Egg masses can be found on any vertical surface and look like a 1?-inch smear of mud or clay. Females lay the eggs in rows before covering them with a protective layer that starts out glossy white but fades to a mud color and develops cracks. Although it seems like they can’t fly (or more accurately, hop) very far, the insect lays eggs on vehicles, firewood, and other objects that travel more freely, helping to speed the spread.
I’ve noticed these egg masses on my own patio furniture, and they’re surprisingly easy to miss if you’re not looking closely. They blend in with rough surfaces like tree bark or weathered wood. If you’re in an area where spotted lanternflies are a problem, it’s worth taking a closer look at anything that’s been sitting outside for a while. According to the USDA, each egg mass can contain 30 to 50 eggs, so catching them early can prevent a much bigger issue later. A good tip is to check in the fall when females are laying eggs, as the glossy white coating is a bit more noticeable before it fades. If you’re unsure whether what you’re seeing is an egg mass, try comparing it to photos online or consult your local extension office for guidance.
How to Destroy Spotted Lanternfly Eggs
The pest can be destroyed throughout its various instars, or growth periods, but ¡°if egg masses are found, they can be scraped with a card and destroyed,¡± says Glassey. Scrape them into a Ziploc bag, add enough hand sanitizer to cover them, then zip the bag shut and dispose of it. Other ways to destroy the eggs are to smash them with a stick (or your hand), as long as you apply enough pressure to burst all of the individual eggs. As you’re cleaning your deck and patio this spring (and closing it down again in the fall), it’s a good idea to check all outdoor furniture and decor¡ªincluding grills, patio furniture, and garden planters¡ªfor egg masses. Regularly checking trees and plants for signs of spotted lanternfly eggs or damage is important for anyone living in an area where the pest already is deemed a threat or where the potential exists. Be sure to report your sighting to your local agriculture office as well.
I’ve tried the Ziploc bag method myself, and it’s oddly satisfying to know you’re stopping dozens of lanternflies before they hatch. One thing to keep in mind: hand sanitizer is cheap and effective, but you can also use rubbing alcohol if that’s what you have on hand. If you’re smashing the eggs, make sure you’re thorough¡ªmissing even a few can mean a new batch of nymphs in the spring. The USDA suggests checking not just your own property but also nearby public spaces, like parks or trails, since these pests don’t respect property lines. Reporting sightings isn’t just a formality; it helps local agencies track the spread and allocate resources. For example, in Pennsylvania alone, the economic impact of SLF has been estimated in the millions due to crop and forestry losses, so every report counts.
What Is a Spotted Lanternfly, Exactly?
The spotted lanternfly 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 millimeters long, while males measure 21 to 22 millimeters. Though it sounds from their description like the SLF would be fairly easy to spot, the insect undergoes five stages of instars, in which they look entirely different. The spotted lanternfly life cycle begins around August to early November, when the insects lay eggs. The eggs overwinter, and hatch in late spring¡ªusually around May. The insects are relatively small, 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.¡±
It’s wild how different these bugs look at each stage¡ªI mistook a nymph for a tick once and nearly panicked before realizing what it was. The life cycle is key to understanding how to fight them. Since eggs are laid in late summer to fall, that’s your window to catch them before they hatch. The nymphs, especially in their early stages, are tiny and black with white spots, which makes them blend into shadows or leaf litter. By the time they hit that bright red fourth instar, they’re a bit easier to spot, but they’re also more mobile. If you’re curious about their biology, the SLF’s ability to hop and glide comes from specialized hind legs, a trait common in planthoppers. This hopping can make them tricky to catch, so focus on eggs or use traps for adults. Local extension services often have workshops or online guides to help you identify each stage, which can be a game-changer for early detection.
How Did the Spotted Lanternfly Get to the U.S.?
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. ¡°Global commerce has created transportation opportunities for invasive pests to hitchhike and become introduced to new regions not exposed previously,¡± says Glassey. ¡°The spotted lanternfly is a great hitchhiker and can travel along railroads or on cars, maybe even up to 60 miles per hour.¡±
It’s kind of scary how easily these pests can travel. I remember hearing about a case where SLF eggs were found on a shipment of stone from Asia, which shows how global trade can accidentally spread invasive species. The SLF’s hitchhiking ability is a big reason why it’s popped up in places as far apart as Ohio and California. Studies suggest that invasive species like the SLF cost the U.S. economy billions annually, with agriculture and forestry hit hardest. If you’re traveling through an infested area, take a minute to check your car or camping gear for eggs¡ªthink of it like checking for ticks after a hike. Some states have set up checkpoints to inspect vehicles, especially for things like firewood, which is a common way SLF eggs spread. Being proactive here can save you and your neighbors a lot of trouble down the line.
Where Has the SLF Spread?
