Spotted lanternflies (SLFs) are hatching again across New York City. Though the first adult sighting hasn’t been officially confirmed by the state, reports of nymphs are already surfacing in multiple boroughs — including one that I found on my dog in Queens last week.
If you’ve noticed tiny black bugs with white speckles, especially near parks or tree trunks, you’ve probably seen one too. You might even have spotted a few of the invasive, sap-sucking pests hopping around your stoop or while flipping burgers over the weekend.
But don’t panic (yet). According to Brian Eshenaur, an invasive species expert with the New York State Integrated Pest Management program, SLF populations are unpredictable and often fluctuate from year to year.
What we do know is the population in 2024 was down compared to 2022 and 2023, when it was probably at its peak, he says. This is normal: SLF numbers tend to decline for a couple of years, and then sometimes work their way back up, like we saw in Pennsylvania, he says.
Spotting the truth about spotted lanternflies in NYC
In NYC, “part of the decline in the city might be because there are other insects and birds that do sometimes figure out, ‘okay, this is a food source that we can eat,’ ” Eshenaur said. “That would be a factor as well, with the predator populations building up.”
Still, some headlines have warned of a massive “surge in sex-crazed, crop-destroying” spotted lanternflies expected in NYC this year, citing high numbers in parts of Pennsylvania and speculating about a northward invasion.
But experts like Eshenaur say that’s not how lanternflies move — they’re not flying in from Berks County (the area where SLFs were first discovered in the U.S. in 2014). Spotted lanternflies only travel about four miles in their lifetime. What really drives their numbers in the city is local population growth, not out-of-state migration, he says.
So, what is changing in the city this year?
This spring’s mix of warm and cool days has made things a bit unpredictable, Eshenaur says. SLFs are cold-blooded and hatch when the temperature rises. Thanks to the urban heat island effect — basically, how heat reflects off concrete and buildings — New York City often sees earlier hatching than surrounding rural areas. That could explain why the nymphs are showing up a little ahead of schedule.
And if it does get hotter? We might be in for a longer, more intense SLF season. Adults usually show up around mid-July, but that timeline could shift depending on upcoming weather.
City bugs are changing, and fast
However, these insects aren’t just surviving in the city, they’re adapting to it. A recent study from NYU analyzing nearly 20,000 SLF sightings found that city-dwelling lanternflies are not only emerging earlier each year but sticking around longer too. The urban heat island effect gives them a kind of seasonal head start and extended run, making cities like New York a prime breeding ground.
A second study suggests lanternflies are also growing larger in more urban areas. Researchers believe that could affect how far they can travel, how many eggs they lay, and even how well they tolerate heat. City life may be helping them evolve into a more resilient superbug, one that’s even harder to squash.
New tools in the SLF-killing kit
The good news: scientists aren’t just sitting around waiting for the bugs to go away. These are just a couple of the most recent developments helping us better track and manage SLFs:
- Dogs are sniffing out egg masses. While my dog is oblivious to the SLF nymphs that hitch a ride on him, detection dogs trained by researchers at Virginia Tech University are out on the hunt.
They’ve been trained to locate and eliminate SLF egg masses, the Associated Press reports. In Cleveland alone, they’ve reportedly helped remove more than 4,000 SLFs. This might have prevented hundreds of thousands of lanternflies from hatching, according to a conservation expert.
- Scientists mapped the SLF genome. A joint research team from Kean University and NYU recently sequenced the lanternfly’s genome and identified genes tied to mating behavior and scent detection. This could lead to smarter traps, like pheromone-based lures, and even long-term gene-based control strategies.
- The NYU study findings also clarified how to tell males from females. (In short, females generally have a noticeable red spot at the tip of their abdomen, and they tend to be bigger and leggier.) It’s a key step towards using sterile-insect techniques in the future.
What you can do
Despite these new developments, the advice for residents stays the same:
- Vacuum them up. A handheld vacuum is still one of the best and easiest ways to remove nymphs and adults. Just make sure to wait at least 48 hours before tossing the bag or emptying the container to be sure the bugs are dead.
- Trap them before they grow up. You can place circle traps or sticky barriers on tree trunks to catch SLFs while they’re still crawling. Just avoid broad sticky tape unless you use wildlife guards—birds and squirrels can get stuck too.
- Skip the bug spray. Insecticides can hurt bees and other pollinators more than they help. “We really don’t recommend pesticides unless it’s absolutely necessary,” Eshenaur said.
While you’re at it, keep an eye out for red-and-black winged bugs. That’s the final stage before adulthood. If we start seeing lots of those, it could signal a boom year.
That said, there may be some natural reinforcements on the way. Remember the predators Eshenaur mentioned? Birds, spiders, and other insects may be preying on SLFs more. Even more species of fungi have been found attacking both nymphs and adults in Pennsylvania (good reminder to finally watch the new episodes of “The Last of Us.”)
Want to help?
There’s no formal SLF monitoring program in NYC like there is upstate, so researchers rely heavily on reports from neighbors. If you spot one (or a bunch), snap a photo and report it to the Department of Agriculture and Markets here.
You can also check out our original spotted lanternfly explainer here, which covers everything from what SLFs eat to how climate change is helping them thrive.
This post has been updated.
