The Spotted Lanternfly (Lycorma delicatula), is a striking and highly visible invasive planthopper currently spreading across North America. This insect, which is not a fly but a type of true bug, presents a significant threat to agricultural industries and homeowner landscapes in infested areas. Its rapid spread and tendency to feed in large, concentrated groups causes concern for fruit growers, vineyard owners, and those managing high-value trees. The species’ ability to hitchhike on various materials necessitates human intervention to slow its expansion into new regions.
Identification and Life Cycle
The Spotted Lanternfly undergoes a single generation annually, featuring four nymphal stages, an adult stage, and an overwintering egg stage.
The earliest nymphs hatch in late spring, appearing black with bright white spots and measuring about one-eighth of an inch long. Through the second and third stages, they retain this coloration, growing to about a quarter-inch. The fourth and final nymph stage, visible from July through September, takes on a bright red base color, still covered with black stripes and white spots. These young insects are strong jumpers but lack wings.
Adults begin to emerge in mid-to-late summer and remain active until the first hard frost, typically growing to about one inch in length. At rest, the adult insect’s most recognizable feature is its forewings, which are a dull, grayish-tan color covered in distinct black spots. When startled or in flight, the insect reveals its hindwings, which possess a pattern of scarlet red and black patches, separated by a white band.
Females lay egg masses in the fall (September until the first killing freeze), with each mass containing 30 to 50 eggs. These masses are generally one inch long and are covered with a protective, putty-like substance that is initially light gray or white. As the covering dries and ages over the winter, it turns a light tan and cracks, often resembling a smear of dried mud on the surface. Egg masses can be found on nearly any smooth, outdoor surface, including tree bark, rocks, lawn furniture, vehicles, and equipment.
Origin and Current Spread
The Spotted Lanternfly is native to Asia, specifically China, Vietnam, and India, where natural predators help keep its populations in check. The pest was first discovered in the United States in Berks County, Pennsylvania, in 2014, likely arriving on goods shipped from overseas. Since then, it has spread rapidly through several eastern states, establishing itself in the mid-Atlantic and Northeast.
The primary method of long-distance spread is through human assistance, as the insect is a notorious hitchhiker. Adults and nymphs will cling to vehicles, while the egg masses are inadvertently transported on firewood, outdoor equipment, recreational vehicles, and construction materials. State and federal agencies have implemented quarantine zones to slow this spread, which regulate the movement of materials that may harbor the insect. Individuals and businesses traveling from these areas must check their belongings and vehicles to avoid unknowingly moving the pest to new locations.
The Damage Caused
The harm caused by the Spotted Lanternfly is directly related to its feeding mechanism as a planthopper. Using piercing-sucking mouthparts, the insect extracts large volumes of sugary sap directly from the phloem of host plants. This constant sap loss severely stresses the plant, leading to weakened health, reduced vigor, and increased vulnerability to disease. While larger, established trees may withstand heavy feeding, high-value crops like grapevines and fruit trees can suffer significant yield reduction or even plant death.
The second major consequence of this feeding is the production of a sugary waste product known as honeydew. Spotted Lanternflies excrete this sticky substance in copious amounts, showering the plant and anything beneath it (decks, cars, and understory plants). This honeydew then becomes a perfect medium for the growth of a black, superficial fungus called sooty mold. The sooty mold does not directly infect the plant tissue, but it coats the leaves, physically blocking the sunlight required for photosynthesis, further weakening the host. The insect shows a strong preference for the invasive Ailanthus altissima, or Tree of Heaven, which often acts as a host plant that fuels the growth of local populations.
Control and Reporting
Controlling the Spotted Lanternfly requires a cooperative effort from the public, focusing on physical destruction and early detection. The most impactful action citizens can take is the destruction of overwintering egg masses, which are visible and vulnerable from October to May. Egg masses should be scraped off the surface (using a credit card or putty knife) and immediately sealed in a plastic bag or container with rubbing alcohol or hand sanitizer to ensure the eggs are killed.
Mechanical control of the mobile life stages is also highly effective for individual insects. Nymphs and adults should be killed on sight, which can be accomplished by stomping, squishing, or knocking them into a container of soapy water. Trapping can also be utilized, with circle traps being a popular option to capture nymphs as they crawl up tree trunks. If using sticky bands, wrap the band with a protective wire mesh or cage to prevent non-target animals, such as birds or small mammals, from being accidentally trapped.
Reporting sightings is important, particularly if the insect is found outside of currently established infestation areas. Early detection allows agricultural departments to quickly implement containment measures and prevent further spread. Sightings, especially of egg masses or adults, should be documented with a photograph and submitted to the local state Department of Agriculture or Cooperative Extension office.