The spotted lanternfly (Lycorma delicatula) is an insect with distinctive brown forewings, black spots, scarlet hind wings, and a yellow abdomen with black bars. This planthopper causes environmental and economic problems due to its widespread presence and destructive feeding habits. It does not bite or sting humans or pets.
Origin as an Invasive Species
The spotted lanternfly is native to China, India, and Vietnam. It was first detected in North America in Pennsylvania in 2014, likely arriving through international trade or via egg masses on shipping containers and vehicles. In its new habitats, this invasive species lacks natural predators, allowing its populations to grow unchecked and rapidly overwhelm local ecosystems.
Threat to Agriculture
Spotted lanternflies threaten commercial agriculture by feeding on over 70 plant species, including grapevines, fruit trees, and hops. Both nymphs and adults extract sap from plant stems and trunks, weakening plants, reducing yields, and potentially causing death. Heavy infestations on grapevines, for example, can reduce winter hardiness, diminish fruit production, and lead to vine mortality.
Their feeding also excretes “honeydew,” a sticky, sugary substance. This honeydew promotes black sooty mold growth on plants and surfaces. Sooty mold covers leaves, impeding photosynthesis and reducing crop marketability. Honeydew also attracts other insects like ants, bees, and wasps, which can disrupt harvests.
Damage to Natural Environments and Quality of Life
Spotted lanternflies damage native trees and ornamental plants by feeding on their sap. This weakens plants and increases their susceptibility to stressors, diseases, or pests. Their preferred host is the invasive tree of heaven (Ailanthus altissima), but they also impact native trees such as maple, oak, and willow.
Honeydew and sooty mold growth also affect natural environments and residential areas. Honeydew coats outdoor spaces like cars, decks, and patio furniture, making surfaces sticky and slippery. Sooty mold then grows on these surfaces, creating an unsightly black film. The sheer number of spotted lanternflies in infested areas can significantly affect quality of life, making outdoor activities a nuisance due to their constant presence and sticky excretions.
Broader Economic Impact
The spotted lanternfly infestation has significant financial repercussions across various sectors. Agricultural businesses face costs for pest management and control, plus losses from reduced crop yields and damaged produce. A 2019 Pennsylvania study estimated annual economic losses of at least $324 million and 2,800 job losses if the infestation is not contained. Worst-case scenarios project losses increasing to $554 million annually and nearly 5,000 jobs.
Homeowners and government agencies also incur expenses for managing infestations and cleaning honeydew and sooty mold. Property treatment costs can range from hundreds to thousands of dollars. Furthermore, spotted lanternflies could impact property values and tourism in infested regions, potentially leading to other countries refusing agricultural exports due to contamination concerns.