In addition to Pennsylvania, the SLF is considered a threat in Connecticut, Delaware, Indiana, Maryland, Massachusetts, New Jersey, New York, Ohio, Virginia, and West Virginia. Although some states’ conditions are less suitable for the insect to take hold, most have at least one area with some risk based on local climate. The risk is highest across the northeastern states where it’s already a threat, along with parts of California, Oregon, and Washington. In February 2023, sightings or infestations around the Northeast had been reported as far west as Indiana and southeastern Michigan, and as far south as the Carolinas. In 2021, the state of California established quarantine measures to prevent the insect from entering the state from infested areas; without these measures, it was predicted that the insect would be established in the state by 2033. Just like how they hitchhike on global transports, these prolific pests can travel throughout the United States on nearly any wood product, vehicle, or commodity. The insect is considered an invasive species in the United States and South Korea.
The spread of SLF is a bit like watching a slow-motion invasion. I live in an area where they’re just starting to show up, and it’s unsettling to think they could become a bigger problem soon. The USDA’s quarantine maps show that the Northeast is the epicenter, but warmer climates like California’s wine country are also at risk because of the SLF’s love for grapevines. Data from 2023 indicates that over 50 counties across the U.S. have reported sightings, with the Northeast seeing the highest density. If you’re in a high-risk area, it’s worth checking your local agriculture department’s website for updates¡ªthey often post maps or risk assessments. For homeowners, knowing your region’s risk level can help you decide how aggressive to be with prevention, like checking firewood or outdoor equipment before moving it.
What Type of Damage Does the SLF Do?
The spotted lanternfly can be found on nearly 100 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 also doubles as the SLF’s breeding ground. ¡°Adult females lay egg masses that, on average, can contain 30 to 50 eggs,¡± explains Glassey, ¡°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 grapes, apples, oaks, maples, and walnuts. They cause extensive damage to the logging, wine, and orchard industries, to name a few. ¡°It is critical to continue eradicating this pest,¡± warns Glassey, ¡°as it presents a significant economic impact on our nation’s resources.¡±
The damage these bugs cause is no joke¡ªI’ve seen grapevines in a neighbor’s yard completely covered in that sticky honeydew, and it’s a mess to clean up. The sooty mold is particularly nasty because it can spread fast, especially in humid conditions, and it doesn’t just affect the plant’s looks; it can kill it over time by starving it of sunlight. The wine industry in places like Pennsylvania has taken a hit, with some estimates suggesting losses in the tens of millions due to SLF damage. If you’ve got fruit trees or valuable hardwoods like oaks, it’s worth keeping a close eye on them. A practical tip is to hose down affected plants to remove honeydew before mold sets in, but you’ll need to pair that with pest control to stop the cycle. Regular monitoring, especially in late summer when adults are feeding, can save you a lot of heartache and expense.
How to Fight a Spotted Lanternfly Infestation at Home
The insects tend to gather at dusk or nighttime, and might be easier to spot at that time of day. Catching nymph or adult SLFs is challenging because they are mobile. As with any pest control strategy, first try preventive measures, like destroying eggs. If prevention fails, try the least toxic remedies, escalating to insecticides as a last resort. Research effective biopesticides that can destroy spotted lanternflies without harming beneficial insects. Sticky traps might hold them until you can dispose of them. Less-toxic choices such as oils and soaps also can be effective. Spraying spotted lanternfly with insecticide can be effective if you can catch them gathering. EPA-registered chemicals that work on contact or systemically include dinotefuran, bifenthrin, zeta-cypermethrin, and carbaryl. ¡°If traveling through or if you live in a confirmed SLF area, be sure you have no hitchhikers traveling with you,¡± Glassey says. ¡°Follow your state’s quarantine guidelines and consider hiring a professional arborist to evaluate and provide treatment options.¡± If you have an Ailanthus altissima (or tree of heaven, an invasive tree and noxious weed) on your property, you may want to get rid of it. ¡°SLF prefers this invasive tree species,¡± explains Glassey. 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 trees and shrubs yearly to ensure early detection.
I’ve had some luck with sticky traps around my maple trees, but you’ve got to check them regularly to avoid catching birds or beneficial bugs like ladybugs. The tree of heaven tip is a big one¡ªthose trees are like a magnet for SLF, and I had one removed from my yard last year, which seemed to help. If you’re considering insecticides, start with something like neem oil; it’s less likely to mess with pollinators. The cost of professional treatment can vary, but in my area, a single visit from an arborist runs about $100-$200, depending on the property size. If you’re in a quarantine zone, check for local programs¡ªsome states offer free or subsidized treatments. Also, don’t underestimate the power of community effort; talking to neighbors about checking for eggs or traps can make a big difference, since SLF don’t stay on one property. It’s a team effort to keep these pests in check!