The spotted lanternfly damages plants as it sucks sap from branches, stems, and tree trunks. The repeated feedings leave the tree bark with dark scars. Spotted lanternfly also excretes a sticky fluid, which promotes mold growth and further weakens plants and puts our agriculture and forests at risk. Submitted photo

Pennsylvania’s efforts to combat the rise of the spotted lanternfly may actually be working, as state agencies and wildlife experts report that the invasive species may be on the decline across the state this year.

According to Pennsylvania’s Department of Agriculture, there have been 9,292 reports of spotted lanternfly sightings so far in 2024 across the state, including 418 in Butler County. This is a steep decline from the 14,645 reports of sightings across Pennsylvania in the first seven months of 2023, and 38,947 up to Sept. 23 of 2023. Numbers for Butler County last year were not available.

However, Shannon Powers, press secretary for the Department of Agriculture, warns that numbers may be deceiving, as spotted lanternfly sightings are only counted when citizens go out of their way to report them to the state through the PDA’s hotline number.

“In areas where there aren’t that many lanternflies anymore, folks aren’t seeing the need to report them,” Powers said.

The spotted lanternfly’s first appearance in Pennsylvania — and the United States as a whole — was in 2014 in Berks County, near Philadelphia. It is believed that they first arrived via shipping containers from Asia.

According to Powers, lanternflies were first prominent in the Philadelphia area before moving westward.

“There tends to be like a three-year cycle. They peak in the third year and then they drop off precipitously,” Powers said. “After they hit Philly, it was about three years before they dropped off. That was certainly the case here in Harrisburg, and that has seemed to be the case in most counties.”

The first sightings in Butler County were reported in early 2023, when spotted lanternfly sightings were reported in Jackson and Cranberry Townships. In March 2023, Butler County was added to Pennsylvania’s spotted lanternfly quarantine area, which is currently at 52 counties. This now makes up all but 15 of the counties in the commonwealth.

Greene County, in the southwest corner of the state, was added to the list this March.

Although numbers suggest the spotted lanternfly seems to be on the decline in Pennsylvania, Diane Dallos of the Penn State Extension in Butler County believes that the invasive insect is only spreading further into Butler County.

“I just know they’re climbing through the county,” Dallos said. “We have areas that didn't have them in the past and are now seeing them. So they’re spreading.”

The spotted lanternfly life cycle lasts one year, and its stages change with the seasons. Fall is the season when adult spotted lanternflies lay their eggs, which hatch during the spring.

Regardless of whether the spotted lanternfly is on the decline or not, both Powers and Dallos insist that citizens continue to use the tools they have been using to combat it — namely, their own two feet.

“Every one that we stomp is one that won’t lay eggs for this winter to hatch next year,” Dallos said. “Any spotted lanternfly that is killed is decreasing the future population and getting rid of their nuisance for this year.”

Powers also cautions residents to watch out for spotted lanternflies hiding in plain sight — particularly in Allegheny County, which is still Pennsylvania’s hotspot.

“Watch your car before you travel. Make sure that you're not taking lanternflies with you,” Powers said. “We've been saying ‘Look before you leave’ for quite some time.”

If you are positive that you’ve seen a spotted lanternfly, you are urged to report your discovery to the Pennsylvania Department of Agriculture by calling 1-888-4BAD-FLY (1-888-422-3359).

SLF-spotted lanternfly (Lycorma delicatula) adult winged, in Pennsylvania, on July 20, 2018. USDA-ARS Photo by Stephen Ausmus.

Stephen Ausmus