The spotted lanternfly (Lycorma delicatula) is a highly visible invasive species that originated in Asia. First detected in the United States in 2014, it has since spread rapidly across the eastern regions of North America. Its prevalence often leads to questions about safety, particularly whether this unusual-looking insect poses a direct physical threat to people or pets.
The Truth About Bites and Stings
Spotted lanternflies do not bite, sting, or possess any venom that could harm humans, pets, or livestock. Their mouthparts are designed exclusively for piercing and sucking plant tissue, meaning they are not capable of penetrating human or animal skin. This insect belongs to the order Hemiptera, or “true bugs,” which includes other sap-feeding insects like cicadas and aphids. The species is considered a nuisance pest because of the vast numbers in which they appear, not because of any direct physical danger.
How They Feed and Cause Damage
The spotted lanternfly’s role as a pest stems from its feeding on plants. Both the adult and nymph stages use a specialized, straw-like proboscis to pierce the bark and stems of plants to extract sap from the phloem tissue. This constant sap removal stresses the host plant, potentially leading to branch dieback and weakening the plant’s overall health. Heavy feeding pressure can kill commercially important crops like grapevines.
The insects also excrete large amounts of a sugary liquid waste product known as “honeydew.” This sticky substance can coat anything beneath infested trees, including decks, cars, and understory plants. Honeydew promotes the rapid growth of black sooty mold, a fungus that covers plant leaves and reduces photosynthesis. The combination of sap loss and sooty mold growth makes the spotted lanternfly a threat to agriculture and forested regions, particularly affecting the invasive Tree of Heaven (Ailanthus altissima), grapevines, and certain hardwood trees.
Recognizing the Spotted Lanternfly
Identifying the spotted lanternfly is straightforward due to its distinctive appearance across its life stages. The adult insect is approximately one inch long, featuring gray forewings covered in black spots, with the tips marked by a net-like pattern of black lines. When startled or taking flight, it flashes its hindwings, which are a striking combination of bright red, black, and white bands.
Before reaching adulthood, the insect goes through four nymph stages. The first three nymph stages are black with bright white spots and are strong jumpers, often clustered on new growth of plants. The final nymph stage, known as the fourth instar, changes color dramatically, displaying vivid red patches mixed with the black and white spots before molting into its final adult form.
Strategies for Management and Removal
Effective management focuses on disrupting the life cycle, particularly by targeting the overwintering egg masses. Females lay these masses, each containing 30 to 50 eggs, on nearly any hard outdoor surface, covering them with a gray, mud-like substance for camouflage. Scraping the egg masses off the surface using a plastic card or putty knife and destroying them by sealing them in a bag with hand sanitizer or alcohol is an effective, non-chemical control method.
For controlling nymphs and adults, physical removal remains the most accessible action for the general public, often referred to as the “stomp it” campaign. Simple mechanical traps, such as circle traps, can be wrapped around tree trunks to capture nymphs as they climb. Reporting sightings in new, uninfested areas to local agricultural extension agencies is helpful, as this information is used to track the pest’s spread and coordinate containment efforts.