The Spotted Lanternfly (Lycorma delicatula) is an invasive planthopper native to Asia that poses a threat to agricultural and ornamental plants across the United States. This insect damages host plants by feeding on sap and excreting honeydew, a sticky, sugary substance. Honeydew promotes the growth of sooty mold, which further weakens the plant. Because the adult lanternflies die off as temperatures drop, the overwintering egg mass stage represents the most manageable point in the pest’s annual cycle.
Timing of Egg Deposition
The egg-laying period begins in early fall, usually starting in September, and continues until the first hard frost. This reproductive window often extends into late November or early December in regions with milder autumns. Females can produce up to two egg masses before they perish naturally with the onset of cold weather.
The eggs remain dormant throughout the winter months, protected by their covering. Hatching generally begins the following spring, often around late April or early May, when the nymphs emerge to begin their feeding cycle.
Identifying the Egg Masses
A single egg mass is an oval structure, typically measuring about one inch long, that houses 30 to 50 eggs. When freshly laid, the mass is covered with a creamy-white, putty-like substance that appears shiny and wet. This covering quickly changes color, turning pinkish-gray and then eventually a dull, grayish-brown as it dries and hardens.
Older egg masses often resemble a smear of dried mud or cracked putty, which camouflages them against tree bark and other surfaces. If the protective coating erodes, the internal structure becomes visible, revealing the brown, seed-like eggs arranged in neat, segmented rows.
Common Egg Laying Locations
Female Spotted Lanternflies lay their eggs on a wide variety of hard outdoor surfaces, a behavior that allows for easy transport to new areas. They favor flat, smooth surfaces, often choosing the bark of host trees like the Tree of Heaven or certain maples, but they also use non-plant materials. The masses are frequently deposited on objects that are regularly moved by people, which contributes to the pest’s spread.
Common deposition sites include:
- Outdoor furniture
- Stone, brick, grills, and metal equipment
- Vehicles, including cars, trailers, and recreational vehicles (RVs), which facilitate long-distance travel
The insects often lay their eggs in inconspicuous or protected locations, such as the underside of branches, ledges, or inside vehicle wheel wells.
Eradication and Prevention
The period between late fall and early spring is the most effective time to search for and destroy egg masses before they hatch. Once located, the recommended method for destruction is to scrape the mass off the surface using a hard, flat object, such as a plastic card, putty knife, or paint scraper. This ensures the entire mass is removed.
Simply scraping the masses onto the ground is insufficient, as the eggs may still survive. The most reliable destruction method involves scraping the mass directly into a plastic bag or container filled with a liquid solution of rubbing alcohol or hand sanitizer (at least 60% alcohol). Alternatively, the mass can be scraped off, sealed in a double plastic bag, and then firmly crushed to ensure complete destruction.