WASHINGTON COUNTY, Tenn. (WJHL) – While they won’t hurt humans, spotted lanternflies do pose a danger to important plant life in East Tennessee.

Adam Watson, who is an agent at the University of Tennessee Washington County Agriculture Extension, informed News Channel 11 about the harmful effects that spotted lanternflies have on local ecosystems.

“They feed on the sap of plants, leading to dieback and leaf damage,” Watson explained. “What makes them particularly concerning is their role as a stress inducer for plants.”

According to the Tennessee Department of Agriculture, lanternflies are an invasive species first located in the U.S. in 2014 in Pennsylvania.

The spotted lanternflies have now been observed in East Tennessee, with confirmed cases reported in Sullivan, Jefferson, and Knox Counties in 2025.

“While they don’t typically kill plants outright, they exacerbate conditions that allow diseases and other pests to thrive,” Watson said. “Their primary role is that of a plant stressor.”

Ben Lee, an assistant professor in the Department of Biology at East Tennessee State University, shared his experiences from plant studies in Pittsburgh, Pennsylvania.

“They’re ubiquitous,” Lee noted. “Attempting to squash them is futile and frustrating. In some areas, like parking lots, you can find them in the hundreds, paving the entire area.”

Lee said the main host for lanternflies is a tree called the Tree of Heaven, another invasive species.

“Tree of Heaven has been here a really long time in this country,” Lee said. “And so, you’ll find it pretty much wherever you go in the U.S.

“A lot of the research suggests that we really only see the lanternfly at high abundance where that Tree of Heaven is really high abundance. So, if we can remove those from the system, that’s a potential way to make the invasion not as bad.”

Lanternflies will also go after fruit trees and soybean plants.

“The lanternfly has a specialized mouth part that is designed to basically puncture into the stems of plants, especially trees, and to extract the sap from the phloem of the plant,” Lee said. “That can be problematic to the plant because it’s taking sugar, which is energy that the plant would use to grow, survive, reproduce.

“But then it’s also problematic because by extracting that sugary substance, it can actually lead to moldy growth. And if it falls on leaves, it can prohibit or inhibit further photosynthesis.”

Watson and Lee said one way to get rid of lanternflies is to destroy the egg sacks.

“On some trees, it can very much look similar to lichens on a tree,” Watson said. “It does blend in well with a number of different woody tree barks, so they can be hard to spot, but they also can be found on buildings, on vehicles, things of that nature.”

“You can scrape that off with a credit card or a library card or something like that,” Lee said. “Try to scrape it either into a plastic bag that you can then just throw into the trash, seal and throw into the trash.

“Or if you scrape it off into a bucket that has something like hand sanitizer or some other type of alcohol-based solution, something that will kill the eggs so that they won’t hatch.”

Lee and Watson also recommend squashing any adult spotted lanternflies.

If you believe you have seen a spotted lanternfly, report it to the Tennessee Department of Agriculture.