How to identify and kill spotted lanternflies

If you need to get your mind off the pandemic for a moment, shift it to another plague sweeping the state: spotted lanternflies. It’s one you can play an immediate, and feel-good, role in fixing. And your mission is pretty simple: Find and kill the invasive species’ eggs. Who’s ready to get smashing?

“Honestly, it’s something fun you can be doing outside right now,” says Shannon Powers, press secretary for the state Department of Agriculture. “If you’ve got kids, keep them occupied by just sending them out and telling them to look for these treasures they need to destroy.”

The spotted lanternfly, Lycorma delicatula, is an invasive plant-hopper native to China, Bangladesh, and Vietnam. It was first discovered in Pennsylvania in Berks County in 2014 and has since made its way across the state, attaching itself to cars and trucks like a true hitchhiker. The lanternfly can now be found in 26 counties, most in the southeastern portion of the state, Philadelphia and the surrounding region included. In spring, their eggs start to hatch.

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While the black-polka-dotted, red-hind-winged bug might look cool (inspiring countless Halloween costumes), it’s a sap-sucking monster that can easily wipe out entire crops. It feeds on the sap of over 70 plant species and has a particular appetite for that of grapes, apples, hops, and hardwoods, all economically important plants. According to a study by economists at Pennsylvania State University, if not contained, the spotted lanternfly could potentially drain Pennsylvania’s economy of $324 million annually.

“They weaken the tree by feeding on it, and they do so in a very inefficient way, where they take in tremendous amounts of sugary sap, and then they shoot it out the other end — it’s a sticky mess,” explains Powers. “This gets all over the fruit, and it attracts a black mold, so you end up with double damage to the plant.”

That poop? It’s referred to as “honeydew” by scientists, and it’ll coat your backyard, patio, and neighborhood playground, too, making spotted lanternflies a nuisance that affects both quality of life and Pennsylvania’s agriculture industry, including local wine and beer production.

Here’s the better news: spotted lanternflies typically lay their eggs in giant masses, allowing you to eliminate up to 50 babies with one quick smash. Game on.

Spotted lanternflies start to hatch in the area as early as April, but you’ll find egg masses still intact into June. They lay their eggs on trees, rocks, patio furniture, and really any surface that’s somewhat flat. When checking your car, be sure to look underneath and in your wheel wells.

The egg masses look like light grayish, putty-colored splotches of mud.

“They lay 30 to 50 eggs in these neat rows, and then they cover them with this coating, which is what you’re seeing,” says Powers. “It’s shiny at first, but now looks more like a blob of dried gum flattened on a sidewalk.”

To kill the spotted lanternflies before they hatch, you can use a credit card, garden spade, or anything that’s stiff enough to scrape the coating off the masses and squish what’s underneath. Take your tool and apply enough pressure to the mass until you hear an actual “pop.” You may see juices spilling out. It might feel a little gross. Or glorious. Now’s when you channel all that built up pandemic aggression and air it out on the bugs.

“It’s not like a hornet’s nest — there’s no threat when doing this, so those of all ages can get involved,” says Powers. “You just want to make sure you really smash the eggs because otherwise, they can still hatch, even after you scrape off the coating.”

For a visual primer on how to remove spotted lanternfly eggs, check out this video from Pennsylvania State University Extension:

When you’re done smashing, you can scrape off the mass with your tool and let it simply fall to the ground.

As spotted lanternflies start to hatch, you can also make it your mission to kill those. Once hatched, the insect goes through four nymph stages. Nymphs in the first three stages are only ⅛-inch in size, making them hard to spot. They appear all black with white spots and can be found late April through July. Fourth-stage nymphs are about a half-inch long, with a red coat, white dots, and black stripes. These can be found in July through September.

By the time they reach adulthood, spotted lanternflies become fairly large (around an inch long) and highly mobile. Only the adults can fly. Their bodies are black, while their wings take on a black polka-dotted pattern, including their two hind wings, which are bright red.

Squishing hatched lanternflies is a much less efficient process than destroying the 30 to 50 eggs you can take out in one egg mass, but it’s still useful and encouraged. If you want to take your efforts a bit further, check out Pennsylvania State University Extension’s homeowner management guide. It dives into topics like tree traps, insecticides, and other methods that work to remove swaths of nymph and adult lanternflies.

When you find spotted lanternflies, you’re encouraged to report it immediately with the Pennsylvania Department of Agriculture’s online reporting system, or by calling 1-888-422-3359. Depending on the circumstances, the department will send a team of people out to survey the surrounding area and treat the issue.

“This is how we’ve been able to control the spread to some point,” says Powers.

This article was first published in 2020. It has been updated.

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