Should we still care about spotted lanternflies in Philly?
The initial concerns of a decimated agriculture business never came to pass, but the lanternfly in Pennsylvania is still a pest to be dealt with.
Nearly a decade ago, a faraway insect invaded Pennsylvania woodlands, threatening the balance of the ecosystem and millions of dollars in losses to local agriculture. Philadelphians went full Rambo: They covered the soles of their shoes in the guts of the invader, filled plastic buckets with thousands of carcasses and racked the slides of their salt-shooting air guns, ready for battle.
It was the mid-to-late 2010s and the Great War of the Spotted Lanternfly was underway.
The lanternfly was an invasive species first detected in South Korea in 2004, reported to have had the biggest impact damaging grapes and tree fruit, such as apple, or timber. Julie Urban, Penn State associate researcher in entomology, was one of the first scientists to be called upon in Pennsylvania in 2014 when the species was discovered in Berks County.
“Right away everyone was really concerned because where they were first discovered in Pennsylvania, you had a lot of vineyards and tree fruit production and timber is a big deal, too,” said Urban. The state soon quarantined affected areas and instructed residents to kill the pest.
Urban is an evolutionary biologist who studies “plant-hoppers” such as spotted lanternflies. At the time of the Pennsylvania discovery, the federal and state Departments of Agriculture and others were investigating how the insect entered the country, possibly on board pallets shipped from China to a local landscaping company.
Their worst fears? The decimation of Pennsylvania vineyards and timber production. In 2019, an economic impact study estimated that, if left uncontrolled, the lanternfly could cost the state $324 million annually and more than 2,800 jobs.
Over time, researchers and scientists expanded quarantine zones, tested new methods to control the pest, and educated the masses on how to deal with lanternflies — Pennsylvania’s Department of Agriculture handed down a kill-on-sight order that led to mass execution of the insect in Philly’s streets, especially when it reached the city about 2017. A local software developer even created an app in 2019, called Squishr, so people could compete with each other to kill the most lanternflies.
Almost a decade out from when the spotted lanternfly first touched down in Berks County, many wonder whether we’ve defeated the invasive species. Unfortunately, according to Urban, the battle to completely eradicate the insect was lost, as early attempts were not successful and the insect spread to a total of 14 states. However, the war is not over.
Should we still care in 2023?
The simple answer is yes, people should still stomp a lanternfly when they see one. However, lone soldiers taking out swarms by themselves aren’t going to make a dent in the population.
“Individual people stomping lanternflies isn’t a control technique on a mass scale. It was put in place because the lanternfly is such a good hitchhiker — if you don’t kill it, you’ll carry it,” said Urban. “We know that lanternflies spread with humans, so it’s more along the lines of trying to make people aware of it so they don’t carry it elsewhere.”
According to Urban, quarantining techniques used by the USDA and many state departments of agriculture to manage the outbreak on a large scale involve insecticides targeting large populations near high-risk transportation sites, such as Harrisburg’s airport or Philadelphia’s ports.
While scientists and residents won’t be able to fully rid the state of the bug, the good news is that its impact wasn’t as severe as initially expected.
“Based on feedback from growers in the industry, we weren’t hearing reports of damage in tree fruit,” said Urban. “Lanternfly feeding sustained over time can kill grape and tree of heaven, but it doesn’t really kill ornamental trees, like maples, or fruit trees. Their defense kicks in and instead of killing the plant, it’s more of a stressor.”
This means that many of the plants and trees expected to die from the invasion were able to fight back against lanternfly feeding (lanternflies use their piercing-sucking mouthparts to draw the nutrients and sap out of plants). Grapes and Pennsylvania’s vineyards, however, are the most severely impacted and are the current focus of protection efforts.
Urban says the bulk of the work done by scientists now is focused on new control techniques such as border sprays and exclusion netting for vineyards while researchers such as Urban study the evolution of the insect: how it feeds on plants, reproduces and migrates, and the production of its secretions, called “honeydew.” In one experiment, a post-doctoral researcher at Penn State was able to track and identify the stages of lanternfly feeding, using electrical current technology from the 1960s, according to Urban.
All of this is to say that spotted lanternflies are still a major issue to the agriculture industry in Pennsylvania, but everyday people no longer need to go out of their way to find and kill these insects. For now, scientists are leading that charge and figuring out the next steps of lanternfly evolution in the United States.
What to do if you see them.
It’s up to you, said Tony Croasdale, environmental education specialist at the Philadelphia Department of Parks and Recreation. As site director of the Wissahickon Environmental Center who oversees and manages several parks and nature sites in the city, Croasdale said lanternflies aren’t a priority the way they used to be.
“We have a massive park system with so many other impactful projects that there’s no reason to devote staff hours to something that isn’t going to be fruitful,” said Croasdale, who has worked with Parks and Recreation through the spotted lanternfly invasion. “Lanternflies are too widespread and established now. To protect your garden is one thing, but I also don’t think we should be so cavalier about killing anything. Plus, controlling invasive species should be part of a coordinated effort, organized and overseen by experts.”
Just as with plants in the agriculture business, your backyard garden should be OK even if spotted lanternflies show up, according to Urban. At most, they will put stress on your plants without killing them before they hop to another plant, and at the least, they might just be an eyesore if they’re spread all over.
To get rid of lanternflies, you can simply stomp, scrape or spray:
Stomp adult and nymph lanternflies when you see them on the street or in your garden.
Scrape lanternfly egg masses off of the trees, wood and smooth surfaces in your yard during the winter and put them in alcohol.
Spray insecticides on affected areas. However, Urban says to use caution with insecticides as they can harm other plants or beneficial insects such as bees. In addition, often an area will be treated for lanternflies only for the bug to hop to another plant soon after.
Pennsylvanians can take additional protective measures by inspecting their personal vehicles and cargo for lanternflies before traveling to other regions, Urban and Croasdale said.
- Julie Urban, associate research professor of entomology and planthopper expert, Pennsylvania State University
- Tony Croasdale, environemntal education specialist and director of Wissahickon Environmental Center, Philadelphia Parks & Recreation
