The spotted lanternfly has spread across nearly all of Maryland since it was first detected in Cecil County in October 2018. As of 2025, the invasive pest has been found in 20 of the state’s 23 counties plus Baltimore City, and the Maryland Secretary of Agriculture has issued quarantine orders covering all of those areas. Only Worcester and Somerset counties have no confirmed infestations. If you live in Maryland, here’s what you need to know about identifying, reporting, and managing this pest.
Where Infestations Are Worst
Not all parts of Maryland are equally affected. Baltimore City and the central counties, including Baltimore, Howard, Prince George’s, Montgomery, Carroll, Frederick, and Washington, have the heaviest infestations. Allegany, Harford, Cecil, Kent, Queen Anne’s, and Anne Arundel counties have moderate populations. Lighter infestations are present in Garrett, Caroline, Talbot, Dorchester, Wicomico, Calvert, Charles, and St. Mary’s counties.
These levels are estimates and don’t mean a county is uniformly infested. Populations can vary dramatically within a single county. You might see thousands on one property and none a mile down the road, especially in areas where their preferred host tree is abundant.
How to Identify Spotted Lanternflies
Spotted lanternflies look different depending on the time of year, because they go through several life stages between spring and winter.
Nymphs hatch in May. The early-stage nymphs are small, about a quarter inch long, black with white spots. People sometimes mistake them for ticks. These black-and-white nymphs are active from May through July. In July, fourth-stage nymphs appear with a distinctive red coloration and white spots, growing up to three-quarters of an inch. They molt into adults by mid-August.
Adults are about one inch long with pinkish-tan wings covered in black spots that fold flat against their backs. When they open their wings, the hindwings reveal a striking red section with black spots, spanning about two inches. Both males and females have yellow abdomens with black stripes. Mated females develop swollen abdomens that make it hard for them to fly.
Egg masses are the hardest stage to spot. Females lay them from September through November, depositing 30 to 60 eggs in segmented rows about one inch long. They cover fresh egg masses with a putty-like substance that blends into whatever surface they’re on. Spotted lanternflies lay eggs on virtually anything outdoors: tree bark, rusty metal, camp chairs, stone walls, vehicles. Over winter, the covering cracks and weathers, making older egg masses slightly easier to notice.
The Role of Tree of Heaven
Spotted lanternflies feed on more than 70 plant species, but their strongly preferred host is the tree of heaven, another invasive species originally from Asia. This fast-growing weed tree is extremely common throughout Maryland, and its abundance gives spotted lanternflies a readily available food source that helps them multiply and expand their range. Grapevines, fruit trees, hardwoods, and ornamental plants are all vulnerable too, but tree of heaven is the anchor of the problem.
Because the insects are so attracted to tree of heaven, land managers use what’s called the trap tree method. The idea is to remove most tree of heaven on a property but leave a few standing. The remaining trees draw spotted lanternflies into a concentrated area where they can be treated and killed more efficiently. If you have tree of heaven growing on your property, removing it (or strategically keeping a few as traps) is one of the most effective things you can do.
What the Quarantine Means for You
The quarantine order applies to 20 counties and Baltimore City. For most residents going about their daily lives, the practical impact is limited, but it carries real obligations for businesses. Any business moving regulated articles within or through an area known to be infested must obtain a spotted lanternfly permit. Regulated articles include outdoor items that could harbor egg masses or live insects: landscaping materials, construction equipment, firewood, and similar goods.
To get a permit, businesses complete a training course through Penn State Extension’s Maryland-specific program, then receive their permit within a few weeks. The training covers how to inspect equipment and materials before moving them, which is the core of preventing the pest from hitchhiking into new areas.
Even if you’re not a business owner, the quarantine is a reminder to check your vehicles, trailers, and outdoor gear before traveling. Egg masses are the most common way spotted lanternflies spread long distances, and they’re easy to miss on bumpers, wheel wells, and outdoor furniture.
Managing Spotted Lanternflies at Home
On residential properties, management starts with awareness of what’s on your land. If you have tree of heaven, you have a magnet for spotted lanternflies. Removing those trees, or using the trap tree strategy described above, reduces the population’s food source on your property.
Scraping egg masses is one of the simplest and most effective actions homeowners can take during fall and winter. Use a flat tool like a putty knife or old credit card to scrape egg masses into a bag or container of rubbing alcohol or hand sanitizer. Check trees, fences, decks, patio furniture, and any flat outdoor surface. A single egg mass holds up to 60 eggs, so every one you destroy prevents dozens of new nymphs the following spring.
During the active season from May through December, sticky bands wrapped around tree trunks can catch nymphs and adults as they crawl upward to feed. If you use sticky bands, cover them with a cage of chicken wire or hardware cloth to prevent birds and other animals from getting stuck. Stomping individual insects is encouraged, and unlike many invasive species, spotted lanternflies are slow and clumsy enough that you can often catch them by hand or underfoot.
Reporting Sightings
If you’re in one of the three counties where spotted lanternflies haven’t been confirmed yet (Worcester, Somerset, or the remaining uninfested areas), reporting a sighting to the Maryland Department of Agriculture is especially important. Early detection in new areas helps the state respond before populations establish. The MDA’s spotted lanternfly page provides reporting tools and contact information. Even in heavily infested counties, reports of unusually large aggregations can help the state track how populations shift year to year.