- Invasive spotted lanternflies have officially moved into Kentucky
- Lanternflies feed on the sap of trees, which can lead to tree death over time
- There are a variety of mitigation measures you can take if you have a lanternfly infestation, but eradicating the species from the state entirely is unlikely to happen
“They are really beautiful,” said Rocky Brockman, “but they’re also really destructive.”
Brockman, an entomologist and horticulturalist at the University of Kentucky’s Boone County Extension Office, was talking about the spotted lanternfly, an invasive planthopping bug that is now officially at home in Kentucky.
When they were first spotted in Northern Kentucky in late 2024, researchers instructed residents to report the pests as they found them. Now, people no longer need to report them. They’re here, and they’re not going away.
“We really expect them to get worse, probably pretty significantly worse over the next few years,” Brockman said. “To some extent, they’re going to be something that we have to learn to work with.”
So, what’s significant about our new planthopping neighbors?
True bugs
Spotted lanternflies are native to east Asia and belong to a category of arthropods called fulgorid planthoppers, included in a category entomologists refer to as “true bugs,” rather than insects, according to Brockman. They were first documented in the U.S. in Pennsylvania, and have since spread to 18 other states and the District of Columbia, according to the U.S. Department of Agriculture.
Using its needle-like mouth parts, the bugs pierce tree bark to suck out the sap underneath. Doing it once won’t kill a tree, but repeated feedings, especially in large groups, will kill a tree over time. Lanternflies seem to prefer fruiting plants, particularly grapes. More than any other plant, however, they’re drawn to another invasive species: the tree of heaven, also native to east Asia.
Trees of heaven grow quickly, and although they can grow quite large, you’re more likely to see dense clusters of smaller specimens in the wild. Adult trees of heaven are distinguished by their gray bark and long, compound leaves with spear-like leaflets. People often describe the shoots and leaves as having a peanut butter-like smell. Tree of heaven flowers develop into red and gold seed pods as they mature.
The flies also expel a sugary, sticky substance called honeydew as a waste product. Honeydew-coated leaves are susceptible to fungal buildup, which is unsightly but usually not deadly to the tree, Brockman said.
As an aside, honey bees can adapt to use honeydew instead of nectar to make honey.
“What I’ve been told is that it gives a different flavor to the honey,” Brockman said. “It is more of a kind of smoky honey.”
Lanternflies were first spotted in Kentucky in Gallatin County in 2023. They actually don’t fly all that far, Brockman said, but they spread by laying their eggs on flat surfaces, which then get transported around.
“The primary way that they have moved around the country is by laying their eggs all over the place,” Brockman said. “The big issue that has happened is they keep on laying them on tires for cars. They’ve also laid them on equipment that has been moved on trains. [In] Gallatin County, where it was originally found in Kentucky, it was found right next to a train yard.”
Adult flies will cover their freshly laid eggs with a waxy protective coating that darkens as it is exposed to the elements. Hatched eggs lack the protective coating and have holes in them where the young bugs, called nymphs, crawl out.
Newborn nymphs are small, have white spots but no wings (although they’re still capable of hopping). As they mature, they gradually take on the flies’ characteristic red color before eventually growing wings and becoming adults. Eggs are usually laid in winter with the first nymphs emerging in late spring and early summer. The nymphs begin to take on their adult traits by July.
What do you do about it?
“We have them at our house,” said Traci Markgraf, who had come to the UK extension office to learn more about the bugs.
Hebron resident Wally Brown also attested to the presence of the bugs at his property and worried how it might affect the plants or if he had to consider removing some of his trees.
“I’m trying to find out what I need to do because it’s right on the border with my neighbor, so I want to talk with him to see if maybe we want to remove the trees together,” Brown said.
Removing trees of heaven, especially since they’re also invasive, is among the more efficient ways to curtail a lanternfly infestation. Given how hardy the trees are, Brockman said, cutting them down isn’t enough; the trunks will simply re-sprout new shoots. Instead, special herbicides to kill the trees at their roots are more effective.
You can also set special traps to catch the bugs, or cover your plants with netting to prevent the lanternflies from landing, although Brockman did not recommend this with younger plants. Pesticides work too, but Brockman recommended being selective and careful in their use. Sticky tape around tree trunks can be used to detect the bugs, but sticky tape will sometimes inadvertently catch other wildlife, including birds. Finally, eggs can scraped off surfaces or smashed.
“My personal expectations is that this will likely get quite a bit worse for probably the next four or five years before it hopefully hits a peak and then starts going down,” Brockman said.
Consult Penn State University’s spotted lanternfly management guide, linked below, for more detailed information on assessing lanternfly populations, treatment methods, insecticide recommendations and more information about lanternfly life cycles and behavior.
You can also reach out to the Boone, Kenton and Campbell county University of Kentucky Extension Offices to talk to experts, not only for info about lanternflies but also horticulture, agriculture, natural resources, consumer science and other community resources below.
