Keep on stomping, Philly: Lanternflies return

The big picture: The planthoppers' feeding habits threaten Pennsylvania's vineyards, hops and nurseries, and they leave behind a sticky residue that breeds mold and attracts stinging insects.

The latest: The sap-sucking invasive pests have hatched and reached maturity.

If you see one: Squash it and scrape egg masses into a plastic bag filled with hand sanitizer.

• Pro tip: Lanternflies struggle to jump backward, so coming at them from the front gives you the advantage.

By the numbers: Lanternfly sightings in Philly proper hit 264 in 2024, dipping 14% from the previous year, per data from Pennsylvania's Department of Agriculture.

• That's a massive drop from 2019, when reports topped 11,500.

Meanwhile, sightings in some Philly burbs also saw declines last year:

• ⬇️ Bucks County: 22 sightings ('24) vs. 73 in '23
• ⬇️ Montgomery County: 64 ('24) vs. 171 ('23)

Threat level: Experts say the planthopper persists.

• The Department of Agriculture tells Axios that the number of reports tends to reflect public vigilance rather than actual lanternfly numbers.

Zoom out: Spotted lanternflies are now in more than a dozen states.

• In Pennsylvania, four more counties were put under quarantine this year, which regulates the movement of anything that could spread the insects.
• All but 11 of Pennsylvania's 67 counties are now under quarantine.

What's next: Scientists are studying lanternflies' potential natural predators as a way to help control their populations and reduce the need for methods like pesticide use.

The bottom line: "If you can conveniently kill them, kill them. But it's most important to not take them somewhere else," says Brian Walsh, a Penn State Extension lanternfly researcher. "Don't make the problem worse by misusing pesticides."

• He recommends Penn State's Management Guide for tips.