The spotted lanternfly is poised to invade Maryland for the first time this spring. The invader has harmed important crops including grapes, fruit trees, hop plants and hardwoods, and left gardens, decks and patio furniture covered in goo.
Mary Kay Malinoski has seen plenty of harmful insects swarm into Maryland during her long career,from the tree-eating gypsy moth, which invaded in the 1980s, to the malodorous brown marmorated stink bug, which arrived in 2006.
But Malinoski, a veteran entomologist with the University of Maryland’s agricultural extension program, has never seen anything like the spotted lanternfly, a leaf-hopping pest that recently overran southeastern Pennsylvania — and that is poised to invade Maryland for the first time this spring.
The speckled, four-winged insect, native to China, Vietnam and parts of India, first appeared in the United States a little more than three years ago, when a shipment of stone from Asia arrived in Berks County, Pa., with lanternfly eggs attached.
Since then the invader has harmed important crops including grapes, fruit trees, hop plants and hardwoods, and left gardens, decks and patio furniture in more than a dozen Pennsylvania counties covered in goo. It feasts on more host plants than expected, reproduces more quickly than anticipated, and faces no known native predators. It also latches onto a wide variety of hard surfaces, allowing it to travel to parts unknown aboard cars, trucks and trains.
The spotted lanternfly appears to have caused more damage in less time than any invasive insect to arrive in the mid-Atlantic region, and it’s proliferating more rapidly thanthe researchers trying to learn about it can handle.
“If it does here what it has done in Pennsylvania, people are going to go crazy,” Malinoski said. “Our goal is going to be just to try to manage the problem and slow it down. This is really a nasty critter.”
One live adult spotted lanternfly has been sighted in Delaware and a dead one in New York, and a few living specimens were spotted in Frederick County, Va., in January; otherwise the infestation has been confined to Pennsylvania. Experts say a recent population explosion north of the Mason-Dixon line means the bug is all but certain to appear in northeastern Maryland sometime this spring, possibly as soon as in April.
The spotted lanternfly, also known as lycorma delicatula, is one of the more striking insects one is likely to see, but its behavior patterns have made it an altogether noxious guest.
One expert, Penn State entomologist Tom Baker, called it “the weirdest, most pernicious insect I’ve ever seen.”
The lanternflyevolves in appearance as it passes through five developmentalstages.During its first few weeks, it resembles a shiny black jewel covered with white spots. The spots are replaced by a brilliant red by midsummer. When the lanternfly reaches adulthood, it’s about an inch long and half an inch wide, and its grayish-brown wings — mottled with black spots — frame a bumblebee-yellow body.
Notoriously poor flyers, lanternflies flash bright red underwings when they hop or run, a practice believed to help ward off potential predators.
Emilie Swackhamer, a horticulturist with Penn State Extension, said the bug is so distinctive that 98 percent of the people who call in to report sightings have identified it correctly.
“These guys are so obnoxious on many levels,” Swackhamer said. “Many introduced pests, like the emerald ash borer, target just one plant, but the lanternfly has more widespread implications. it has the potential to affect a wide variety of people and industries.”
The pest’s favorite host plant is the ailanthus altissima, a deciduous sumac also known as the tree of heaven. This plant, also native to China,first arrived in the Philadelphia area in 1784 and has since proliferated in much of the United States. Researchers say it’s only one of 70 species on which the lanternfly is willing to gather to feed and reproduce.
The damage to those species starts with the lanternfly’s feeding style. Rather than consuming leaves, bark or fruit, the lanternfly uses its specialized mouth parts to penetrate a plant’s exterior, then sucks out the sweet, life-giving sap inside. This badly weakens the plants, leaving them vulnerable as winter looms.
For instance, the lanternfly robs grapes of so much sweetness that farmers can’t bring them to market. And the insects’ gooey excretion, or “honeydew,” attracts insects and a form of sooty moldthat can finish off the already weakened plants. It also sticks to houses, decks, railings and patios in infested areas.
Researchers have yet to get accurate tallies of spotted lanternfly populations, dispersal rates or crop losses, but anecdotal evidence suggests the numbers are high.
The Pennsylvania Department of Agriculture has declared the lanternfly a potential threat to the state’s $13.1 billion annual production of fruit and other crops and its $16 billion-a-year timber and wood industry.
The bugs arrived on Swackhamer’s family farm in late 2014, which she said “makes it personal.” She reports that egg masses and adult specimens are often known to overwhelm tree trunks so badly that the bark is no longer visible.
The U.S. Department of Agriculture, which had already provided $5.5 million to help Pennsylvania researchers explore how to eradicate and control the lanternfly, recently announced it will provide another $17.5 million in emergency funding.
A few promising countermeasures have emerged, but so far they’re developing more slowly than the bug is proliferating. One Penn State research team is studying genetic markers in hopes of pinpointing the lanternfly’s place of origin in China. That could help the team identify its native predators. Other groups are exploring the use of “trap trees” or eliminating 85 percent of the female trees of heaven in a given area, and then targetingthelanternflies that flock to the remaining 15 percent with one or more pesticides that have proven effective.
Swackhamer said researchers also have found a number of insects and parasitoid wasps that show promise as predators, including certain spiders and varieties of praying mantis.
For the time being, she urged residents to kill lanternflies by scraping egg masses off hard surfaces, double-bagging them and throwing them away, or by placing eggs into alcohol or hand sanitizer to kill them.
A relatively warm winter of 2016-17 led to an unexpected lanternfly population explosion last year and prompted the Pennsylvania agriculture department to place 13 southeastern counties under quarantine. Residents of those counties must secure permits before transporting across county lines any of several dozen items, including mulch, tree bark, decorative stone, tractors, barbecues and toys that have been kept outside.
Because lanternflies attach themselves to many surfaces, they easily travel from place to place. Swackhamer urged people to check their clothes before getting into their vehicles.
“They’re annoyingly friendly, and once you open your car door, they’ll jump right in,” she says. “We want people to be aware of what they look like and prevent them from hitching a ride.”
Malinoski and her Maryland extension colleagues have been working to spread the word about the likely incursion. They’ve held seminars in Cecil and Harford counties as well as in northern Baltimore County and shared photos and information in fliers and social media across Maryland.
Relatively few Maryland residents are aware of the problem, she said, but if residents become informed, they can report sightings early. She asked residents to view photos on her department’s website at extension.umd.edu/hgic/problems/spotted-lanternfly and to use the same site to report sightings.
The Maryland Department of Agriculture will be in charge of the state’s response, she said, with support from the U.S. Department of Agriculture and its Animal and Plant Health Inspection Services.
Experts say there’s a chance they’ll find a way to eliminate the spotted lanternfly, but until then, their best hope is to try to slow its spread.
In the meantime, Malinoski knows the problem will overtake her own existence in the same way it has infested Pennsylvania.