The spotted lanternfly (SLF), an invasive planthopper from Asia, has rapidly spread across the United States since its initial detection in Pennsylvania in 2014. This insect is distinct with its gray forewings marked by black spots and red hindwings that become visible when it spreads them. Their increasing visibility has prompted many questions from the public, particularly regarding their potential danger to humans.
Are They Harmful to Humans?
Spotted lanternflies are not poisonous or venomous to humans. They do not possess stingers and their mouthparts are designed for piercing plants to feed on sap, which means they are not capable of biting or penetrating human skin. There is no evidence to suggest that spotted lanternflies carry diseases transmissible to humans or pets. While some social media claims have suggested toxicity to pets, current research does not support these claims. Therefore, common fears about direct physical harm are misconceptions.
Understanding Their Impact
The primary concern with spotted lanternflies is their impact as an invasive species on plants and agriculture. They feed on the sap (phloem) of over 70 different plant species, including trees, vines, and various crops. This feeding weakens plants, leading to symptoms such as oozing sap, wilting, leaf curling, and dieback, which can ultimately stress the plant and potentially lead to its death, especially in susceptible species like grapevines.
A significant consequence of their feeding is the excretion of a sugary substance called “honeydew.” This honeydew accumulates on plants and surfaces below, attracting other insects like wasps and ants. The honeydew also promotes the growth of black sooty mold, which can cover leaves, inhibit photosynthesis, and reduce crop marketability. This combination of feeding damage and mold growth creates both ecological and economic problems for agricultural industries, particularly vineyards and orchards.
Safe Interaction and Reporting
While they do not pose a direct threat, controlling their population is important due to their destructive impact on plants. If encountered, physically dispatching them by stepping on or crushing them helps reduce their numbers. Reporting sightings to local agricultural departments or extension offices is important for tracking and managing the invasive population. This data helps authorities monitor their spread and implement control measures. When traveling from infested areas, inspect vehicles and outdoor items for adult lanternflies or their egg masses, as this insect is known to hitchhike, which contributes significantly to its rapid spread.