What’s bugging you? Spotted lanternfly proves hard to control

“The future with them is certainly unsettled at this point, but you can be sure they are going to spread as far as they possibly can with massive populations wherever there are plants to support it,” Roulston said. “Especially if there are lots of trees of heaven available.”

Besides their native food, the bugs flock to grapevines, maple trees, walnut and butternut trees. They bore into bark to suck the sap and excrete a sticky substance euphemistically known as “honeydew,” which can coat decks, swing sets, driveways and vehicles.

While not harmful to humans, the sweet substance attracts other insects and feeds the growth of “black sooty mold,” a group of fungi that thrives on the sugary secretion. The mold may also cover leaves and branches and inhibit photosynthesis, additionally stressing trees and plants.

Like the brown marmorated stink bug before it and the gypsy moth before that, the spotted lanternfly population will likely be greatly reduced from a plague to a pest in the next few years, Roulston said. The question is when.

“We’re still waiting for something to control its population. So far, there really aren’t any parasites that are effective on it, and there are no real predators at this point. It is a massive opportunity for the first organism that figures out how to eat it,” Roulston said. “Anytime you see that much food in one place, something in nature will discover that it tastes good.”

T’ai Roulston studies invasive species at UVA’s Blandy Experimental Farm research institute near Winchester. He says other than taking down the spotted lanternfly’s favorite food tree, not much can be done about the bugs without harming other creatures. (Contributed photo)

Roulston noted reports showing praying mantises and some spiders eat the lanternflies, but they haven’t made the spotted invaders regular meals, yet.

“There are reports, but if it really was much of a food for any of these organisms, you would see your trees covered in spiders or praying mantises or, you know, whatever,” he said.

Until then, there is little you can do to prevent the invasive sap suckers from gathering by the hundreds, and no one is recommending spraying large quantities of pesticides that could kill bees, butterflies and other insects.

“Depending on what kind of tree you’re trying to protect and what time of year, there are going to be different possibilities and different effects on other organisms,” Roulston said. “If you’re trying to save a particular tree, systemic pesticides injected into the tree are an option. That will only directly affect things that are feeding on the tree.”

Sticky traps are not recommended, as they can snag birds and mice, as well as beneficial insects. Removing trees of heaven, as the arboretum has done, may help. Even a “circle trap” around a tree’s trunk can reduce the number of spotted lanternflies feeding on a tree.

“Spotted lanternflies usually land fairly low on the tree trunks and then crawl up,” Roulston said. “You can put this mesh skirt around the tree that catches the insects going straight up the trunk. They end up inside the mesh and will not make it further up. It’s not foolproof, of course, but you can reduce the number of spotted lanternflies on the tree.”