When I moved to Pennsylvania in January, one of the first things I did was visit the state farm show. As I walked the booths, I kept seeing warning signs to watch out for an insect called the spotted lanternfly.
I’d never heard of it before, so I stopped at a booth run by a local forestry group. By the time I finished talking with the woman there, I was shaking. And if you own a fruit farm or woodlot in the eastern US, you should be too.
Spotted lanternflies aren’t really flies. They’re more closely related to cicadas. The adults are about 1 to 1 ½ inches long. They have translucent wings with black spots. When they fly, you can sometimes spot a bright red underwing.
Adult spotted lanternfly. Check out the MyWoodlot slideshow on how to identify spotted lanternfly for more information about this invasive insect’s egg and nymph stages. Photo credit: Pennsylvania Department of Agriculture, Bugwood.org
Spotted lanternflies are a brand new invasive insect. Originally from China, they arrived in the US in 2014. They were first found in Berks County, Pennsylvania, and they’ve spread rapidly from there. They’ve expanded throughout southeastern PA, and earlier this year, a dead adult was found in Delaware County, New York.
Range map of spotted lanternfly as of April 2018. Red dots signify areas where spotted lanternfly is present.
Spotted lanternfly is one nasty bug. As both nymphs and adults, they use their piercing mouthparts to poke into trees and other plants and suck out the sap. Affected trees often develop oozing wounds on the trunk and mold at the base from all the released sugars.
Damage caused by spotted lanternflies includes oozing wounds on tree trunks (left) and mold at the tree’s base (right). Photos credit: Lawrence Barringer, PA Department of Agriculture, Bugwood.org
Spotted lanternflies will feed on lots of trees and plants. They’re a particular problem for fruit farmers, because they feed heavily on grapevines, apple trees, and stone fruits like peaches. For woodlot owners, common hosts include maple, oak, pine, walnut, sycamore, poplar, willow, and Tree of Heaven. That diversity of host plants makes this invasive more problematic than emerald ash borer, which limits its damage to one kind of tree.
Fortunately, there’s no evidence (at least right now) that spotted lanternfly directly kills the trees it feeds on. Unfortunately, it often kills them indirectly. The feeding weakens the tree and makes it more vulnerable to other stressors like drought. Also, the mold and oozing wounds attract other insects that can damage the tree further and ultimately kill it.
Even if spotted lanternfly doesn’t kill a plant, all that feeding reduces the plant’s ability to produce fruits and seeds. That hurts fruit farmers and makes it harder for trees in the woods to reproduce.
What can you do about this nasty newcomer to our orchards and woodlots? We have some new MyWoodlot resources to help. First, get familiar with how to identify spotted lanternfly. Next, learn how to slow its spread to keep it from reaching your land. Finally, if it does reach your land, know how to control it to limit its numbers and the damage it causes.
Most important, if you see spotted lanternfly, report it right away (see list below). Because this pest is so new, there’s a lot we still don’t know about it. Knowing where it is will help agencies learn more about it and improve control efforts.
Massachusetts: Fill out this form.