The spotted lanternfly (Lycorma delicatula) is an invasive insect that has become a significant concern in various regions. This planthopper, recognizable by its distinct appearance, does not directly threaten humans or pets through bites or stings. However, its presence poses a serious ecological and economic risk to agricultural industries and natural ecosystems.
Harms to Humans and Pets
There is no scientific evidence suggesting they transmit diseases to humans or pets. Ingesting many spotted lanternflies may cause mild gastrointestinal upset in pets, such as vomiting or diarrhea. Veterinarians have observed temporary stomach issues, drooling, or loss of appetite in pets that consume them.
The primary nuisance to humans and pets stems from the “honeydew” these insects excrete. This sticky substance accumulates on outdoor surfaces, attracting wasps and ants, and promoting black sooty mold growth on plants and objects.
Threat to Plants and Ecosystems
Its destructive impact on plants and ecosystems is significant. These insects feed on the sap (phloem) of a wide variety of plants, weakening them and causing significant damage or death. Their piercing wounds extract sap, leading to stress, stunted growth, and reduced crop yields.
Spotted lanternflies feed on over 70 plant species, including economically important crops and trees. Grapes, hops, and fruit trees like apples, peaches, cherries are particularly vulnerable. Feeding results in oozing sap, wilting, defoliation, and dieback, especially in grapevines. Their preferred host, the invasive tree of heaven (Ailanthus altissima), is heavily infested, but they also target maples, walnuts, birches, and willows. Beyond direct feeding damage, honeydew promotes sooty mold growth, which coats plant surfaces, interferes with photosynthesis, and reduces aesthetic and market value.
What to Do If You Encounter Them
Public action is key to managing the spread of spotted lanternflies. Adults are one inch long, with tan forewings speckled with black spots and striking red hindwings visible when spread. Nymphs are smaller and wingless, starting black with white spots, then developing red coloration.
If you encounter a spotted lanternfly, you should “squish it” to prevent further spread. Report sightings to local agricultural departments or extension offices, via online tools, to help track populations and allocate resources. In the fall, females lay egg masses, containing 30-50 eggs, on any smooth outdoor surface, including trees, stones, vehicles, and outdoor furniture. They are about 1.5 inches long and resemble gray, waxy mud. Scraping these egg masses into a sealed bag with rubbing alcohol or hand sanitizer, or simply crushing them, destroys them and prevents hatching.
Origin and Spread of Spotted Lanternflies
The spotted lanternfly is native to Asia, from China, India, and Vietnam. This invasive species was first detected in the United States in Berks County, Pennsylvania, in September 2014, likely arriving on imported goods. Since then, it has rapidly expanded its range across multiple Northeastern U.S. states, including New York, New Jersey, Delaware, Maryland, and Virginia.
Their spread is facilitated by human activity. Spotted lanternflies are adept hitchhikers, with adults and egg masses often transported on vehicles, outdoor equipment, firewood, and nursery stock. Egg masses are laid on any hard surface, making them hard to detect and easily moved. This rapid, human-assisted dispersal highlights the need for public awareness and vigilance when traveling from infested areas.