Invasive bug to soon work way across Metro Detroit
By Carol Thompson, The Detroit News
Smears of crusted goo plastered the grip tape Tim Harrison pulled off a tree in southern Monroe County.
They aren’t patches of mud. The streaks were the leftovers of egg masses left behind by spotted lanternflies, invasive insects working their way through lower Michigan and the Midwest.
This early into the summer, the hatchlings from these egg masses are small nymphs, black with white spots. They will soon grow larger, a centimeter in diameter, and turn bright red. They will eventually transform into large, showy insects with striking gray and red coloring.
And eventually, the bugs that are limited to a few sites in southeast Michigan will make their way throughout the Lower Peninsula.
“It’s just a matter of time,” said Harrison, a Michigan State University graduate student studying entomology.
The Lower Peninsula — particularly cities such as Detroit, Lansing and Grand Rapids — is a ripe breeding ground for spotted lanternflies, Harrison said. The places are littered with the bugs’ preferred food, an invasive, fast-growing and common tree called the tree of heaven.
Spotted lanternflies have become a sensational nuisance on the East Coast, where they were discovered in the Philadelphia area in 2014. They are prolific breeders and voracious. They suck the sap from trees and other woody plants, leaving behind a sweet, sticky excrement called honeydew that attracts insects, and can build up and mold.
Cities pursued public awareness campaigns encouraging people who encounter a lanternfly to “squish it.”
Spotted lanternflies are in 18 states, according to the U.S. Department of Agriculture. They were first identified in Michigan in 2022 at a site in Pontiac. Since then, they have been seen in Monroe, Oakland, Wayne, Lenawee and Macomb counties.
Although annoying in high numbers, “they aren’t the end of the world,” Harrison said.
Unlike emerald ash borer and hemlock woolly adelgid, two other invasive insects in Michigan, spotted lanternflies don’t majorly affect the state’s forests or other ecosystems. They can damage vineyards and disturb outdoor gatherings, but they don’t threaten entire species.
“It’s a nuisance that we’re going to have to get used to because no matter what we do, they’re going to spread throughout lower Michigan,” he said.
‘Stinkweed,’ lanternflies’ favorite food
Spotted lanternflies’ spread through the United States depends on two things, Harrison said.
First is shipping. The bugs appear to have arrived on imported material from their native Asia. From there, they spread long distances along highways and railways radiating out from the Philadelphia area.

Second is the tree of heaven, an invasive tree that was introduced to the U.S. by European colonists in the 1700s and then by immigrants on the West Coast more than a century later. It has since spread widely.
“You’ll never stop seeing it once you know what it looks like,” Harrison said. “Lansing’s loaded with it, Detroit’s loaded with it. Ann Arbor, especially, is particularly bad.”
Spotted lanternflies love the tree of heaven and appear to breed more successfully when they lay eggs on the invasive trees compared with others. Cities that have lots of it “can expect very heavy infestations if treatments aren’t done,” Harrison said.
Removing the tree of heaven is one of the key strategies cities and landowners can use to avoid the incoming deluge of spotted lanternfly, Harrison said.
It won’t be easy, said Deb McCullough, an MSU forest entomology professor. The trees are incredible breeders. She said a single tree of heaven can produce 300,000 seeds, which blow around, float down rivers and plant themselves. The trees also release new shoots when their trunks are cut, making them hard to kill.
“Removing it is a lot of work,” McCullough said. “Somebody has to be motivated.”

Tree of heaven is also challenging to identify, said Fai Foen, green infrastructure director for the nonprofit Greening of Detroit. It looks similar to a black walnut tree or sumac, but its leaves smell like rancid peanut butter when crushed, she said — that’s why some people refer to it as “stinkweed.”
The tree is common in unkempt areas, such as railway corridors.
Foen said the communities first hit by a pest or disease can offer advice to others. Detroit found itself in a similar position with the emerald ash borer, the sparkling green beetles that decimated ash trees in southeast Michigan before spreading throughout the country.
Eastern communities are now in the position to advise Michigan on how to deal with spotted lanternfly. Foen said communities should convene to share education about the pest and to coordinate their response efforts.
“We’re in a position where it’s already here,” Foen said. “We should have that discussion.”
The Michigan Department of Agriculture and Rural Development this summer is monitoring sites for spotted lanternfly. The department’s monitoring efforts last year yielded new small populations throughout southeast Michigan. The department asks people to report sightings of the bug to Michigan.gov/eyesinthefield.
Unlike states such as Pennsylvania, Ohio, Maryland, New Jersey and others, Michigan has not imposed a quarantine to help slow spotted lanternflies’ spread.
“As we’ve seen in other states, stopping the movement of spotted lanternfly is extremely challenging,” MDARD spokesperson Lynsey Mukomel said over email. “Our current focus is on raising public awareness. By teaching people how to identify spotted lanternfly and avoid unintentional spread, we can help slow its movement and reduce its impact.”
Quarantines do not stop the bugs from spreading, but they do slow their spread, said Matt Helmus, a Temple University professor who tracks spotted lanternfly movements. Other states’ quarantines typically require commercial shipping companies and landscape industry businesses to inspect vehicles and wares for spotted lanternfly or the egg masses they lay in the fall.

