The Latest Invasive Insect Threat All Homeowners Should Know About

The Spotted Lanternfly is decimating trees, orchards, vineyards, and other plants on the East Coast. Here’s how to protect your landscape from damage.

Top view of spotted lanternfly, Chester County, Pennsylvania

Photo: istockphoto.com

The U.S. federal government recently announced an invasive insect species’ arrival to the U.S.: The Spotted Lanternfly (Lycorma delicatula) is making its way across the East Coast, killing plants and trees, and leaving a sticky residue on porches and patios. The U.S Department of Agriculture considers the lanternfly a significant threat to crops.

What can homeowners do to protect themselves from this latest threat to the landscape? Kathy Glassey, director of renewable resources for Monster Tree Service, offers expert tips and advice on how to care for plants in the face of the Spotted Lanternfly.

What is a Spotted Lanternfly?

The Spotted Lanternfly (SLF) is a planthopper that originated in northern China. The adults have four wings. The front wings are grayish and have dark spots, and the back wings are black-tipped, white in the center, and bright red near the body. SLF females are 24 to 27 mm in length, while males are 21 to 22 mm.

Though it sounds from their description that the SLF would be fairly easy to spot, they undergo five stages of instars, or growth periods, in which they look entirely different. They lay eggs from August to early November and overwinter, hatching in late spring. The insects are relatively small throughout their instars and are often confused with ticks during their first through third instars.

“You can see these stages from about May through July,” says Glassey, “The fourth instar nymph has the first distinctive red color.” By late summer, the insect has reached its adulthood and congregates on trees. “The adults do not fly in the traditional sense,” explains Glassey, “But rather hop and glide.”

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How did the Spotted Lanternfly get here?

The SLF’s native range includes China, India, and Vietnam. It was first reported outside these countries in South Korea in 1932 and has since become abundant in Korea and Japan. The insect arrived in Berks County, Pennsylvania, via an overseas shipment in 2014 and has since spread through other states.

Where has the SLF spread?

In addition to Pennsylvania, the SLF has been detected in Delaware, New Jersey, New York, Ohio, Connecticut, West Virginia, and Virginia.

“Global commerce has created transportation opportunities for invasive pests to hitchhike and become introduced to new regions not exposed previously,” says Glassy. “The Spotted Lanternfly is a great hitchhiker and can travel along railroads or on cars, maybe even up to 60 miles per hour!”

Close-up of Spotted Lanternfly egg mass, Berks County, Pennsylvania

Photo: istockphoto.com

What type of damage does the SLF do?

The Spotted Lanternfly can be found on more than 70 species of plants, especially trees with smooth bark. They feed on sap in the phloem, the living tissue in vascular plants, which causes the trees stress and eventual decline. As they feed, SLFs excrete honeydew, a sugar-rich sticky liquid. Honeydew buildup promotes fungal, sooty mold to grow on the plant’s surface. The mold grows in black mats, interrupting the host plant’s ability to photosynthesize by blocking sunlight from the leaves’ surfaces. The honeydew also attracts other insects that can damage the plant.

The honeydew is also the SLF’s breeding ground. “Adult females lay egg masses that, on average, can contain 30 to 50 eggs,” explains Glassy, “These egg masses have been found in many places, including trees, tires, patio furniture, decks, fencing, and so much more.” The pest is particularly detrimental to grape plants as well as apple, oak, maple, and walnut trees. They cause extensive damage to the logging, wine, and orchard industries, to name a few. “It is critical to continue eradicating this pest,” warns Glassy, “as it presents a significant economic impact on our nation’s resources.”

Trap designed to trap Spotted Lanternflies, Berks County, Pennsylvania

Photo: istockphoto.com

What can homeowners do to stop the Spotted Lanternfly?

Early detection is the best defense. The pest can be destroyed through its various instars. “If egg masses are found, they can be scraped with a card and destroyed,” says Glassy. Egg masses can be found on any vertical surface and look like a smear of mud. Catching nymph or adult SLFs is challenging because they are mobile; spraying them with insecticide is not particularly effective. Some professionals use sticky traps or systemic insecticides, which are absorbed by the tree and affect the insects when they feed, to kill adult SLF.

Glassy says using common sense and due diligence can help stop the SLF from spreading. “If traveling through or if you live in a confirmed SLF area, be sure you have no hitchhikers traveling with you,” she says. “Follow your state’s quarantine guidelines and consider hiring a professional arborist to evaluate and provide treatment options.” And, if you have an Ailanthus altissima, or tree of heaven, on your property you may want to replace it. “SLF prefers this invasive tree species,” explains Glassy. Removing these trees from your property may keep the SLF from entering your landscape in the first place. To be on the safe side, have a professional inspect your tree and shrubs yearly to ensure early detection.

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