In summertime, you can’t walk down the street without squishing a lanternfly.
But in a lab, they’re not so prolific.
For years, researchers trying to learn more about the invasive spotted lanternfly and ways to kill it were limited by how hard it is to keep the invasive insects alive in captivity. It’s harder yet to get them to live through an entire life cycle, lay eggs and then have new lanternflies hatch out of those eggs, all in a lab.
It’s also expensive to feed the voracious bugs.
But in March, U.S. Department of Agriculture researchers were able to raise lanternflies to adulthood, have them lay many eggs, then have those eggs hatch and turn into adult bugs.
It’s a breakthrough that opens the door for more research, experts said.
“It’s easier if you’re working with an insect that’s easy to grow in a greenhouse or lab,” said Heather Leach, an Extension associate with Penn State entomology. “With spotted lanternfly, when we collect them and take them back to the lab on campus, they live for a couple weeks at most and just die out because they need so much food, and we can’t seem to keep them happy.”
For years, researchers have been trying to learn more about how to stop the spread of the spotted lanternfly, which landed in Berks County from Asia in 2012. Since then, it infested 26 other Pennsylvania counties, including the Lehigh Valley, as well as parts of New Jersey, Delaware, Maryland, Virginia and West Virginia.
A Penn State study released in January found the bug is costing the Pennsylvania economy about $50 million and eliminating nearly 500 jobs each year. If the insect were to expand statewide, it could cause $325 million in damage and wipe out 2,800 jobs, the researchers estimated.
Now researchers can study whether the eggs need a chill period ? marked in nature by winter ? before they can hatch, and what that means for whether the insects will spread south, said Julie Urban, a research associate professor at Penn State University. She’s also the project director for a multi-institutional grant focused on lanternfly research.
Urban said researchers can now study how the bugs mature from nymphs to adults and what dietary changes mean for their development.
“Because lanternflies are always moving on different hosts throughout the landscape, they’re seeking the nutrition they need, and that’s what makes them hard to predict,” she said. “If we can study them in the lab, we can study how they’re going to move around the landscape to meet their nutritional needs.”
She’s also hoping researchers will be able to figure out why lanternflies flock to one tree of a certain species and not another nearby tree of the same species.
Replicating the USDA process would still take a lot of personnel and space that Urban doesn’t have in her lab.
Tracy Leskey, an entomologist and the director of the USDA Appalachian Fruit Research Station who has been breeding, maturing and hatching the lanternflies, said she experimented with the lanternflies’ diet. She tried to feed them the shoots, branches and fresh-cut foliage from the tree of heaven, an invasive plant they love.
But nothing worked as well as small, potted, whole trees.
Once her lab raised the lanternflies to adulthood, they had to get them to lay eggs. Other researchers had gotten lanternflies to lay eggs, but not nearly in the numbers they wanted.
Leskey’s lab put out tree of heaven logs, and they started laying eggs “like gangbusters,” she said.
Another key component was keeping the insects in a chamber with 12 hours of light and 12 hours of darkness, mimicking summer in the mid-Atlantic region.
They observed the females laying one to three egg masses each.
Leskey started changing the lanternflies’ diets and the conditions they’re exposed to. She said being able to raise them in captivity will help people learn more about them, and help with determining how effective natural predators ? like wasps ? might be in killing them.
The next step, she said, is tweaking the process.
“We need to refine the protocols a little more so anybody could do it,” she said.
Morning Call reporter Michelle Merlin can be reached at 610-820-6533 or at mmerlin@mcall.com.
