Lantern bugs, most commonly the spotted lanternfly, are not harmful to people or pets. They don’t bite, sting, or attack humans, animals, or livestock. Their real damage is to plants, trees, and agriculture, where they can cause serious and costly destruction.
No Risk of Bites or Stings
Spotted lanternflies have piercing-sucking mouthparts that work like a tiny straw, designed to puncture plant tissue and extract sap. These mouthparts are not capable of penetrating human or animal skin. You can handle them, squish them, or brush them off without any risk of being bitten or stung.
There’s also no evidence that they carry toxins. Some social media posts have claimed the insects are toxic to dogs and cats, but testing has found no support for this. Specifically, spotted lanternflies do not contain cantharidin, a harmful substance found in certain other insects like blister beetles. That said, any insect with tough wings and a hard exoskeleton can be difficult for a pet to digest in large quantities, so it’s worth keeping dogs from snacking on them in bulk.
The Real Harm: Plant and Tree Damage
Where lantern bugs cause genuine problems is in your yard, your garden, and especially on farms. They feed by drilling into plants and drinking large quantities of sugary sap to extract the nitrogen and amino acids they need. Because the sap is mostly sugar water, they expel huge amounts of excess liquid called honeydew. This sticky waste coats leaves, branches, outdoor furniture, decks, and cars beneath infested trees.
Left to accumulate, honeydew becomes a growth medium for sooty mold, a dark fungal coating that blackens surfaces. On leaves, sooty mold blocks sunlight and reduces the plant’s ability to photosynthesize. On fruit like grapes and apples, it makes crops unsellable even though the insects never feed on the fruit directly. The honeydew also ferments and produces a noticeable odor that attracts bees and wasps, creating a secondary stinging risk around heavily infested plants.
In neighborhoods with large infestations, swarms feeding on shade trees can make parks and backyards genuinely unpleasant. Sticky surfaces, dark mold stains, and clouds of attracted wasps can restrict how much you enjoy your own outdoor space.
Grapevines and Hardwoods Hit Hardest
Spotted lanternflies feed on more than 70 plant species, but grapevines are among the most vulnerable. The insects weaken vines by draining sap, reducing both the quality and quantity of grapes produced. Cornell University researchers studied the potential impact on New York’s grape industry and found that losses could reach $1.5 million in the first year of infestation, $4 million in the second year, and $8.8 million by the third year, just in two key growing regions. New York is the third-largest wine producer in the country, with nearly 470 wineries and 900 vineyards generating roughly $15 billion in economic activity in 2022.
Hardwood trees, particularly the tree of heaven (an invasive species the lanternfly prefers), are also heavily targeted. But the insects readily move to maples, oaks, walnut trees, and fruit trees when their preferred host isn’t available. Young trees and stressed plants are especially vulnerable to repeated feeding pressure over a season.
How They Spread
The spotted lanternfly was first detected in the United States in 2014 in Berks County, Pennsylvania, in a wooded area full of tree of heaven. Despite quarantine efforts and eradication attempts, it proved difficult to contain. The insects are excellent hitchhikers: they lay flat, gray egg masses on nearly any outdoor surface, including vehicles, shipping containers, firewood, and patio furniture. This means they travel long distances by riding along with human activity rather than flying.
By 2020, established populations had appeared in New York City and Ithaca, New York. By 2021, infestations had expanded across Long Island, the lower Hudson Valley, and the Binghamton area, with new detections in Massachusetts and Indiana. The insect now has confirmed populations or sightings across multiple eastern states, and agricultural quarantine zones remain in effect in several regions to slow the spread.
What You Can Do About Them
If you spot lanternflies on your property, you can kill them without hesitation. They’re an invasive species, and most affected states actively encourage residents to stomp adults and scrape off egg masses when they find them. Egg masses look like patches of dried mud, roughly an inch long, and appear on tree trunks, fences, stone walls, and outdoor equipment from late fall through spring.
For trees and plants showing signs of heavy feeding, sticky honeydew, or sooty mold buildup, a strong spray of water can wash away honeydew before mold establishes. Circle traps wrapped around tree trunks can catch nymphs as they climb. If you’re moving outdoor items out of a quarantine zone, check for egg masses on any smooth surface, including the underside of trailers, wheel wells, and camping gear.