In 2014, swarms of white, red and black speckled bugs showed up around Pennsylvania. Eight years later, sightings of these insects have been reported in over a dozen other states. Spotted lanternflies, native to China and southeast Asia, are a voracious and quickly spreading threat to plants. Now, scientists and local governments are asking people to kill these invasive bugs on sight.
Jaeso Rich, a Spotify employee in New York City, tells the Guardian’s Naaman Zhou that he went out to kill lanternflies on his lunch break. “I didn’t know up until yesterday that they were supposed to be killed,” he said to the Guardian last week. “But when I came today, I came to kill them. I came to protect the environment.”
Spotted lanternflies can’t harm humans or animals. But they drink the sap of a hundred different plant species and damage crops and trees, reports Gizmodo’s Angely Mercado.
When they drink sap, lanternflies weaken trees, making them more vulnerable to other pests and diseases. The bugs also release a sticky, sugary waste product called honeydew, per the Guardian, which attracts sooty molds that can interfere with plant photosynthesis.
Their spread has particularly alarmed the agriculture industry. In 2020, a study estimated the lanternflies could cause $324 million in yearly economic damages in Pennsylvania alone. The insects can feast on several plants, including walnut, oak, maple and apple trees, as well as cherries and grapes, according to the U.S. Department of Agriculture. And they have no natural predators in the United States.
Spotted lanternflies have a year-long life cycle. They finish growing into adults in July, mate in August and start laying eggs in September.
This summer might be a particularly big one for the bugs. Anne Johnson, an entomologist at Pennsylvania State University, tells Gizmodo that the lanternflies could be setting up a “boom-bust cycle” of abundance, which could explain the apparent surge in their numbers this year.
Scientists believe lanternflies arrived in the U.S. in 2011 in a shipment of stones, per the New York Times’ Anne Barnard. The first of these bugs in New York City were detected in 2020. Last year, they cropped up in Indiana. And Michigan reported its first sighting just last week.
The bugs wouldn’t have been able to spread so far without some (accidental) assistance from humans. “On their own, spotted lanternflies can only fly up to five miles,” Brian Eshenaur, senior extension associate at Cornell University’s New York State Integrated Pest Management Program, tells the Washington Post’s Kevin Ambrose. But they’re really good hitchhikers.
The adult bugs can travel by flying into car windows or attaching themselves to clothing. They also lay their eggs on cars, among other places. “I can’t think of something they don’t lay their eggs on—cloth, metal, furniture, sides of buildings and of course trees,” Ronnit Bendavid-Val, the director of horticulture at the Brooklyn Botanic Garden, told the Times’ Ginia Bellafante in 2021.
Officials recommend people check their belongings for bugs and eggs before leaving areas known to have an infestation. New egg masses are about an inch long and are brownish-gray, waxy and mud-like, according to the New York State Department of Agriculture and Markets. A Penn State guide recommends putting the eggs in a container with rubbing alcohol or scraping the eggs off a surface and stomping on them until each one has burst open.
As citizens embark on their spotted lanternfly-stomping crusades, they’re unlikely to kill every one of the bugs, urban ecologist Marielle Anzelone tells the Times. But it could be a first step toward taking higher-impact actions. “Maybe individual action is a way of pulling people in,” she says to the Times. “It’s not so much about that individual person’s […] three lanternflies they kill in a summer. It’s about educating and engaging and perhaps turning them into the person who calls their council member to ask for more funding for the parks department.”