Spotted lanternflies lived in the woods near the apple orchard at Angora Fruit Farm, a Berks County park, and Brendan Lederer expected to find them fluttering, alighting and feeding on trees there last summer.
What he found surprised him.
They were dead: on the trees, on the ground. Mummified bodies of spotted lanternflies were trapped on trunks by some silky, weblike threads, their tan, gray and red dappled wings detached from their black and yellow bodies.
“They were almost frozen in place,” he recalled.
So Lederer, assistant director of the Berks County Parks and Recreation Department, snapped photos on his cellphone and sent them to researcher Heather Leach at Penn State, which has been studying the Asian sap-sucking pest that is plaguing Pennsylvania. Leach contacted experts at Cornell University in Ithaca, N.Y., who determined that the insect kill could be a discovery that will help Pennsylvania control the invasive bug.
Two fungi native to Pennsylvania worked in tandem to kill a large population of spotted lanternflies, according to Dr. Ann Hajek and Eric Clifton, the two Cornell researchers who have examined the dead bugs. The discovery could lead to an environmentally friendly weapon to control the insects, which were found in District Township in 2014, the first sighting in the United States.
Spotted lanternflies, ferocious eaters, feast on 70 different plants in Pennsylvania, and threaten the state’s $18 billion grape, tree fruit, hardwood, and nursery industries, according to the state’s Department of Agriculture. The bugs have spread to 14 counties in southeastern Pennsylvania, as well as three other states: New Jersey, Delaware and Virginia.
Lederer had noticed the bugs in the woods near the rows of apple trees that stretch up a hill at the farm, a quiet, cozy 22 acres of fruit trees, gardens and spring-fed ponds near Antietam Lake Park in Lower Alsace Township. The county purchased the property in 2013.
Trapped to death
Lederer was on a Penn State-led tour of Berks research sites, where various aspects of the bug’s life were being studied, when he learned the researchers needed a place to trap insects for their studies. He volunteered the farm. There was a cluster of tree of heaven, a favorite food of the lanternfly, in the woods near the apple trees.
On a subsequent trip to the woods, he discovered the dead bugs. He knew the area had not been sprayed with insecticide.
“Well, something is really working on them,” he thought.
He sent pictures to Leach, a spotted lanternfly extension associate at Penn State’s College of Agricultural Sciences who had visited the woods near Reading’s Pagoda to collect bugs for research.
“I just happened to be lucky to find the insects like that,” said Lederer.
The fungi – Batkoa major, found on the trees, and Beauveria bassiana, a soil fungus – worked together to kill “a large population” of spotted lanternflies, said Hajek, an entomology professor at Cornell. It’s uncommon for two unrelated fungi to work in tandem to produce such a large kill, she said.
Hajek and Clifton’s paper on their results of the investigation into the lanternflies’ deaths were published April 22 in PNAS, a scientific peer review journal produced by the National Academy of Sciences in Washington.
Deadly duo
Batkoa major, or B. major, killed 97 percent of the spotted lanternflies on the tree trunks and 49 percent of the bugs found on the ground, while Beauveria bassiana killed 51 percent of the insects on the ground, according to the paper. Only 12 egg masses were found at the site on Oct. 9, even though the spotted lanternfly’s egg-laying season had begun.
The B. major fungus infects insects like the spotted lanternfly with spores that anchor the bug to surfaces like a tree trunk. The spores shoot out of the insect’s cadaver and infect new bugs that touch it, according to the paper. Little is known about the fungus.
More is known about Beauveria bassiana, the soil fungus, which also infects the spotted lanternfly with spores through touch or the splash of rain.
The fungi act as pathogens, agents that cause disease.
The discovery is especially interesting because few other insects were killed by the fungi in the wooded area, according to Hajek. Among the 161 trees, most of them trees of heaven, and 43 shrubs, only one dead ant, one dead beetle and one dead stonefly were found.
More research will be done this year, said Hajek. Among the research subjects: environmentally friendly pesticides, registered by the Environmental Protection Agency, that contain strains of Beauveria bassiana.
“I think a lot of researchers are really excited about it,” Leach said, though more research into the fungi is needed. “It could be another option for the control program. I’m glad there’s optimism.”
Lederer is happy for the opportunity to contribute to the fight against the spotted lanternfly.
“I hope they’re able to do something with it,” he said.
