The species is invasive in the U.S. and can pose serious problems for the agriculture industries in many states. They can cause harm after feeding on sap from various plants.
The research team was led by Kelli Hoover, a professor of entomology at Penn State. She said the damage done by spotted lanternflies isn’t based on whether or not they visit a tree at all, it’s how long they stay.
“Our study represents a worst-case scenario in which the spotted lanternfly fed on the same trees for four consecutive growing seasons,” Hoover said.
The team reared spotted lanternflies in enclosures containing hardwoods for four years and found that all the trees survived. Through the study, they discovered that hardwood trees may be less vulnerable than initially thought.
“We know that it can kill tree of heaven, it can kill grapevines and on occasion, young saplings,” Hoover said. “But normally those are young saplings that are also being stressed by something else.”
She said plants exposed to a drought or too much rain can have a big impact, sometimes bigger than if a lanternfly stopped by for a few weeks.
“They move and after a couple of years of large numbers of lanternflies in a particular area, people notice that they tend to leave,” Hoover said. “We think that’s because they use up their food supply and they move to a better food supply.”
Because of this, she said the forests aren’t under as much of a threat as previously thought.
“More likely, nurseries need to worry about it if they have young trees and they’re heavily infested. Then I would probably treat,” Hoover said.
The Pennsylvania Department of Agriculture said if you do see a spotted lanternfly, you can smash them or scrape them off with a plastic card or knife. Then, soak them in rubbing alcohol or hand sanitizer.