Spotted lanternflies rest on a branch. Hatching season for the insect begins this month.(AP Photo/Seth Wenig)

Seth Wenig

With the start of spring comes the start of the hatching season for the spotted lanternfly, an invasive species of insect which has the majority of Pennsylvania on high alert.

Spotted lanternfly eggs, which typically are laid during the fall, begin to hatch in April. Those hatchlings grow into adults by midsummer and start laying their eggs by fall.

“The hatch begins in the second half of April to June,” said Diane Dallos, Master Gardener coordinator with the Penn State Extension in Butler County. “But they're very hard to see at that point, so it's best to be looking for the egg masses now in the next couple of weeks to help prevent population growth.”

It has been more than a year since Butler County was added to the state’s spotted lanternfly quarantine zone in March 2023, after sightings of the species were reported in Cranberry and Jackson townships the previous year.

The Pennsylvania Department of Agriculture said spotted lanternfly sightings in Butler County rose from 37 in 2021 to 955 in 2022 to 1,237 in 2023.

This year also marks 10 years since the first spotted lanternflies made landfall in the United States — reportedly via an overseas shipment to Berks County.

This year, one more county has been added to the quarantine zone — Greene County, in the southwest corner of the state. Only 15 Pennsylvania counties are not yet in the quarantine zone, and all of them are in the northern part of the state.

The spotted lanternfly feasts on all sorts of plant life, including plants that are vital to state economies, including those in the plant nursery, timber and winemaking industries.

Spotted lanternflies excrete a dark substance known as “honeydew” which attracts other insects and promotes the growth of mold. Because of this, the spotted lanternfly is considered a “plant stressor.”

A 2019 study concluded that, if left unchecked, spotted lanternflies could cause $324 million in damage every year to the state’s economy.

There have also been confirmed sightings of the spotted lanternfly in 16 other states and the District of Columbia.

However, for Butler County and other parts of Pennsylvania which have only recently seen a surge of spotted lanternflies, data from the Pennsylvania Department of Agriculture may bring some encouraging news.

“What we’re seeing is that they tend to peak in about the third year in an area,” said Shannon Powers, spokeswoman for the PDA. “Then they sort of move on. In Harrisburg, we didn’t see nearly the number of lanternflies in this area as we’d seen in the three years prior to that. It’s the same in Philadelphia, and same in Reading, and places where they’d been a little longer.”

For now, guidance has not changed regarding what to do if you see a spotted lanternfly or a mass of eggs in the wild. If someone spots a spotted lanternfly in the wild, they are urged to destroy it, and the same goes for masses of eggs.

Spotted lanternfly egg masses resemble dark smears of mud and can be found on any surface. They can be neutralized by scraping them into a container of rubbing alcohol.

“If you're out walking or gardening, or working on landscaping your yard, be looking for egg masses,” Dallos said. “You can either scrape them off and submerge them in alcohol, or you can stomp them and squish them. It's really important to make sure they're fully scraped and smashed.”

Pennsylvania’s spotted lanternfly quarantine requires all businesses operating within the zone, or traveling in and out of the zone, to acquire a spotted lanternfly permit. This permit demonstrates the business knows what a spotted lanternfly looks like and the dangers of transporting them.

“Everyone needs to be checking their vehicles before they leave home, before they leave their place of work, or anywhere that they're traveling to,” Dallos said. “They need to inspect their vehicles to make sure there's no egg masses or spotted lanternflies on their vehicle before departing.”

Pennsylvania Governor Josh Shapiro has pledged expanded measures to detect and combat spotted lanternflies as part of his 2024-25 budget proposal. These include $145,000 to support the training of a second SLF detection dog who will patrol Western Pennsylvania, and $3 million for a disaster readiness fund to respond to agricultural emergencies.

To report a spotted lanternfly sighting to the Pennsylvania Department of Agriculture, call 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

This is an example of lanternfly eggs that were left on a tree.

An example of spotted lanternfly egg masses. The state Department of Agriculture is asking people who spot these insects to report their location and, if possible, kill them in their tracks because the invasive species eats up crops, attracts mold and is a general nuisance.submitted by Penn State Master Gardeners of Butler County