Citizen scientists lead fight in PA lanternfly invasion (2024)

It’s become a weird rite of summer in Western Pennsylvania: Somewhere between the lightning bugs in June and the cicadas in August, the invasive spotted lanternflies start clumsily flitting through our yards and public outdoor spaces, often crash-landing right onto our bodies.

By this point, we’ve all become inured to strangers randomly stomping their feet every few steps down the sidewalk, taking the Pennsylvania Department of Agriculture’s advice to “squash it, smash it … just get rid of it.”

So it felt quite odd when I received a package in the mail last September containing equipment for collecting live, unsquashed spotted lanternflies and preserving them in alcohol.

The strange package was my collection kit for the Spotted Lanternfly Invasion Archive, a citizen science project then in its first year of participation by the general public.

Participating in the project

I never thought I’d find myself staring at spotted lanternfly genitalia, but there I was in my backyard one evening shortly after my kit arrived, catching each one in a clear jar and holding it up to get a good look. Red spot on the abdomen? Female. All-black bottom? Male. My goal was to find five of each sex to eventually deliver back to Michelle Duennes, an entomologist and assistant professor of biology at St. Vincent College. She is also a co-founder of the Spotted Lanternfly Invasion Archive.

My kids, then 7 and 10, were instrumental in the specimen collection process. My daughter was the expert spotter – a skill she honed out of pure terror at the ever-present, clumsy insects. I would sex each one, and if it wasn’t the one we needed, I’d toss it over to my son, who’d stomp on it with his giant preteen feet. He also transferred the needed specimens to a separate jar in our kitchen. Once we had all 10, I stuffed them into the large plastic test tube I’d received in the kit and poured in some 70% isopropyl alcohol to preserve them for the eventual handoff.

Why do we need a Spotted Lanternfly Invasion Archive anyway?

Before we got into the project itself, I wanted to know more about how the spotted lanternfly wound up in our area to begin with.

“They are native to China,” Duennes said. “An analysis a few years ago showed that spotted lanternfly here are most genetically similar to spotted lanternfly from Korea, where they are also not native. So they first went from China to South Korea and then Japan.”

According to Duennes, the invasive insects first turned up in Pennsylvania in Berks County, likely on shipping containers from Korea. The spotted lanternflies did not immediately spread throughout the state, leading her to suspect trains and car travel as the probable vector for their arrival in Allegheny County. They have since spread to all but 15 of Pennsylvania’s 67 counties.

According to the U.S. Department of Agriculture, the insects are a particular threat to viticulture, as grapevines are a preferred host plant. They are also attracted to tree of heaven, an invasive plant that has proliferated in the Pittsburgh area, particularly at roadsides.

Getting the project rolling

The Spotted Lanternfly Invasion Archive started as an undergraduate capstone thesis project in 2022. Duennes recommended spotted lanternflies to her student, Clare Mulcahy, who was looking for a plentiful insect to study.

“She said, ‘Well, I want to study evolution, and I think I want to study insects’,” Duennes said. “She needed volume. And I was like, ‘Oh, there’s this new thing coming. It’s already in Pittsburgh, I’m sure we’ll be able to find plenty of them.’”

There were three problems. The spotted lanternfly hadn’t yet appeared in Westmoreland County. Mulcahy didn’t drive. And Duennes was teaching a lot that term. “And I was like, ‘Why don’t we see if people will help us?’” Duennes said. “‘My roller derby team will.’” Her appeal to the team: “‘You guys want to collect bugs?’ And a bunch of people did,” she said. “We got over 100 samples.”

The pair began doing DNA extractions on the samples, focusing on population genetics. They also started looking at the veins in the spotted lanternflies’ wings to see if they could notice any differences within Western PA’s population, but ultimately didn’t discover any.

“There weren’t any distinct differences based on geography in the wing patterns,” Duennes said. “But we kind of expected that because they haven’t been here very long. They haven’t really had much of a chance to adapt.”

Duennes realized that people were quite interested in the research based on the number of people who’d been willing to collect specimens for the project.

Then Assistant Biochemistry Professor Al McDonnell of Chatham University joined the effort, helping to name it and bringing a different expertise.

“So I’ve actually never worked with a bug before,” McDonnell said. “I’m a biochemist, so everything that I’ve worked with has been too small for the eye to see.”

One of McDonnell’s goals for the project is to do biochemical assays of proteins and DNA extractions of the gut to see what they’re ingesting or carrying.

