The Spotted Lanternfly, Lycorma delicatula, is an invasive planthopper first identified in the United States in 2014. This insect poses a significant threat to agriculture and natural ecosystems by feeding on over 70 plant species, including grapevines, fruit trees, and various hardwoods. Infestations lead to weakened plants, reduced crop yields, and the promotion of sooty mold growth from the insect’s sugary excrement, known as honeydew. Controlling this destructive pest requires a sustained, year-round strategy that targets the insect across all its life stages, as they are highly mobile and reproduce rapidly.
Immediate Physical Elimination
Direct physical removal offers the most immediate way to reduce localized populations of both nymphs and adults. Simply crushing the insects underfoot is an effective and readily available method, especially when dealing with smaller clusters or individual sightings on low-lying vegetation. While straightforward, this manual technique is most practical for small-scale encounters and is often insufficient for controlling widespread infestations.
For larger groups, particularly those situated on smooth surfaces or high on structures, a handheld or shop vacuum can provide a contained method of collection. Once collected, the vacuum’s contents must be immediately sealed and destroyed, often by freezing the bag for a minimum of 48 hours to ensure the insects are killed. A spray of water mixed with dish soap can also be used for direct knockdown of the insects. This soap solution works on contact by coating the insect’s body and suffocating it, but it requires direct application and has no residual impact.
Interrupting the Life Cycle Through Egg Mass Destruction
Targeting the egg masses during the dormant season, which typically runs from late fall through early spring, represents a highly effective preventative measure. Each mass contains 30 to 50 eggs, and a single female can lay at least two masses, making their destruction an important step in reducing the next generation. The masses are frequently deposited on smooth surfaces, including the trunks of trees, outdoor furniture, stone walls, vehicles, and metal objects.
The egg mass is often covered with a protective layer of grayish-brown, mud-like material, resembling dried putty. Destruction involves using a stiff, flat tool, such as a credit card or putty knife, to forcefully scrape the mass off the surface. It is important to scrape the material into a sealed container or bag to prevent any eggs from simply falling to the ground and hatching later.
To guarantee mortality, the scraped masses should be immediately immersed in a solution of rubbing alcohol or hand sanitizer, which desiccates and kills the developing embryos. Alternatively, the masses can be smashed with firm pressure, ensuring the individual eggs burst open. Removing accessible egg masses significantly reduces the population that will emerge in the spring, even if some high in the canopy are unreachable.
Non-Chemical Trapping and Containment
Trapping methods capitalize on the lanternfly’s instinct to climb vertical surfaces. Funnel or circle traps are designed to capture the insects as they ascend a tree trunk, diverting them into a container from which they cannot escape. These traps are highly effective because they exploit the predictable behavior of nymphs, which often walk to the trunk to climb back up after being blown out of the canopy.
Another common containment method involves the use of sticky bands wrapped around the circumference of a tree trunk. The bands exploit the mobility of the early-stage nymphs, which are less able to avoid the adhesive surface as they climb. While this method can successfully capture many lanternflies, these sticky barriers pose a substantial risk to non-target wildlife, including small birds and beneficial insects.
To mitigate the hazard, bands should never be deployed without a protective barrier. A guard of vinyl mesh netting or a wire cage must be installed over the sticky surface to prevent larger animals from making direct contact with the adhesive. Regular inspection of all traps is necessary, at least once a week, to remove trapped lanternflies and to quickly free any accidentally caught beneficial organisms before they succumb.
Utilizing Targeted Insecticide Treatments
When infestations are widespread or populations are too dense for manual controls, chemical treatments become a necessary component of the management strategy. These treatments are generally categorized into contact sprays and systemic applications based on their mechanism of action. Contact sprays are designed for immediate knockdown of visible adult and nymph populations, killing the insect when the chemical physically contacts its body.
Insecticidal soaps or products containing natural pyrethrins are common contact agents for localized outbreaks. These sprays are best used as spot treatments for clusters of nymphs or adults found on trunks, branches, or foliage. Because lanternflies are highly mobile, they will likely move from untreated areas into treated areas after the contact spray wears off, meaning repeated applications may be required.
For persistent or large-scale infestations, systemic insecticides offer long-lasting control by making the entire plant toxic to the feeding insect. Compounds like dinotefuran or imidacloprid can be applied as soil drenches, bark sprays, or trunk injections, allowing the plant to absorb and distribute the chemical. Properly applied systemic treatments can provide months of control by continuing to kill adults as they arrive and feed on the plant.
Systemic applications are typically recommended to target the adult stage, and they should only be applied after the tree has finished flowering to protect pollinators that visit the blooms for nectar. Neonicotinoid systemic insecticides have been associated with potential harm to beneficial insects, so their use should be limited to highly infested, high-value plants. Consulting with a certified arborist or a local extension office is strongly recommended before using systemic chemicals to ensure the application is targeted and to minimize environmental impact.