The spotted lanternfly, Lycorma delicatula, is an invasive insect first identified in the United States in Pennsylvania in 2014. Native to parts of Asia, this planthopper is more closely related to cicadas and aphids than true flies. Adults are approximately one inch long, with gray forewings featuring black spots and a brick-like pattern. Their brightly colored hind wings, red with black spots and white and black bars, become visible when startled or in flight. Younger stages, known as nymphs, are black with white spots, later developing red patches.
Do Spotted Lanternflies Bite Humans?
Spotted lanternflies do not bite or sting humans or pets. They possess piercing-sucking mouthparts, adapted for feeding on plant sap. These mouthparts function like a tiny straw, extracting fluids from plant tissues. Their mouthparts are not capable of penetrating human or animal skin.
How Spotted Lanternflies Feed and Impact Plants
Spotted lanternflies extract sap from the phloem of plants using their straw-like mouthparts. Unlike insects that actively suck, sap flows into their mouthparts due to the natural pressure within the plant. They feed on over 70 to 100 plant species, including economically valuable crops like grapes, hops, peaches, and apples, as well as hardwood trees such as maples, walnuts, and willows. They also frequently feed on the invasive tree-of-heaven, Ailanthus altissima.
As they feed, lanternflies excrete a sticky, sugary liquid called “honeydew.” This honeydew accumulates on surfaces, attracting other insects like bees and wasps. It also promotes the growth of black sooty mold, which covers leaves and stems. Sooty mold inhibits photosynthesis, weakening plant health and, in severe infestations, contributing to plant stress and even death, particularly for grapevines. The presence of spotted lanternflies poses a significant economic threat to agriculture, potentially causing hundreds of millions of dollars in annual losses.
What to Do When You Encounter a Spotted Lanternfly
If you encounter a spotted lanternfly, kill it immediately. They are fast jumpers, so quick action is necessary. In addition to killing adults, destroy any egg masses you find. These masses, appearing as gray or mud-like smears, can be found on hard surfaces like tree trunks, rocks, outdoor furniture, and vehicles. Scrape them off and destroy them by placing them in a sealed bag with hand sanitizer or rubbing alcohol, or by crushing them.
Reporting sightings is important, especially if you are in an area where they are not yet widely established or outside a designated quarantine zone. While some infested regions may no longer require individual reports, reporting helps authorities track the insect’s spread and aids control efforts. To prevent accidental transportation, inspect vehicles and outdoor items before moving them, particularly when traveling from or through infested areas.