“But when you have some type of quarantine and inspection, coupled with public informational campaigns, you definitely see that spread slowing,” Helmus said.
Harrison and MSU undergraduate field technician Madisyn Holman are studying the effectiveness of “lantern traps” for preventing lanternflies from flourishing. The traps are made with grip tape or roofing material, inexpensive supplies that can be purchased at a hardware store. By wrapping one piece of material on a tree and another domed top like a lampshade, they can make an environment female lanternflies find ideal for laying eggs.
The traps appear to lure a lot of egg-laying lanternflies, Harrison said, making them a cheap and effective way to reduce lanternfly breeding. He recommended people install traps in infested trees and squash the egg masses laid there.
Spotted lanternfly researchers have had to race to understand the bugs as they spread through the United States, said Brian Walsh, a Penn State University Extension educator and spotted lanternfly researcher.
Beyond recognizing the bugs’ taste for the tree of heaven, they’ve made some discoveries: The bugs can fly longer distances than people first expected, and they are somehow able to detect their favorite foods, such as grapes. Their populations follow a boom-and-bust cycle, sometimes so abundant they seem to fill the sky, then almost unnoticeable.
Vineyards brace for infestation
But even when they are in the “bust” cycle, spotted lanternflies consistently flock to vineyards, Walsh said.
“Growers shouldn’t panic, but they also need to have a game plan in place for how to deal with it,” he said. “Information is the key. Don’t panic, but being well-informed will help them make decisions that are going to benefit them in the long run.
“We don’t want people thinking this is going to end their vineyards or end their farms. It can be managed.”
Spotted lanternflies will reach Michigan’s vineyards eventually, Helmus said.
“It’s in Detroit, and now it’s in Chicago,” he said. “Think about all the people from Chicago that go up the west side of Michigan on vacation. It will probably spread into western Michigan. Relatively quickly is my guess.
“Once it starts to get into the vineyards, there’s going to be a lot more outcry.”
The first spotted lanternfly Anthony Vietri encountered was sitting alone on the ground near his vineyard in southeast Pennsylvania. It was “bizarre and gorgeous and frightening,” the Pennsylvania vineyard owner said.
By the next year, Vietri would be driving his tractor into clouds of spotted lanternflies, knocking dozens from the top of his fedora as he wound through the vineyard, wearing a cloth over his face to keep them from leaping into his mouth. They would drop from the trees like snow.
He’s learned to manage them at the vineyard, Va La Vineyards. When he prunes his vines, he scrapes off each egg mass he sees. The strategy significantly reduces the number that breed on his farm, which means he mostly just deals with the adults that fly in from elsewhere.
“Then it’s a matter of looking at them and saying ‘Hey, this is not as bad of an infestation as it could have been, and we’ll just ride this out,’” Vietri said.
Spotted lanternflies have not wiped out the Pennsylvania grape industry, he said, but they have taken a toll on certain vineyards that rely on expensive insecticides or host a lot of outdoor events.
“Weddings, outdoor events, they feel completely invited to,” Vietri said. “Unfortunately, the folks that are hosting that event or paying for it are not at all pleased about it, but there’s nothing really that the vineyard can do.”
Grape growers in northwest Michigan are concerned about what spotted lanternflies will do to their vineyards, said Nikki Rothwell, coordinator of Michigan State University Extension’s Northwest Michigan Horticulture Research Center. Growers have seen warnings from Pennsylvania about the bugs’ behavior and potential to swarm outdoor spaces like cities and wineries.
Michigan State Extension workers are experimenting with pesticides to control spotted lanternflies, but the number of bugs that can appear on a farm makes pesticide control difficult, Rothwell said.
“There’s not much you can do about them other than kill them,” she said. “They’re going to get here. I don’t really know why they wouldn’t come this far north.”