Plague of Lanternflies Descending Across 14 U.S. States

Swarms of spotted lanternflies have been making their way across the eastern U.S., gobbling up trees as they go.

The invasive insect is native to China, and first appeared in the U.S. in 2014, in Pennsylvania. This summer, the bugs have infested 14 states on the East Coast and in the Midwest: Pennsylvania, Connecticut, Delaware, Indiana, Maryland, Massachusetts, Michigan, New Jersey, New York, North Carolina, Ohio, Rhode Island, Virginia and West Virginia.

"I've seen lanternflies build to populations where you can't even see the bark of the tree through the insect bodies," Emilie Swackhamer, a plant science expert at Penn State Extension in Collegeville, Pennsylvania, told New Scientist. "It's unnerving because you wonder what that's doing to the health of the tree."

spotted lanternfly
Stock image of a spotted lanternfly. These unassuming insects are actually invasive, and are infesting trees across 14 U.S. states. iStock / Getty Images Plus

The spotted lanternfly only measures around 1 inch. It has characteristic gray forewings with black spots, and red hindwings also with black spots. They feed on a wide range of fruit, ornamental and woody trees, according to the U.S. Department of Agriculture Animal and Plant Health Inspection Service (APHIS).

If allowed to spread across the U.S., they could decimate important trees from over 70 species, including almond, grapes, apple, peach, maple, oak, willow and pine. When the insects infest a tree, they suck the fluids from the plant tissue, which can eventually kill the plant. These trees being infected could cost the country millions of dollars: in New York alone, the wine and grape industry is worth $6.65 billion.

According to APHIS, spotted lanternflies hitchhike their way to new locations, laying eggs on tree bark, outdoor gear and cars. Signs of a tree having been affected by the lanternflies include oozing or weeping, a fermented odor, a buildup of sticky honeydew, and sooty mold visible on the plant.

Some models predict that the bugs could make their way to California by 2033.

Preventative measures suggested by APHIS include checking outdoor items and trees for spotted lanternfly egg masses, and destroying them, either by placing them into a plastic bag filled with hand sanitizer, or by crushing them. The egg masses appear brownish-yellow in color and contain 30-50 eggs, which are coated in a waxy substance that turns gray over time.

lanternflies
Stock image of several lanternflies. iStock / Getty Images Plus

Some states, including Delaware and New York, are encouraging residents to stomp on and kill the bugs if they spot them.

"We can understand the hesitancy to kill the spotted lanternfly, which appear colorful and harmless," Chris Logue, director of plant industry for the New York State Department of Agriculture and Markets, told the New York Times. "However, the damage this invasive species can do in harming important crops and impacting our food system is real. We just can't take the chance."

Even so, stomping the bugs to death is "not the management plan", Julie Urban, an insect scientist at Pennsylvania State University, told New Scientist. "The idea is that we can prevent it from spreading just long enough to give us a better long-term solution," she said. "Even though in the big scheme of things you're just buying a little bit of time, that little bit of time means a lot."

According to Urban, more effective solutions include insecticide treatments, careful monitoring of transport hubs and even biological control using fungus that infect the bugs.