The Spotted Lanternfly (SLF) is an invasive insect that poses a significant threat to agricultural crops and hardwood trees. Controlling the spread of this pest depends on interrupting its life cycle before the nymphs hatch in the spring. Finding and destroying the egg masses laid by females in the fall and winter is a highly effective way to reduce the population. Recognizing these masses and knowing where to search for them is the first line of defense.
The Appearance of the Protective Covering
A Spotted Lanternfly egg mass is approximately one inch long and three-quarters of an inch wide, typically containing between 30 and 50 eggs arranged in neat rows. The female covers these eggs with a thick, waxy secretion that acts as a protective layer, shielding them from the elements over the winter months. When freshly laid, this covering is soft, putty-like, and often appears white or a pale pinkish-brown color.
As the egg mass ages and weathers, the waxy coating dries out and changes appearance. It eventually hardens into a substance that looks like a grayish-brown smear of cracked mud or cement. The camouflage is so effective that the mass can be easily mistaken for a natural discoloration on tree bark or a smudge of dirt. Individual eggs within the mass are usually only visible if the protective covering has deteriorated or been partially scraped away.
Common Surfaces for Egg Laying
Spotted Lanternflies deposit masses on virtually any smooth or rough outdoor surface, seeking areas that offer protection from wind and harsh weather, often choosing the undersides of horizontal surfaces. This lack of selectivity contributes to the rapid, accidental spread of the pest, as masses can be laid on movable objects.
Natural surfaces to check include the trunks and branches of trees, especially the Tree of Heaven, as well as stones and large rocks. A thorough search must also extend to human-made structures, which are frequently overlooked. Common sites include metal railings, brick walls, outdoor furniture, grills, and wooden decks. It is important to inspect vehicles, trailers, and outdoor equipment that may be moved between locations, as the egg masses can easily hitchhike to new areas.
Safe Removal and Destruction Methods
Once a Spotted Lanternfly egg mass has been identified, it must be destroyed. Simply scraping the mass off the surface and letting the eggs fall to the ground is not effective. The preferred removal technique involves using a rigid, flat-edged tool, such as a credit card, putty knife, or paint scraper, to dislodge the mass.
After scraping, the eggs must be immediately destroyed. A highly effective method is to scrape the entire mass into a sealed plastic bag or container filled with rubbing alcohol or hand sanitizer, which kills the eggs upon contact. Alternatively, if a container is not available, the eggs should be thoroughly crushed on the surface after being scraped off. Applying pressure until a popping or squishing sound is heard confirms the eggs have been ruptured.