COLUMBUS, Ohio — An invasive fly that’s infesting parts of eastern Pennsylvania, where it threatens to decimate crops and kill trees, could spread across other parts of the country.
Spotted lanternflies invaded Pennsylvania in 2014 and, so far, the flies are winning the war.
There’s good reason to watch what’s happening there. The moth-like bugs, known for their hitchhiking ability, could migrate west.
Ohio, Indiana and Illinois would provide the ideal environments for lanternflies to take hold, according to the U.S. Department of Agriculture. Infestations are possible in New England, mid-Atlantic states and Pacific coastal states, too.
The regions have the best climate for the species, said Lisa Neven, a research leader with the USDA ARS Temperate Tree Fruit and Vegetable Research Unit in Wapato, Washington.
A model showing where the lanternfly could invade next was built using data from environmental factors including temperature, elevation and rainfall as well as known locations of the lanternflies.
Lanternflies are native to China, Bangladesh and Vietnam. About 1 inch long, the flies’ wings are gray, black and red with spots. Its abdomen is yellow with black bands.
The pests kill crops and trees by feeding on their sap. At risk are almonds, apples, blueberries, cherries, peaches, grapes and hops, along with oak, walnut and poplar trees.
“But it doesn't actually use all that sap. It has to get rid of it so it shoots it out as honeydew. It excretes it. They look like little super soakers. Honeydew is very sticky and it coats everything. It coats leaves and blocks photosynthesis and attracts mold that then damages the plant or the tree,” said Shannon Powers, a press secretary for the Pennsylvania Department of Agriculture. “It's just a mess for property owners."
Releasing hordes of praying mantises, directing the propane fueled flare of a blowtorch or dropping sticky napalm are just a few of the extreme measures people have taken. But those techniques aren't recommended.
“Those would all have a tremendous negative impact on the environment and would endanger children and animals. So you don't want to just obliterate them because in doing so you have unintended consequences. You harm other things,” Powers said.
Another county in eastern Pennsylvania with infestations was added to the list this year, bringing the total to 14. Residents in Philadelphia routinely stomp on lanternflies on sidewalks. There’s now an app centered around squishing them. Penn State fans commuting for games are told to check for lanternflies on their cars and belongings.
"Our hope is that by the time it arrives, a good method of control will have been worked out in Pennsylvania," said Celeste Welty, extension entomologist and associate professor of entomology at Ohio State University in an email.
One of the recommended measures is using sticky bands around trees coupled with insecticide treatments.
“That does kill very large numbers of lanternflies. I’ve talked to people who've removed wheelbarrow loads,” Powers said.
Part of the issue is the bugs reproduce at high volumes. When they do come into a new environment, their predators don't always travel with them, Neven said.
There's work being done to look for "other insects that prey on spotted lanternflies to bring that additional control into the ecosystem. But these things take a long time to do. And we always have to make sure that they don't harm our native species," she said.
"So yeah, it's like turning a kid loose in a candy shop and there's no adult there to tell them not to eat all the candy," Neven said.
Anyone who suspects they see lanternflies should call their state’s agriculture department.