Spotted lanternflies are an invasive insect species that have become a growing concern in various regions. These planthoppers have rapidly spread across multiple states since their initial detection in the United States. Their presence raises significant concerns due to their potential to cause extensive harm to agricultural crops and natural ecosystems.
Are They a Threat to People or Pets?
Spotted lanternflies do not pose a direct physical danger to humans or household pets. These insects do not bite, sting, or transmit diseases. Their mouthparts are designed for piercing plant tissues to extract sap, not for biting animals. No confirmed toxins have been found in spotted lanternflies. However, some veterinarians have noted that curious pets who consume them might experience mild symptoms like an upset stomach, temporary drooling, or a loss of appetite.
Impact on Plants and Ecosystems
Spotted lanternflies primarily damage plants through their feeding habits, utilizing piercing-sucking mouthparts to draw out sap from stems and trunks. They feed on a wide array of plants, impacting over 70 different species, including many economically important agricultural crops and native trees. Key agricultural targets include grapevines, hops, and various fruit trees such as apples, peaches, and other stone fruits. Native trees like maples, walnuts, willows, and river birches also suffer from their feeding, alongside the invasive tree of heaven, which is a preferred host.
Their feeding activity can weaken host plants, leading to reduced growth, diminished productivity, and a decline in overall plant health. In vineyards, heavy infestations can result in substantial crop losses, with some growers reporting up to 90% yield reduction or even vine death. As spotted lanternflies feed, they excrete large quantities of a sugary, sticky substance known as “honeydew.” This honeydew then becomes a breeding ground for black sooty mold, which can cover plant surfaces. Sooty mold interferes with photosynthesis, hindering the plant’s ability to produce energy and thrive. The presence of honeydew also attracts other nuisance insects, including ants, wasps, and flies, exacerbating the problem. This widespread damage leads to increased costs for pest management and negative impacts on tourism in affected areas.
Why They Are a Problem
Spotted lanternflies are considered a significant problem because they are an invasive species, originating from China, India, and Vietnam. Their introduction to the United States, first identified in Pennsylvania in 2014, was likely accidental, occurring through international shipments. In their native range, natural predators like parasitic wasps help regulate their populations, but these biological controls are largely absent in invaded regions. This lack of natural enemies allows spotted lanternfly populations to grow unchecked and spread rapidly.
The insects reproduce quickly, with females laying egg masses containing 30 to 50 eggs. These egg masses are often deposited on almost any hard surface, including vehicles, outdoor equipment, and goods. This facilitates their most common mode of spread: “hitchhiking” on cars, trucks, trains, and commercial shipments over long distances. This ability to travel on human-transported items contributes to their rapid expansion into new territories.
What to Do If You See Them
If you encounter spotted lanternflies, immediate action can help manage their spread. Adults and juveniles should be squished to eliminate them. You should also look for and scrape off their egg masses, which are typically visible between September and May. These masses have a mud-like or putty-like appearance, often grey or brown in color.
To destroy egg masses, scrape them into a sealable bag or container filled with rubbing alcohol or hand sanitizer. Alternatively, you can scrape them into a bucket of soapy water. Another method involves scraping the egg masses off the surface and then crushing them underfoot. It is also important to report any sightings of spotted lanternflies to your local agricultural department or extension office. Reporting helps experts track their geographic spread and implement targeted management strategies.