Spotted Lanternfly

SLF adults lay masses of 30 or more eggs on surfaces ranging from tree trunks to patio furniture, so the public should check trees and surfaces like rocks, metal, outdoor furniture, and fencing for the masses, which are typically 1.5 inches long, greyish brown in color, and resemble clay. They can be found on surfaces anywhere from an inch above the ground to 7-8 feet high. 

After finding an SLF egg mass, scrape the entire egg mass, using a credit card, paint scraper, or other flat, sturdy tool, into a bottle with rubbing alcohol or hand sanitizer, or crush them directly.

Squash insects when you see them. Use Circle Traps on or near affected trees to trap spotted lanternfly as they climb up trees (Penn State Extension DIY Trap Guide). A vacuum and an extension cord can also help remove clusters of insects from trees or surfaces. DIY mixes of soap, water and oil can be effective as an at-home sprayable solution. Over-the-counter garden insecticides, readily found at garden centers or hardware stores, like Neem Oil and other insecticidal soaps can also be effective.

As spotted lanternflies feed, they excrete a sugar-rich substance known as honeydew. Nuisance insects such as wasps and ants may be attracted to accumulations of oozing sap and honeydew. A build-up of honeydew may also become colonized by sooty mold fungi, which can act as a photosynthesis barrier.

Warm, soapy water (mild dish soap works well) and a soft brush or sponge can help scrub mold away. On cars and outdoor equipment, scrub with a similar solution or a gentle cleaner and water. Avoid strong chemicals that could damage paint or finishes. 

For plants and shrubs in a garden, for example, spray leaves with water from a garden hose to wash off buildup. For delicate plants, use a gentle spray setting to avoid damage. Early monitoring and action are key when managing honeydew in a garden.

Although they can fly distances on their own, Spotted Lanternfly are excellent hitchhikers and mainly spread through human movement. 

Their inconspicuous egg masses can be laid on pallets, vehicles, and other goods. It’s important to check your vehicles and outdoor equipment (grills, outdoor furniture, landscaping supplies, mowers, etc.) before traveling to and from Rhode Island, and scrape off any egg masses.

Checking vehicles, trailers, campers, and outdoor items before moving them within or out of state is crucial to reducing the spread. Do not move firewood or plant material from infested areas.

SLF prefers Tree of Heaven (Ailanthus altissima). If you have this tree on your property, consider removing it. In some cases, licensed professionals can treat selected “trap trees” so removal is not always recommended, as this can cause SLF populations to migrate to other host trees on your property and be more difficult to locate and manage.

Insecticides applications are usually not necessary for homeowners. If you grow grapes, fruit trees, or other valuable plants and SLF is causing damage, consult a licensed arborist or pest control professional for potential insecticide treatment. Be aware of flowering plants nearby to the proposed treatment area, as insecticides can kill pollinators, who are crucial to both the environment and agriculture.

There are many factors to consider before deciding to use an insecticide to kill SLF, including:

1. the number of SLF present,
2. whether they are on a preferred host plant where they are likely to remain or on a plant they will move away from after a shorter visit,
3. the size and health of the plant,
4. the presence or absence of preferred host plants in the landscape,
5. and the life stage of SLF present.