The Bug That’s Eating America

Spotted lanternflies are native to parts of Asia. But in September 2014, they were sighted a long way from home—in the woods of eastern Pennsylvania. The bugs likely hitched a ride with a shipment of landscaping supplies from China. 

In their natural habitat, lanternflies live in balance with their ecosystem. A certain type of wasp, for example, preys on lanternflies, which helps keep their population from growing too large. That, in turn, means there aren’t enough lanternflies to wipe out plants that other creatures need for survival.

Here in the U.S., however, spotted lanternflies are an invasive species with no natural predators. As a result, their numbers are exploding. Over its six-month lifetime, one female will lay two or three masses of up to 50 eggs. And they lay their eggs on just about any hard surface. That includes trains, cars, and trucks, which then transport the eggs to new locations. By last summer, the bugs had made their way to 14 states, mostly in the Northeast. 

“They’re hitchhikers,” says Kelli Hoover, an entomology professor at Penn State University. “And they’re good at it.”

When they eat, lanternflies pierce a hole in a plant and slurp out its sap. Then they excrete a sugary substance called honeydew. The honeydew leads to the growth of a black mold that can weaken trees, spoil fruit, and kill delicate plants and vines. In Pennsylvania alone, lanternflies cause about $50 million in damage each year. Experts say that amount could grow to $324 million annually if the insects aren’t stopped.

As lanternflies spread, desperate local officials began asking Americans to take action—with their feet. People have been urged to stomp on any lanternfly they see. “Kill it!” the Pennsylvania Department of Agriculture begged on its website. “Squash it, smash it . . . just get rid of it.” 

In response, many people, like Milan, have become avid lanternfly slayers. When lanternflies infested her apartment building last summer, she began smushing them with a vengeance. She soon discovered that when she came at the bug head-on, she was more than twice as likely to kill it than when she crept up from behind. 

Curious about why, Milan studied a lanternfly under a microscope. She noticed tiny hairs on the bug’s wings. She theorized that the hairs acted as a warning system, helping the lanternfly detect threats. (Hoover confirms Milan’s theory—and that the bugs are best squished head-on.) Milan spread the word about her technique, even appearing on local TV. 

Milan is just one of many teens who’ve dedicated themselves to helping solve the problem. In Princeton, New Jersey, Joseph Miller and Sreya Jonnalagadda developed a technique for using a drone to spot lanternfly eggs so they can be destroyed before they hatch. And Rachel Bergey of Harleysville, Pennsylvania, engineered a trap that guides lanternflies up a tree trunk and into a net. 

Experts say that while these measures are unlikely to eradicate the bugs, they could help contain their spread, buying scientists time to find a long-term solution. And time is what they need, because in a few months, the next generation of lanternflies will hatch. And when they do, they’ll be very hungry.