Check for hitchhikers, and stomp if you’d like: Experts urge mindful management of spotted lanternflies

Spotted lanternflies have taken over Oakland, clinging to trees and littering sidewalks with their bodies, dead or alive. 

They may be a neighborhood nuisance, but in terms of statewide environmental damage, experts’ worst fears about the invasive insect haven’t come to pass. 

A recently published Penn State study found that spotted lanternflies, which feed on sap from over 70 different plant species, have limited potential to harm northeastern hardwood tree species. 

This latest research spells a sigh of relief for Pennsylvania’s commercial logging sector, which Penn State economists estimated in 2019 could face the loss of up to 1,518 jobs and about $223.9 million in annual economic activity due to spotted lanternflies. 

Concerns remain about the insect’s appetite for grape vines, but experts seem to agree that an all-out war on the spotted lanternfly could do more harm to local species than good. 

Stomp if you want, Phipps Conservatory Entomologist Braley Burke said, but “at this point, I think the best solution is not to do something.”

Among common methods of killing spotted lanternflies, sticky traps are a no-go, as they trap native insects and birds in addition to the invaders, and store-bought pesticides can linger in the environment for years, Burke added. 

For more discriminate ways of taking out spotted lanternflies, experts recommend circle traps, which are placed at the base of trees to funnel the insects into a dead-end collection container. Penn State Extension offers a guide to building circle traps using milk jugs, window screens and other everyday items. 

Laura Nixon, a United States Department of Agriculture scientist, said these traps are most useful in a research setting. 

“In the long run, this isn’t going to do a huge amount to the population itself,” Nixon said. “At this point, it’s more of a monitoring tool.”

If anything, residents should comply with the state-imposed quarantine of Allegheny County by inspecting their vehicles and personal belongings for spotted lanternflies before crossing county lines, Burke said. 

Native to China, the spotted lanternfly first appeared in the U.S. in Berks County, Pennsylvania, in 2014, and has since spread to most of the state. Out of 67 counties, 51 are under quarantine, with the northernmost counties largely spared. 

“Check your vehicle, check anything you’re bringing with you and stomp any insects that could be hitching a ride with you, because you don’t want to be the vector for spotted lanternfly in another place,” Burke said. 

The spotted lanternfly was first discovered in Allegheny County in 2020, and its numbers have since grown exponentially. A single female spotted lanternfly can lay around 100 eggs between September and November before dying off, and nymphs will begin to hatch from egg masses from April to July. 

A largely unchecked spotted lanternfly boom has placed additional duties on local groundskeepers. 

According to Pitt Vice Chancellor of Facilities Management Scott Bernotas, the University has begun removing Tree of heaven from its properties, another invasive species from Asia and the spotted lanternfly’s preferred host plant. Bernotas added that groundskeepers have been trained to recognize and remove overwintering egg masses.

“Meanwhile, Pitt will continue to clear the sidewalks of spotted lanternflies as needed,” Bernotas said. 

If it’s any consolation, Oakland is no worse off than any other neighborhood, according to Jaci Bruschi, a horticultural project manager with the Pittsburgh Parks Conservancy. The conservancy manages multiple greenspaces in Oakland, including Schenley Plaza, the Westinghouse Memorial Pond, the Schenley Park Visitor Center and the west and east Flagstaff Hill entry gardens. 

“I think the invasion is comparable to surrounding neighborhoods,” Bruschi said. “I am curious to see if a fluctuating trend will happen as the surrounding environment adapts to this new threat. Only time will tell.”

Patrick Cavanagh contributed to this story.