Be on the lookout: Spotted lanternfly nymphs beginning to hatch

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A spotted lanternfly nymph on the Bethel Park branch of the Montour trail

Courtesy of Teresa Matuska

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A nymph at Teresa Matuska’s home in Canonsburg

Courtesy of Teresa Matuska

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Spotted lanternfly nymphs have emerged from their eggs, and if you see one, you are encouraged to use lethal force.

An invasive species native to China, spotted lanternflies were first discovered in Berks County in 2014. Since then they have moved west through the state, and the Department of Agriculture has placed more than 50 counties on the spotted lanternfly quarantine list.

Greene County was just added to the list this year, joining both Washington and Fayette counties. If a county is on the quarantine list, residents face potential fines if they move spotted lanternflies across county lines.

In 2023, the South Hills was a hot spot for the spotted lanternfly. Teresa Matuska, a master gardener with Penn State Extension Washington County, said it is difficult to pinpoint where exactly they will crop up this year.

“The patterns, they are not real predictable,” Matuska said. “While there was a lot of infestation in the South Hills, it’s not a guarantee that anything is going to happen this year.”

The spotted lanternfly life cycle begins as a nymph, typically hatching in May. They start as tiny black bugs with white spots on the back. By the end of July or in early August, they have grown into adults, about an inch long with wings. They stand out due to the bright red color of their underwings.

Currently, Matuska says the best people can do is to keep a sharp eye out for nymphs, and then “deal with them.”

“They are super hoppers. You have to be stealthy, or use insecticidal soap. It’s a good remedy to expedite their demise,” Matuska said.

Spotted lanternflies will attach themselves to trees, such as saplings, sumac or grapevines. Matuska notes that tree-of-heaven, which itself is an invasive plant, acts as a “host plant” to spotted lanternflies.

When it comes to their effect on the local ecosystem, Matuska said they are more of a “nuisance” than anything.

“They will stress out a plant. When the adults start feeding on the sap of a tree, they can only digest 50% of what they’re consuming,” Matuska said.

The excess sap is left behind as honeydew, which will develop black, sooty mold.

“That attracts other pests that will stress out a plant,” Matuska said.

Otherwise, spotted lanternflies do not pose a risk to people or pets, except as an annoyance.

Anyone who spots a spotted lanternfly is encouraged to squash it and report the sighting to Penn State Extension at extension.psu.edu/spotted-lanternfly.

As the spotted lanternflies become more prevalent over the summer, Matuska asks that people be aware so they can help stop the spread, rather than proliferate it.

“People need to pay attention. We are the ones that are spreading the lanternflies, because they can attach themselves and lay their eggs to about anything,” Matuska said.