What happened to all the spotted lanternflies? The Philly insect invasion is at a low point 

It’s not your imagination — but the bugs aren’t gone entirely, experts say.

Spotted Lanternfly Pennsylvania
Matt Rourke / AP Photo
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You may have seen it — or not seen it, to be precise. There are fewer spotted lanternflies hopping around the Philadelphia region this year, experts confirmed.

Teams from the USDA and Pennsylvania Department of Agriculture tasked with treating and killing the colorful invasive species aren’t seeing as many here as before, according to Pa. Department of Agriculture spokesperson Shannon Powers.

The insects, which have plagued Southeastern Pennsylvania for at least half a decade, appear to be moving out of the area, Powers said, and taking their plant-destroying hordes elsewhere.

Why the lanternflies aren’t all over Philly this year remains a mystery.

“There isn’t really quite a definitive answer,” said Karen Verderame, animal programs developer at Drexel University. “There has been… what seems to be a decline in numbers in specific areas, especially in the areas where they’ve been established longer,” including Bucks, Montgomery and Berks County, where they first landed in the U.S.

Verderame oversees Drexel’s living collections. She emphasized more research needs to be done, but attributed the Philly area spotted lanternfly decline to three potential causes:

  • They’re getting eaten by predators that were initially apprehensive, including blue jays, crows and praying mantises
  • Some soil-based fungi that grow in this region have been found to be fatal to spotted lanternflies, according to a Penn State study
  • They’re becoming more widespread, branching out to other Pa. counties and states as far north as Connecticut

Did the squishing and egg-scraping efforts of diligent Philadelphians have anything to do with it? Unclear.

“I’d love to say that because Philly was such a great area at getting on the bandwagon and stomping them and having fun with it,” said Powers, of the Dept. of Agriculture, “I’d love to be able to say that that is what had the big impact. But we don’t know that for sure.”

Unfortunately, spotted lanternflies aren’t necessarily disappearing for good. Eight new Pa. counties further toward the central and the northeastern part of the state, including Lackawanna and Westmoreland counties, were added to the state’s quarantine list this year.

Beyond Pennsylvania, the bugs have been, well, spotted in New Jersey, New York, and even as far north as Connecticut.

Now, officials in New Jersey and New York are calling on their residents to band together to defeat this common enemy. The insects were first seen in New Jersey two years ago, but have exploded in population this year. New York’s first infestation was identified just last August in Staten Island.

Philly was added to Pa.’s spotted lanternfly quarantine list back in 2017, when they were first sighted in the city.

In 2019, and especially in 2020 when everyone was either trapped inside or forced to find respite outdoors, the bugs were inescapable. That was when the state agriculture department really pushed its campaign to eliminate the insects. Ordinary citizens suddenly had to be heroes. They were called upon to kill the lanternflies, by any means necessary, lest the invasive critter continue to degrade our local vegetation.

In case you’ve been lulled into a false sense of security, here’s a reminder of why these little creatures are our public enemy no. 1.

Spotted lanternflies feed on tree sap and while they’re eating, they’re also defecating which causes a deadly mold to grow on the trees. They feed on more than five dozen kinds of plants, but especially love grape vines and invasive trees of heaven. Spotted lanternflies decimated vineyards in Berks County, Powers said. She also advised anyone with a tree of heaven in their yard to literally remove it.

“They are still a concern because they can still cause so much damage to native trees as well as crops,” said Drexel’s Verderame.

Take note: the war isn’t over. Powers and Verderame both said it’s more important than ever to attack spotted lanternfly egg sacks in the fall and winter. Best to scrape them into a baggie of rubbing alcohol, per Powers.

“We’re not letting down our guard, just because they’re not in one area,” Powers said.

“All it takes is one pregnant female to come in, lay some eggs, and that’s 60 lanternflies the next year. Just because you’re seeing fewer in an area this year doesn’t mean you won’t have them back if you don’t kill them.”

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