The spotted lanternfly (Lycorma delicatula) is an invasive insect that poses a threat to agricultural crops and plants. First identified in the United States in Pennsylvania in 2014, this pest has since spread across the Northeastern region. Early detection and management of its egg masses are important for controlling its population and limiting further dispersal. Egg masses are the primary way this insect spreads to new areas, often by hitchhiking on transported goods.
Visual Characteristics of Egg Masses
Spotted lanternfly egg masses typically appear as an irregular splotch or smear, often resembling dried mud or clay. When freshly laid, they are creamy-white or light gray with a putty-like texture. As these masses dry and age, their color changes to pinkish-gray, then to a darker tan or dull brown, often developing a cracked appearance.
Each egg mass contains approximately 30 to 50 individual eggs, laid in rows and covered by the female. A complete egg mass is about 1 inch long by three-quarters of an inch wide, though some can be up to 1.5 inches long. Older or weathered egg masses may lose their protective covering, revealing the individual, seed-like eggs underneath.
Common Locations and Timing of Egg Laying
Spotted lanternflies lay their eggs from late September through November, or until the first hard freeze. These egg masses survive winter, remaining viable until they hatch in the spring. They can be observed on various surfaces from September through June.
Females deposit their egg masses on nearly any stable outdoor surface. Common locations include tree bark, particularly the tree of heaven, as well as rocks, stones, and outdoor furniture like chairs and patio tables. They also lay eggs on vehicles such as cars, RVs, and trailers, along with firewood, grills, equipment, fences, and posts. Egg masses are frequently found in protected spots or higher up on trees.
Distinguishing from Similar Egg Masses
Spotted lanternfly egg masses can be mistaken for other insect egg masses or natural elements like lichen. Praying mantis egg cases are often light tan, foamy, and are more uniform in shape, resembling dried styrofoam. They lack the mud-like covering characteristic of spotted lanternfly masses.
Spongy moth (formerly gypsy moth) egg masses are typically lighter in color and have a fuzzy or fibrous texture, appearing similar to a patch of felt. Spongy moth eggs are more spherical than those of the spotted lanternfly. While found on trees and rocks, they are less commonly seen on household items.
Mud dauber nests are typically tube-shaped or form small, cylindrical lumps, differing from the flattened, irregular appearance of lanternfly masses. Wheel bug eggs are dark and barrel-shaped, arranged in a neat hexagonal pattern, and lack any covering.
What Happens After Eggs Hatch
Spotted lanternfly eggs typically begin to hatch in late April or early May, with hatching continuing through June. From these eggs emerge wingless nymphs. The first instar nymphs are small, measuring about 1/8 to 1/4 inch in length. They are characterized by their black coloration with distinct bright white spots.
These nymphs are capable of strong jumps and are active. As they progress through several developmental stages, known as instars, they gradually increase in size. The fourth instar nymph undergoes a noticeable change in appearance, developing red patches in addition to its white spots and black markings, growing up to 1/2 or 3/4 inch long. These nymphs actively feed and relocate to new host plants as they mature.