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Maryland is bracing for an invasion of lanternflies, and racing to slow their spread

Spotted lanternflies in their fourth instar, or life-cycle phase, infesting a walnut tree in Pennsylvania last summer. (Courtesy of Emilie Swackhamer, P/HANDOUT)

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 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 other invasive insect in the Mid-Atlantic region, and it is proliferating more rapidly than the 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. Insect experts say a recent population explosion north of the Mason-Dixon Line means the bug is all but certain to appear in northeastern Maryland this spring, possibly as soon as in April.

The spotted lanternfly — ­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 lanternfly evolves in appearance as it passes through five developmental stages. During its first few weeks, it resembles a shiny black jewel covered with white spots. The spots are replaced with a brilliant red by midsummer. When the lanternfly reaches adulthood, it is 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 fliers, 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, arrived in the Philadelphia area in 1784 and has proliferated in much of the United States. Researchers say it is 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 cannot bring the fruit to market. And the insects’ gooey excretion, or “honeydew,” attracts insects and a form of sooty mold that 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 production.

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 thoroughly that the bark is no longer visible.

The U.S. Agriculture Department, which had already provided $5.5 million to help Pennsylvania researchers explore how to eradicate or control the lanternfly, recently announced it will provide $17.5 million more in emergency funding.

A few promising countermeasures have emerged, but so far they are 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 targeting the lanternflies that flock to the remaining 15 percent with one or more pesticides that have proved 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 in alcohol or hand sanitizer to kill them.

The relatively warm winter of 2016-2017 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 have held seminars in Cecil and Harford counties as well as in northern Baltimore County and shared photos and information by 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 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 is a chance they will 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.

“This is big enough and bad enough that it’s going to take over my life for the next couple of years,” she said with a sigh. “It’s a really big deal.”

— Baltimore Sun