“Maybe they’re not only eating what we think they’re eating, which is why they are so ingrained here and not somewhere else,” they said. “We don’t exactly know what they’re carrying and what they could be spreading. And maybe they’re carrying a fungi that’s unique. Maybe they’re carrying a bacteria that’s unique. But we just haven’t done those types of studies yet.”

Another of McDonnell’s goals is to have a sustainable lab where students collect their own specimens from different areas of the city and then learn scientific techniques they’ll need for future research by doing experiments with them.

Importance of citizen science

Both Duennes and McDonnell stress that the future of the Spotted Lanternfly Invasion Archive is in expanding the community science component.

“I think I’ve always wanted to start a citizen science project,” Duennes said. “I just love interacting with the community and showing people who don’t do science for their job that they can make a difference.”

“In everything that I do, I want it to hopefully tie back into the community in some way,” McDonnell said. “Mostly because in a lot of biochemistry programs, I don’t think students really get to connect it back to, ‘Oh, this could have an impact.’”

One of McDonnell’s students will work with one of Duennes’ to develop a curriculum around the project to introduce different biological concepts to high school students. Additionally, McDonnell’s student will create an instructional website to aid future archive participants in identifying the sex of each lanternfly, among other components of the project.

Last year, Duennes mailed out 425 collection kits and received about 100 back. Sign-ups for this year’s collection are now open to residents of Allegheny, Butler, Washington and Westmoreland counties.

Potential impact

Duennes said citizen scientists can be part of scientific history.

“This is a rare opportunity to study the origin of an invasive species from the very, very beginning,” she said.

Duennes pointed to a past DNA study involving historical bison hair samples taken from institutional collections that were used to look at changes in population over hundreds of years as an inspiration for expansion of the project.

“When [the spotted lanternflies] got here, it was like, this is an opportunity to do that from timepoint zero,” she said. “We can do that with our samples by saving them in ethanol. As long as we change the ethanol regularly, we can probably still extract DNA from them 50 to 80 years from now. And so we can study this species and how it changes over time.”

Beyond Duennes and McDonnell’s own research, the pair wants to get the collected samples into a museum collection, “which hopefully will last 100 years or so,” Duennes said. “And so there will be like this museum of all the people who’ve participated, and this museum will always be accessible to anybody who wants to use the samples.”

Squeamish about squishing?

Over the past few years, I’ve encountered many folks who don’t want to kill the spotted lanternflies for reasons as varied as their beauty or their presumed right to live.

Or, as Gabi Hughes, an environmental educator with Audubon Society of Western Pennsylvania, told me: “I’ve spent my whole life convincing kids not to squish bugs. I just can’t turn around now and say, ‘OK, just squish these ones!’”

I asked Duennes and McDonnell their thoughts on the squish-or-not debate.

“Just kill them,” McDonnell said.

“If you don’t want to squash them, sign up for a kit and put them in ethanol,” Duennes said. “And have their death mean something by sending it to a lab where it’s going to be used to study them.”

You may be more willing to help before they hatch by finding and destroying their egg sacs. There have been efforts by the Penn State Cooperative Extension and the Pennsylvania Department of Agriculture to educate the public on how to identify and destroy spotted lanternfly egg masses, which can be laid on many outdoor surfaces including tree trunks, porch furniture and even the wheel wells of cars.

“Around egg-laying time, I will inspect the wheel wells and underneath my car to try to find them,” Duennes said. Egg season runs from late summer into early winter.

Duennes recommends going through a car wash with an undercarriage spray to help dislodge any eggs that may be lurking on unseen parts of your car.

“They’re actually really easy to damage,” Duennes said of the egg masses. “…One of the main pieces of advice is if you find an egg mass, just take a credit card and scrape it off.”

Once the eggs hatch, an easy way to deal with them without touching or squishing is to use a circle trap, plans for which can be found on the Penn State Cooperative Extension website.

“Those are the most tested and most effective traps,” Duennes said.

Duennes can see a potential downside to all the eradication efforts, particularly in the evolutionary selection pressures humans may be putting on the invasive spotted lanternfly population.

“Are the things we’re doing to them causing them to evolve in response?”

Duennes has heard anecdotal evidence of lanternflies jumping away more efficiently, and wonders if efforts to take down tree of heaven could cause the bugs to switch to different plants.

“I could see a scenario where we kill all the [low-lying] ones, but now they just hang up in the trees and we don’t see them anymore, which maybe people will stop caring about them as much if they’re not literally in our face all the time,” she said.

“As we try to reduce the population, we are probably going to have these unintended effects on the population.”