The Spotted Lanternfly, Lycorma delicatula, is an invasive planthopper that has become a concern in regions where it has been introduced. This insect poses a threat to various plants and agricultural industries. Understanding its characteristics and life cycle is important for managing its spread and impact.
Identification and Life Cycle
The Lycorma delicatula undergoes four distinct stages in its annual life cycle, beginning with overwintering eggs. Egg masses are laid in the late fall, appearing as grayish, mud-like smears about 1 to 1.5 inches long and 0.5 to 0.75 inches wide. They are found on trees, outdoor furniture, vehicles, and other hard surfaces. Each mass can contain between 30 and 50 eggs.
Nymphs hatch from these egg masses in the spring, from April to June. The early nymph stages (first through third instars) are small, wingless, and black with white spots, measuring about 0.25 inches long. As they develop, the nymphs transition to a late stage (fourth instar), becoming larger, about 0.5 to 0.75 inches long, and developing red patches alongside their black bodies and white spots. Nymphs are strong jumpers but cannot fly.
Adult spotted lanternflies emerge from July through December, reaching about 1 inch long and 0.5 inches wide at rest. When at rest, their forewings are grayish-brown with black spots and lie tent-like over their bodies, revealing a pinkish hue from the hidden hindwings. When they open their wings, a display of scarlet hindwings with black spots and white bars becomes visible. Adults can fly short distances, but their primary mode of movement is jumping or hitchhiking.
Geographic Origin and Spread
The spotted lanternfly is indigenous to parts of China, India, and Vietnam. It was first detected in the United States in September 2014, specifically in Berks County, Pennsylvania. The insect likely arrived in the country through a shipment of stone from overseas.
Since its initial detection, Lycorma delicatula has rapidly expanded its range across numerous states in the northeastern United States and beyond, including Delaware, Maryland, New Jersey, New York, and Virginia. The primary method of its spread is human-assisted dispersal, as it is an expert “hitchhiker”. Egg masses are laid on a wide variety of outdoor surfaces such as vehicles, trailers, firewood, outdoor furniture, and equipment, allowing them to be transported to new locations.
Impact on Plants and Property
The spotted lanternfly feeds on a wide range of plants, utilizing its piercing-sucking mouthparts to draw sap from stems and trunks. This feeding activity, often by thousands of insects, stresses the host plants, making them more susceptible to disease and other pests. While it feeds on over 70 plant species, its preferred host is the invasive Tree of Heaven (Ailanthus altissima). However, it also poses a threat to economically important agricultural crops such as grapevines, hops, stone fruits (like apples, peaches, and cherries), and various hardwood trees including maples, walnuts, and willows.
A secondary problem associated with spotted lanternfly infestations is the excretion of a sugary waste product known as “honeydew”. This sticky substance accumulates on plants, attracting other insects like wasps and ants. The honeydew promotes the growth of black sooty mold, which can cover plant surfaces, interfering with photosynthesis and reducing plant vigor and fruit yield. Sooty mold also coats outdoor areas, such as decks, patios, and vehicles, making them sticky and difficult to clean.
Management and Reporting Procedures
Controlling the spotted lanternfly requires active public participation. Upon sighting an adult or nymph, it is recommended to “squish it” to destroy the individual insect. While killing individual bugs may not drastically alter population dynamics, it contributes to local reduction efforts.
Removing egg masses is an impactful management strategy, as each mass can contain 30 to 50 eggs. To destroy egg masses, they should be scraped off the surface using a stiff tool like a plastic card or putty knife. The scraped eggs should then be placed into a re-sealable bag or container filled with rubbing alcohol or hand sanitizer. This ensures the eggs are killed and prevents them from hatching. The sealed bag should then be disposed of in the trash.
Reporting spotted lanternfly sightings is an important step in tracking and containing their spread. If an individual encounters a spotted lanternfly, they should take a photo and note the location. This information, along with the date, should then be reported to their state’s Department of Agriculture or local university extension office. These agencies use public reports to monitor infestations, establish quarantine zones, and implement broader control measures to protect agriculture and natural resources.