Invasion!

Photo: USDA  |  Photo illustration: Tia Kropko

The spotted lanternflies are coming. These sneaky invaders are a menace to more than 70 types of plants. Viral videos have raced across social media, showing hordes of lanternflies covering buildings and tree trunks. They hop from plant to plant, sucking sap from branches, stems and trunks.

The epicenter of the lanternfly invasion is Berks County, Pennsylvannia, where the insect was first discovered in the U.S. back in 2014. Native to Southeast Asia, the spotted lanternfly has captured attention for its ability to spread quickly. In the four years since its discovery, the insect has spread from one county to 13. It also has been spotted in Maryland, Delaware, New York, New Jersey and Virginia.

“I think we’ll really start to see this pest explode in 2019,” says Jill Calabro, science and research programs director for AmericanHort.

In June, the Pennsylvania Department of Agriculture suggested the spotted lanternfly might cause $18 billion in damage statewide. In August, Rick Roush, dean of Penn State University’s the College of Agricultural Sciences, called it “potentially the worst introduced insect pest since the arrival of the gypsy moth nearly 150 years ago.”

The horticulture industry has been watching warily, waiting to see if these hoppers will hop onto their radar.

“They know, but they’re not sure if they need to be concerned just yet,” Calabro says. “I think people are kind of waiting to see if this will be a real concern for our nursery industry and for the landscape managers. Chances are, some folks will definitely be impacted.”

• Make sure you also check other equipment being moved, like outdoor machinery, propane tanks and shipping containers. If you’re a business owner, keep a close watch over your property and park in areas away from the tree line. To capture nymphs and adults, you can wrap tree trunks with adhesive bands from May to August. You can also remove Ailanthus altissima (tree of heaven). These invasive weed trees are a favorite of spotted lanternflies.

• Most importantly, be vigilant to inspect both incoming and outgoing goods and the containers and equipment that carry them because they could be harboring a hitching pest as well.

• If you’re in a quarantine area, you can get information on management controls at aphis. aphis.usda.gov/hungrypests/slf.
  
  

• If you do encounter spotted lanternfly eggs, nymphs or adults outside of quarantined areas, report the sighting to your state Department of Agriculture.

Spot the invader

Adult spotted lanternflies are approximately 1 inch long and one-half inch wide. They are easily recognized by their large, visually striking wings. Their forewings are light brown with black spots at the front and a speckled band at the rear. Their hind wings are scarlet with black spots at the front and white and black bars at the rear. Their abdomen is yellow with black bars. Young nymphs appear black with white spots and develop red patches before becoming adults. Egg masses are yellowish-brown, covered with a gray, waxy coating prior to hatching.

While feeding, spotted lanternfly excretes a sticky fluid, which promotes mold growth and further weakens plants. As a plant hopper, it can move short distances on its own, but its spread has been aided by people who accidentally move infested material or items containing egg masses.

The spotted lanternfly is an excellent hitchhiker. It will lay its eggs on almost any flat surfaces, which facilitates its creep across county and state lines. All it would take is one egg mass on a railway car or shipping truck, and the East coast’s problem pest becomes a cross-country sensation.

The pest seems to be more of a threat to travel on inorganic material like metal than trees and shrubs.

“It doesn’t seem to be moving around so much on infested plant material.” Calabro says. “It’s more of a hitchhiker on just normal outdoor items, which is even more scary because it’s out of our industry’s control. Our industry is typically very good at being proactive at controlling pests. And this is just a pest that, in my opinion, will escape that.”

Containing the horde

Several states have established quarantines to restrict the pest’s movement. In September, USDA Animal and Plant Health Inspection Service and its state partners conducted lanternfly detection surveys in Delaware, Maryland, New Jersey, New York, Pennsylvania, Virginia and West Virginia to monitor existing pest populations and detect new outbreaks outside known infested areas. State ag department staff and local extension specialists are enlisting the help of citizen volunteers, area master gardeners and anyone willing and able to lend a hand.

“Any of the adjacent states and beyond, anyone on the East Coast should be concerned at this point,” Calabro says. “And frankly, the Midwest should start being concerned since Pennsylvania is a state with a population.”

Hope for control

USDA APHIS researchers are working on potential biocontrol solutions, including an egg parasitoid wasp. Spotted lanternfly overwinters in egg cases on the bark of the host tree. A wasp could parasitize those eggs before they hatch.

“As with any invasive, you research where it came from then go back and see what controls it in its native range,” says Eric Day, manager of the Virginia Tech Insect Identification Lab, which is helping monitor the insect’s geographic reach. 

The research team has to follow a slow, careful process to ensure a potential lanternfly biocontrol agent isn’t going to become a problem pest itself.

There are some conventional chemistry control measures for the nymphs and the adults. Calabro says the neonicotinoid class of insecticides, particularly dinotefuran, work effectively and quickly as a rescue treatment. Growers that have stopped using neonics can use bifenthrin as an alternative, but it won’t work as well due to its non-systemic nature.

A second method of control is tree banding – outfitting a tree with a band of sticky tape that contains and kills young spotted lanternflies. Penn State Extension’s recommended treatment for reducing the population includes installing sticky bands from mid-May to the end of August to trap lanternfly nymphs.

Researchers have also created “trap trees” by eliminating all but one or two trees of heaven and treating the remaining trees with insecticide.

In February, Secretary of Agriculture Sonny Perdue announced $17.5 million in emergency funding to stop the spread of the spotted lanternfly in southeastern Pennsylvania. More than 30 research projects are focused on understanding this invader, with more to come in 2019. 

PENNSYLVANIA DEPARTMENT OF AGRICULTURE

For more: https://extension.psu.edu/spotted-lanternfly; www.aphis.usda.gov/hungrypests/slf