The spotted lanternfly is raising is raising more questions than answers, it seems. A recent and widely-publicized infestation is sweeping across Lancaster County, causing concerned home and business owners to wonder what kind of action they should take.
Is it a plague that will kill all our trees? Can they be controlled? We’ve heard these and many other questions.
Some unscrupulous companies are trying to profit by prescribing treatments that are environmentally dubious at best. While it is understandable that property owners wanting to get rid of them hire exterminators to spray the bugs, we believe the only responsible approach is to select and protect valued trees. (Calling an exterminator to kill bugs in your home is one thing. Having them spray an outdoor landscape, with bugs blowing in from the next county— will not get rid of them, but will have unintended consequences for the ecosystem, such as killing benign insects.)
So we’ve put together this list of frequently-asked questions, based on what our customers have been asking. And asking, and asking…
SPOTTED LANTERNFLY FAQ
What exactly is the spotted lanternfly?
The spotted lanternfly has wings but doesn’t fly much, because it’s what’s known as a plant-hopper. However, it can travel on the wind, and its egg masses travel over long distances when attached to vehicles. Native to China, India and Vietnam, the spotted lanternfly loves to feed on ailanthus (tree of heaven), which is itself an invasive species. Unlike another well-known invader from Asia— the emerald ash borer— the spotted lanternfly has an appetite for many of our native species, including maple, birch and walnut, as well as grapes and hop plants.
When did the spotted lanternfly get here?
First discovered in 2014 in Berks County, the spotted lanternfly has been spreading in all directions since then, and is currently in the process of blanketing Lancaster County from east to west.
What is the government doing to stop it?
In May of 2019, the Pennsylvania Department of Agriculture announced a spotted lanternfly quarantine. It currently covers 14 counties, according to the PA Department of Agriculture’s Spotted Lanternfly Alert.
Spotted Lanternfly Quarantine Map
Businesses and organizations that move vehicles in and out of the quarantine zone must get a spotted lanternfly permit. Residents are asked to use this spotted lanternfly checklist before moving outdoor items such as travel trailers outside of the 14-county quarantine zone.
My trees have been treated— why are there still lanternflies on there?
The treatment doesn’t put a giant protective bubble over your property. The insects can still fly in from other properties. What the treatment does is protect your tree. When they try to feed on it, they die.
What can I use to kill them?
You should avoid home remedies to control spotted lanternfly, says Penn State Extension. The Internet is full of them, including dish soap, vinegar, salt, boric acid, vegetable oil and more. They can harm humans, pets and plants.
The best approach is to have your arborist apply a systemic pesticide that will remain in the tree and kill all insects that feed on it. This not only protects the tree, but is better than indiscriminately spraying the landscape. We believe it’s impractical and environmentally unsound to spray the insects directly.
Do their eggs die off in winter?
No. The adults die, but the eggs survive.
Will they infest all my trees?
No. They are attracted to some trees more than others, even trees of the same species, for no discernible reason.
How long does your treatment last?
One growing season. So yearly treatment is needed.
Will they be back next year?
What is the black goo all over the trees?
The bugs use a piercing-sucking mouthpart to tap into the tree’s fluids, and excrete honeydew, or sugary water. This sugary surface encourages the growth of black sooty mold, which is harmless to people but attracts other insects. At minimum, it is bothersome and unsightly, and at most it can be damaging to the tree.
How many treatments do I need to get rid of spotted lanternflies?
This question contains a faulty assumption. As arborists, our mission is to protect your trees, not to eradicate spotted lanternflies from your property. In fact, there is no way to prevent the spotted lanternfly from moving onto your property, and we believe that should not be your focus.
By annually treating your most valued trees, we can protect them from the damage spotted lanternflies cause (and in the process, kill all of the insects that attempt to feed on the tree).
I can see what looks like egg masses. What should I do?
Scrape the mass using a piece of plastic or wood into a container of rubbing alcohol or sanitizer. If you feel like getting physical, you can squash the eggs to destroy them instead. To learn more, watch this video from Penn State Extension about destroying spotted lanternfly egg masses. Then, we encourage you to use the Pennsylvania Department of Agriculture’s spotted lanternfly reporting tool.
Do they bite or sting?
Will your spotted lanternfly application hurt my pets and kids?
No. Just keep them away from the tree for a couple of hours until it dries.
Why not just spray all trees?
Indiscriminate spraying is environmentally irresponsible. Insecticides will kill not just spotted lanternflies, but beneficial leaf-hoppers, as well as other good insects in the ecosystem such as butterflies.
Will the spotted lanternfly kill my tree?
There is no documented case of that happening. However, heavy feeding by spotted lanternflies does weaken the tree, causing loss of leaves and making the tree susceptible to other maladies, such as root rot fungus. When the tree’s defenses are down, secondary pests can come along and kill the tree. So while it’s not a tree-killer like the emerald ash borer is to ash trees, it is bad for the tree and should be controlled.
How do I decide whether to treat my tree?
It depends on how you value your tree. We can come out and discuss the situation with you to help you decide.
Is it a bad idea to plant new trees right now?
No. Chances of any individual tree becoming infested are not high. And every tree, even a newly planted one, can be treated if necessary. The treatment is not bad for trees of any age.