Spotted lanternflies are gross. There’s no other way to put it. Not only do they cause havoc in your backyard, but it’s hard to enjoy your space during a bug infestation. Spotted lanternfly (SLF) nymphs started their infestation earlier than usual this year and are growing up sooner.
Experts say warmer temperatures earlier this year are responsible for accelerating their development. But arriving sooner does not mean the bugs will also die sooner — they will just have more time to wreak havoc on trees and make next year’s infestation worse.
Confusion around how to kill them
Confusion abounds on how to kill spotted lanternflies. Nextdoor and other social media neighborhood groups have constant discussions on what to spray on trees to end infestations.
We asked two experts about the insect, how to get rid of it, and why we should care. The interviews are condensed and lightly edited for clarity.
We first spoke with Brian C. Eshenaur, senior extension associate of Cornell University’s Integrated Pest Management Program.
The Escape Home: People have been sharing home remedies ranging from spraying vinegar to Dawn dish soap. What have you found useful that does not kill a tree when you spray it?
Eshenaur: We really have to be concerned about some of those home remedies. And if you’re trying to kill a pest like the spotted lanternfly, it has to have an EPA label for us to do that legally.
But for practical reasons, often those home remedies are not going to be effective. Something that is very basic, like vinegar, is going to be very acidic, which could harm the bark of the tree and even make its way into the tree. And it could alter the pH of the soil below. We want to avoid that, and some vinegars you can buy can be potentially harmful to us if you get it in your eye or other sensitive skin.
Soaps can be harmful to plant foliage if they are too concentrated or if they accumulate in the soil, the beneficial soil microbes and the roots could be harmed.
We do have a list, on our Integrated Pest Management website, of products that are labeled and legal to use. But most people are not going to use them.
Now, if you have a tree in your backyard — arborists can use a systemic product that they can inject into the tree, and then the whole tree is protected. And it’s only going to impact insects that are feeding on the tree, as opposed to just spraying it around. But those are limited to what tree-care professionals can use, so we wouldn’t have access to those as homeowners.
But if you’re gonna kill them, you can use a vacuum to control them. Some people have seen them on some of their vegetable plants and have used a handheld, battery-powered vacuum and that works.
The Escape Home: What do you do with them after?
Most of the time they don’t make it through the vacuuming process because when the vacuum brings everything through the impeller, it hits the fan and it kills him there.
But some of them can survive. If you open up the canister, they could fly out. So you can leave them in for about 48 hours. If they don’t feed within about 48 hours, they will die. If you empty that canister a couple days after you’ve done it, then you’ll know that they’re all dead.
If you have a lot of them in there, you wouldn’t want to wait beyond [48 hours] because the decaying spotted lantern fly, a large mass of it, can smell putrid.
The Escape Home: Spotted lanternflies, as a non-native species, have few predators here. Given this, would you encourage homeowners to refrain from killing stink bugs, praying mantis, and other species known to kill spotted lanternflies in their garden?
Absolutely. And if you are fortunate enough to have a garden, keep a little bit of a habitat area — something that is not manicured to a high degree — for beneficial insects.
Also, put in native plants that you know beneficial insects are more in tune to. Including some of those natives can be very helpful — things like butterfly milkweed.
We also spoke with Julie M. Urban, associate research professor in Penn State University’s Department of Entomology, about why we see SLFs everywhere, including up our legs, and how they escape.
The Escape Home: What makes spotted lanternfly nymphs so fast and so hard to kill?
Urban: This species and their relatives are called planthoppers. Spotted lanternflies’ hind legs have these gear-like structures that allow them to pop. So they’re really specialized jumpers. Adults are larger, so there’s a bit of a trade off — they are able to fly and to glide, so that certainly helps them with any escape, but they’re larger, so their body mass will slow them down a little bit compared to nymphs.
The Escape Home: Why might you see them on the ground or on other low-hanging plants, instead of permanently up in your tree, where they have access to food and are farther from predators like us?
Urban: They’re just constantly on the move. You might see nymphs in your yard or on some rose bushes one day, and then the next day they’re on something completely different. Especially the nymphs, in those early stages, they have smaller mouth parts, so they feed through the leaves and on more herbaceous tissues, rather than through wood.
This is part of the reason why they’re so problematic and why they’re so hard to detect. In every life stage, they feed on a lot of different things, but especially those early instars, feed so broadly on so many different plants. They’re kind of diffused across the environment. With other insects, we aggregate them so they all come to one place and you can catch them there. With these guys, we haven’t found a lure that works.
The Escape Home: What is the best trap to use? Some parks officials have expressed concerns about the safety of using traps on trees – for other wildlife and for the trees- especially given the costs of putting up traps.
Urban: Birds have gotten stuck on sticky band traps. The circle traps’ risk is a little less problematic than the sticky ones. But there are modifications that a person could do to make the sticky traps safe. PennState still doesn’t recommend them, but if you were to look online, there’s the bug barrier trap.
The Escape Home: If you want to try killing SLFs one bug at a time, what’s the best way to do that?
Urban: Taking something like a Snapple bottle just a little bit above them and they jump up into it. Then, if you were to put [rubbing] alcohol [or hand sanitizer] in there to kill them, that would probably be the quickest and most humane way to do it. They’re never going to jump backwards, so everything is forwards. If it’s on the ground, it just might be easier to stomp them.
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This article has been lightly edited and adapted from an article produced with Epicenter NYC.