Are they gone? Spotted lanternflies are still present, relevant in region

The spotted lanternfly was the talk of the town just a few years ago, but it appears that the conversation has slowed a bit as the insect becomes more mainstream. However, that timid dialogue might not be warranted. As researchers learn more about the spotted lanternfly’s habits and impact on the Pennsylvania ecosystem, the vigilance with which they must be approached has shifted. In doing so, Northeast Pennsylvania residents have a part to play.

Brian Walsh, a horticulture educator at Penn State Extension and spotted lanternfly researcher, is based out of Berks County. This area saw the initial rise of the spotted lanternfly in the western hemisphere in 2014. The insect has its origins in Asia and, according to Walsh, it likely ended up in North America as a result of commerce. Eggs were likely on a surface that was transferred across the Pacific Ocean, and that surface was in Berks County by the time it was ready to hatch. Walsh said it is highly unlikely that live insects were somehow transported from the spotted lanterfly’s native region to Pennsylvania.

Over the past decade, academics and the Pennsylvania Department of Agriculture have collaborated to learn more about the spotted lanternfly. The information gathered continues to expand, as does the insect’s geographic reach. These days, according to Vincent Cotrone, a regional urban forester and natural resource educator in the Penn State system, the spotted lanternfly is most prominent in Pennsylvania in the Pittsburgh and State College regions of Allegheny and Centre counties, respectively.

“From my observations, I’ve seen them, but not in large numbers in Luzerne County,” Cotrone said of the spotted lanterfly population.

However, he warned against complacency.

“I can’t speak for other parts of the state or even other parts of Luzerne County,” Cotrone said. “Somebody could have a ton of these in their backyard because, by chance, they have a tree of heaven growing near their property, or they have some grapes that are attracting them.”

An important discovery

Indeed, one of Pennsylvania’s most important discoveries regarding the spotted lanternfly is its relationship with trees of heaven (ailanthus altissima) and grape farms. Neither of those vegetation types might immediately sound relevant to Northeast Pennsylvania residents.

However, trees of heaven are an invasive species themselves, having been allegedly imported to Pennsylvania in the 18th century by the botanist John Bartram. Since their introduction, trees of heaven have sprouted up in scarred, disturbed lands like quarries and railroad cuts, which are fairly frequent sites in the former industrial hubs of Luzerne County. This can draw the spotted lanternfly to our area.

Northeast Pennsylvania must also be wary of the the spotted lanterfly’s tendency to ravage grape farms. The spotted lanterfly was originally transported here — albeit accidentally — as a result of commercial interests. Similar motivations for and methods of transportation can be the cause of carrying the bugs from Northeast Pennsylvania to areas where the grape industry is more prominent, such as Erie County, Upstate New York, California, and Ontario.

“If I’m a grower of grapes, I should be monitoring and really concerned about spotted lanternfly getting near my grapes and farm,” Cotrone said. “That’s where they would have their most impact.”

As trees of heaven are a “freak of a tree,” according to Walsh, their destruction is not of immediate concern. Most fruit trees are also going to be okay in areas with spotted lanternflies, but grapes do stand out as an exception.

“As an agricultural pest, it’s turned out not to be too much of a threat to our tree fruit industry — the apples and peaches. But it has turned out to be a significant pest of grapes,” said Walsh.

The solutions to these issues are still up for debate, but a few population reduction measures are generally agreed upon.

‘The critters are not gone’

“The critters are not gone, but the populations are lower because of several reasons,” said Cotrone.

The awareness campaign surrounding the dangers of spotted lanterflies has made the public well-informed. Though there may be a lessened sense of urgency in Northeast Pennsylvania as the spotted lanterfly sinks into the background of concern, Cotrone said that Luzerne County residents continue to bring up their presence in critical terms.

Efforts to squash spotted lanternflies on sight, however, are generally ineffective methods of true population reduction.

“Squashing them now is great, but we typically don’t suggest anyone actively go out and treat them at this point,” Cotrone said.

Instead, he suggests people explore their properties and look for egg masts. “Scraping” and permanently destroying those masts will make a more noticeable difference for residents looking to lessen the pests on their properties.

“The awareness campaign that we’re still all involved in is really good because, hopefully, we get people to notice and take that extra action of scraping,” Cotrone said.

Weather patterns and lanternfly lifespans

Weather patterns are also a huge indicator of population boom or bust when it comes to spotted lanternflies. Cotrone said that a late frost, such as one that comes in May, can severely and negatively impact the spotted lanternfly’s life cycle.

Walsh went a step further, noting that even harsher conditions might be necessary to truly make a dent in the spotted lanternfly’s lifespan. He suggested that a “freeze,” rather than a “frost,” is more effective.

“An earlier freeze would probably reduce the number of eggs that they are able to lay,” said Walsh. “One of the things that we have been noticing is that the egg-laying really starts around the equinox at the end of September.”

Therefore, it is fair for Northeast Pennsylvania residents to see more spotted lanternflies in September, even though they have been hatched for months.

In “normal” years, Northeast Pennsylvania and Northern Tier winters would be difficult to manage for lanternflies. However, as the seasons have subtly shifted in recent years and temperatures, on average, increase, the region is more susceptible to becoming a spotted lanternfly breeding ground. Just a few degrees can make a huge difference in the lanternfly’s ability to reach a mature age.

As it stands, the positive benefits of the spotted lanternfly are either non-existent in the Northeast Pennsylvania ecosystem — or at least muted. That being said, Walsh contested that coming to a clear verdict in the way of the spotted lanternfly’s impact on the Pennsylvania landscape is still unwritten.

“Take everything with a grain of salt,” Walsh warned. “These bugs … ten years since it was discovered, and we’re still learning a lot.”

In the meantime, the public protocol appears clear: squash the spotted lanternfly, and scrape and dispose of their egg masts.