The spotted lanternfly (Lycorma delicatula) is an invasive insect from Asia that has become a significant concern in North America. It was first identified in the United States in Pennsylvania in 2014, likely arriving as egg masses on a stone shipment. Since its initial detection, it has rapidly spread across numerous Northeastern states, posing a new challenge for agriculture and ecosystems.
Are They a Threat to People and Pets?
Spotted lanternflies do not pose a direct danger to humans or household pets. These insects do not bite, sting, or carry diseases harmful to people or animals. Their mouthparts are designed for piercing plant tissue to feed on sap, not for penetrating human or animal skin.
While not venomous or poisonous, pets ingesting them may experience mild, temporary symptoms like an upset stomach, drooling, or loss of appetite. There is no evidence to suggest eating these insects causes severe reactions. The sticky, sugary waste they excrete, known as honeydew, also poses no direct health risk to humans or animals, though it can be a nuisance by coating surfaces and promoting harmless sooty mold growth.
Their Impact on Plants and Agriculture
While not dangerous to humans, spotted lanternflies are a significant threat to plants and agriculture. They feed by extracting sap from plant stems and trunks. This can weaken plants, reduce vigor, and sometimes lead to their death.
Spotted lanternflies infest a wide variety of plants, with over 70 to 173 host species. Economically important crops like grapevines, fruit trees (apple, peach), hops, and hardwood trees (maple, black walnut, willow) are particularly vulnerable. Their feeding can cause reduced crop yields, sometimes as high as 90% in vineyards, and diminished plant health, including loss of winter hardiness and reduced flowering. The honeydew they excrete fosters black sooty mold growth, which covers leaves, blocks photosynthesis, and further stresses plants.
Identifying and Reporting Spotted Lanternflies
Recognizing spotted lanternflies at different stages is important for managing their spread. They have three main life stages: egg masses, nymphs, and adults. Egg masses, laid in fall, contain 30-50 eggs and are covered with a grayish, mud-like substance, often found on trees, vehicles, or outdoor furniture.
Nymphs undergo several molts. Early nymphs (first to third instars) are small, black with white spots and are strong jumpers. The final nymph stage (fourth instar) becomes bright red with black stripes and white spots. Adult spotted lanternflies are about one inch long, featuring grey forewings with black spots and striking red hind wings, visible when their wings are open.
Reporting sightings is crucial for tracking their distribution and implementing control measures. Most local agricultural departments or extension offices provide online reporting tools or hotlines. If encountered, it is recommended to kill the insect by crushing it or, if an egg mass, scraping it into a bag containing alcohol or hand sanitizer. Practicing “Look Before You Leave” by inspecting vehicles and outdoor items can help prevent accidental transportation of these pests to new areas.