Penn State

The spotted lanternfly is causing havoc in Pa. Why it will be in Centre County ‘eventually’

An invasive species of insect from Asia, called the spotted lanternfly, puts dozens of Pennsylvania’s plants and crops at risk, as well as leaves “honeydew” behind after feeding, which can create a mess for homeowners.

While it’s not a problem in Centre County yet, it likely will be.

The spotted lanternfly was first found in the United States in 2014 in Berks County. Since then, it has spread to 13 counties in southeastern Pennsylvania, which is designated as a quarantine zone.

There’s a lot of research going on at Penn State to learn more about the biology and behavior of the spotted lanternfly, as well as the best insecticides to use to kill it and other effective management tactics that aren’t chemical, said Heather Leach, spotted lanternfly extension associate at Penn State.

The host list for the spotted lanternfly includes 70-plus species, and that’s continuing to grow as more is learned about the insect, she said.

“The threat really is not limited to any one specific crop or plant and so that makes it really difficult to manage,” she said.

What the lanternfly does — and how to stop it

Efforts to keep the pest from spreading out of the quarantine zone, Leach said, include requiring that businesses that transport material check to make sure they’re not also letting the spotted lanternfly hitch a ride; suppressing and reducing the populations in the quarantine zone; and building a “moat” around the quarantine zone.

Some homeowners in the quarantine zone have reported issues with “honeydew” — the spotted lanternfly uses its piercing sucking mouthpart to suck plant sap out of the trunk, branches and leaves of plants, she said. But with the nutrients it’s getting, also comes sugar water, which the lanternfly excretes as waste, or honeydew.

She said the honeydew can start to accumulate near where the lanternfly feeds (like a tree overhanging someone’s deck). Then “sooty mold” can grow, feeding off the honeydew.

People have had to power-wash their decks, and Leach said she’s some gotten complaints of people having trouble selling their homes in the quarantine zone because the honeydew and sooty mold.

Will it come to Centre County?

Centre County, for now, is free of the pest.

“There have been isolated reports of individual insects, but no established populations in Centre County. These are most likely insects that ‘hitchhiked’ there on vehicles or items being transported out of the quarantined area,” Shannon Powers, press secretary for the Pa. Department of Agriculture, said in an email. “Most reports in Centre County have turned out to be other insects.”

Each reported sighting is investigated by a team that confirms the insect’s presence and then surveys thoroughly to determine whether there are others, she said.

The state Department of Agriculture has tracked reported sightings since 2014.

“The potential for it spreading is, to be frank, really high,” Leach said.

The state and federal ag departments are doing a great job keeping the insect contained in Pennsylvania, Leach said, but it’s an insect with a population that is very high and controlling it is really difficult.

“I do expect it to come to Centre County eventually. Whether that’s next year or in a few years, I’m not quite sure,” she said.

Leach said she thinks county residents should be aware of the pest and check to see if they have tree-of-heaven — one of the spotted lanternfly’s preferred hosts and also an invasive species — in their backyards. If so, they may want to consider removing them or, at least, keep an eye on them and use them as a monitoring tool.

Are Christmas trees safe?

And with the holidays approaching, it wouldn’t be a bad idea to check your Christmas tree for egg masses. Leach said the spotted lanternfly doesn’t feed on Christmas trees, but it’s not out of the realm of possibility that they could lay eggs on them.

Egg masses are about an inch to an inch and a half long and look like a “gray splatter of mud,” Leach said, adding that underneath that covering is rows of seed-like eggs (about 30 to 50 in each egg mass).

If you do find egg masses, they can easily be removed and killed, Leach said, by scraping them off the surface with a credit card, putty knife or even a stick and then making sure all the eggs are smashed. (You also can place them in alcohol, Powers said.)

Were you to bring an egg mass inside on your Christmas tree accidentally and the nymphs hatched, which Leach said is really unlikely, they would die within a few hours because they’re weak and wouldn’t have anything to feed on. They wouldn’t hurt humans or pets, she said.

“The best thing that we can do is get early reporting in Centre County because if it’s here, if we spot it ... early on in the population ... we’d be able to come in (and) eradicate that population locally,” Leach said.

If you suspect you’ve seen a spotted lanternfly or egg mass, you can report it online at or call 1-888-4-BADFLY.