Spotted lanternfly (SLF), Lycorma delicatula, is an invasive planthopper, native to Asia, that was first detected in 2014 in southeastern Pennsylvania. It feeds voraciously on many plants, including economically important crops like fruit trees, grapevines, hops, hardwoods, and ornamentals. If you think you have SLF, do not panic! First, make sure the insect you are seeing is the spotted lanternfly. Second, learn about its life cycle and habits. Third, determine what plants it is infesting and what it is not. Fourth, employ management strategies at the proper time of the year.
Identification and Life Cycle
There is one generation of SLF per year. The eggs are laid in the fall and hatch in the spring. Egg masses are laid on hard surfaces (trees, decks, houses, outdoor equipment, rocks, etc.) and protected with a mud-like covering. Each egg mass contains 30–50 eggs. After hatching and before reaching adulthood, SLF goes through four nymph stages. Nymphs are small (⅛ to ½ inch) and can be hard to find. The first three stages (instars) are all black with white spots, and the last instar is red with white dots and black stripes (Figure 1). SLF adults emerge in July and are active until winter. This is the most obvious and easily detectable stage because they are large (~1 inch) and highly mobile. Adults have black bodies with brightly colored wings. Only the adults can fly. Because SLF adults jump more than fly, their wings often remain closed. SLF wings are gray with black spots, and the tips of the wings are black with gray veins.
- SLF is a destructive invasive pest, threatening agricultural, timber, and ornamental industries, and the plants in your backyard.
- SLF is currently under quarantine in 14 counties in Pennsylvania.
- SLF does not bite or sting.
- Stop the spread of SLF by checking your car and any outdoor equipment (grills, mowers, firewood, etc.) when going in and out of the quarantine zone.
- Manage SLF on your property by scraping eggs, banding trees, removing the favored host (tree-of-heaven), and using chemical control when appropriate.
Figure 1. The life stages of SLF, including an egg mass on a tree.
A. Egg Mass. Found September-June. Photo Credit: E. Swackhamer
B. Early nymph (actual size = 1/8″) Found late April-July. Photo credit: PA Department of Agriculture
C. Late nymph (actual size = 1/2″) Found July-September. Photo credit: PA Department of Agriculture
D. Adult, wings closed (Actual size = 1 inch) Founds July-December. Photo credit: PA Department of Agriculture
E. Adult, wings open. Photo credit: PA Department of Agriculture
Current Distribution and Reporting
An SLF quarantine is currently in effect for 14 counties in Pennsylvania (Figure 2). If you find a spotted lanternfly, kill it and report it immediately with our online reporting system or by calling 1-888-4BAD-FLY (1-888-422-3359).
Figure 2. The distribution as of March 18, 2019, of SLF in Pennsylvania, indicated in blue. Check the Pennsylvania Department of Agriculture’s website for updated distribution information.
SLF is capable of causing serious damage to its host, including oozing sap from the trees, wilting, leaf curling, and tree dieback. SLF feeds using a piercing-sucking mouthpart tapped into the plant like a straw. When SLF feeds, it also excretes honeydew, or sugary water. This creates a sugary surface on and around plants that encourages the growth of black sooty mold. This mold is harmless to people but can cause damage to the plant. If you see black sooty mold or sticky areas on a plant or tree, it may be infested by SLF, but it could also be aphids, leafhoppers, planthoppers, or scale insects. Therefore, it is important to identify the cause of the mold, as control measures may differ for pests other than SLF. There is no way to prevent SLF from moving onto your property. Be aware that SLF is very mobile and management actions must be continuous to keep them controlled.
Stop the Spread
When you travel in and out of the quarantine zone, check your car and outdoor equipment (grills, outdoor furniture, landscaping supplies, mowe