because these products have little residual activity once they dry, requiring precise coverage of the nymphs themselves. Repeated applications are often needed throughout the season as new nymphs hatch or migrate into the treated area. Always follow the specific instructions on the product label, as some oils can damage plant foliage, particularly in hot, direct sunlight.
Stronger contact insecticides containing natural pyrethrins can be used as spot treatments on clustered nymphs. While effective, these compounds are non-selective and can harm beneficial insects, so they should be used sparingly and only when directly targeting the pest. Some home remedies, such as rubbing alcohol or vinegar sprays, will kill nymphs upon contact, but care must be taken, as these liquids can cause phytotoxicity, or burn the leaves of desirable plants.
Preventing Future Infestations by Destroying Egg Masses
The most proactive step in preventing next year’s infestation is destroying the Spotted Lanternfly’s egg masses, which are laid in the late fall and survive the winter. Each egg mass contains an average of 30 to 50 eggs, making their removal a significant population control measure. The masses are typically about an inch long and resemble a smear of dried, grayish-brown mud or putty.
Females lay their eggs on nearly any smooth, hard outdoor surface, including:
- Tree trunks
- Rocks
- Lawn furniture
- Metal equipment
- Vehicles
To destroy a mass, use a tool like a putty knife or plastic card to scrape the eggs off the surface. The scraped material must then be thoroughly destroyed to ensure the eggs cannot hatch.
The most reliable destruction method is to scrape the egg masses directly into a plastic bag or container filled with a liquid solution, such as rubbing alcohol or hand sanitizer. This soaking process kills the eggs more certainly than simply crushing them. Disposal is completed by sealing the bag and discarding it, effectively removing dozens of potential nymphs from the environment.