Spotted Lanternflies Back With A Vengeance, Expert Says: What To Know In MD

MARYLAND — Spotted lanternflies are back with a vengeance in parts of Maryland this year, but there's good news. A decline in the pest's population could be on its way.

The spotted lanternfly, an invasive species native to eastern Asia, was first found in Maryland in 2018 in Cecil County. It has since spread to Allegany, Anne Arundel, Baltimore, Calvert, Caroline, Carroll, Charles, Frederick, Garrett, Harford, Howard, Kent, Montgomery, Prince George's, Queen Anne's, Talbot, Wicomico, and Washington counties and Baltimore City, according to the Maryland Department of Agriculture.

Adult insects have polka-dotted forewings and bold red underwings, giving them a distinctive appearance. Although it has the allure of a butterfly, the insect’s looks are deceiving.

Voracious eaters, spotted lanternflies feed on about 100 plant and tree species, including economically important crops such as grapevines, apple orchards, hops ornamental landscape plants, along with multiple tree species.

In an interview with WBAL, Michael "The Bug Guy" Raupp, professor emeritus of entomology at the University of Maryland, said areas of Maryland that didn't see the pest much last year are now overwhelmed.

"No. 1, they've been around. No. 2, they're more widely distributed throughout the state now and in areas where there were just a few, like my neighborhood in Columbia. Populations have exploded because there's simply more in those landscapes," Raupp told WBAL.

While feeding on plants, spotted lanternflies secrete a liquid known as honeydew. The liquid can develop an intense, rotten odor as it ferments and causes black, sooty mold, which can cover leaves and inhibit photosynthesis. Sooty mold can also cover manmade structures and be difficult to remove.

While spotted lanternflies won't bite humans or pets, Raupp said they may attract stinging insects like bees, yellow jackets, wasps and hornets.

Despite a boom in populations, a decline in the prevalence may be on its way, Raupp said in a separate interview with WTOP. The reason? They're a tasty snack for birds and other predators.

“What happens is the prey population increases, and then the predator populations will take a few years to increase behind that, but once they’re there, we’ll see dramatic reductions in those prey populations. In this case, the spotted lanternfly or the brown marmorated stink bug,” Raupp said.

Experts often urge people who see spotted lanternflies to destroy them. Contact insecticides may be used to control adults because many of them feed on the lower parts of trees where they are more visible and easier to reach with direct sprays.

Meanwhile, properly applied systemic insecticides can provide months of control by continuing to kill adults as they arrive.

In Maryland, the Department of Agriculture issued a quarantine for 20 counties where the spotted lanternfly is present. The purpose of the quarantine is to stop the spread of the pest to other counties.

"All other life stages of this insect, from nymphs to adults, can fly, hop, or drop into a vehicle – meaning that vehicles and equipment can easily and quickly help it spread," state officials said. "Therefore, a quarantine of an area found to be infested with the spotted lanternfly means that any material or object that could harbor the pest cannot be moved without taking precautions to prevent its spread."

Due to the quarantine, items including landscaping or construction waste, packing materials, plants, and outdoor items all require a permit to move within or from the quarantine area.

According to state officials, Marylanders should use this checklist for homeowners to determine if they have spotted lanternflies on their property.

"Thoroughly inspect all items presented on this list for any type of spotted lanternfly life stage and destroy all (lanternflies) that you discover," officials said. "This will help slow the spread of the insects to new areas."

Spotted lanternfly sightings should also be reported to the state through this online form.