The spotted lanternfly, an invasive insect, poses a significant threat to agriculture and natural ecosystems. This planthopper feeds on the sap of numerous plants, including economically important crops like grapes, hops, and fruit trees, as well as hardwood trees. Understanding its life cycle, particularly its egg-laying habits, is fundamental for effective management efforts. Knowing when, where, and how these insects lay their eggs provides an important window for intervention, helping to reduce their populations and mitigate their damaging impact on plant health.
The Egg-Laying Season
Spotted lanternflies typically begin laying eggs in late summer, continuing through the fall and into early winter. This period generally spans from September or October until the first hard frost, often in November or December, when cold temperatures kill adults.
Each female lays one or two egg masses, with approximately 30 to 60 eggs per mass. These masses endure colder months, allowing the next generation to survive the winter. Eggs remain dormant through the winter (diapause), hatching as temperatures warm. Hatching typically occurs in the spring, from May to June, when nymphs emerge.
Identifying Spotted Lanternfly Egg Masses
Recognizing spotted lanternfly egg masses is an important step in control. Freshly laid egg masses often appear as a creamy-white or grayish, wet, putty-like substance. This protective coating covers the eggs. As the egg mass dries, it becomes a dull grayish-brown or tan, resembling cracked mud or cement.
The entire egg mass is typically one to one and a half inches long. Sometimes, the protective covering wears away, revealing the individual, seed-like eggs beneath. These visual cues are important for distinguishing spotted lanternfly egg masses from other insect egg masses or natural marks on surfaces.
Typical Egg-Laying Sites
Spotted lanternflies are not particularly selective about egg-laying sites, often choosing a wide variety of smooth, hard surfaces. Common sites include the bark of trees (especially Tree of Heaven, maples, willows), rocks, stones, and outdoor furniture.
They also use man-made objects like vehicles, trailers, grills, fences, and various types of outdoor equipment. This adaptability and tendency to lay eggs on mobile objects contribute to their rapid spread, as egg masses can easily hitchhike on transported items. Inspecting any outdoor items or vehicles before moving them, especially across regions, is important.
Managing Egg Masses
Destroying spotted lanternfly egg masses before hatching effectively reduces future populations. This preventative measure prevents dozens of nymphs from emerging in the spring. Once an egg mass is located, it can be scraped off the surface using a stiff tool like a credit card, putty knife, or butter knife.
Apply firm pressure during scraping to ensure all eggs are crushed. After removal, dispose of scraped eggs in a sealed plastic bag containing rubbing alcohol or hand sanitizer to kill them. Alternatively, thoroughly smash the eggs after scraping them off. This direct action helps control the pest’s spread.