The volunteer Master Gardeners around the state are also tracking the spread of the bug using sticky tape to trap the insects as they climb up trees of heaven – which are also called ailanthus or paradise trees.
The insects are native to China, India, and Vietnam, but moved into Korea in 2006, where it attacked more than 60 different plant and agricultural crops. In 2014, it was found in the U.S for the first time in Bucks County, Pennsylvania. Despite best efforts to control it, it has since moved into more than 15 Pennsylvania counties as well as Delaware, New Jersey, New York, and Virginia.
One of the challenges with containing the spotted lanternfly is the ease with which it can spread. In addition to host plants, it lays eggs on concrete, rocks, wood pallets, and vehicles, which are then moved around the state. When spotted lanternfly eggs and dead adults were discovered in Winchester, Virginia, earlier this year, they were located adjacent to a railway and highway. The egg masses began to hatch in May.
“They were found in a spot that creates a perfect storm,” Day said.
The lanternfly feeds on the tree of heaven because the chemical that gives the tree its distinct, pungent odor, also makes the insect taste bad when birds eat it. This taste makes birds less likely to eat the insect a second time.
Merely cutting down the trees of heaven to detract the spotted lanternfly doesn’t help. They will grow back up from the roots, often in bigger numbers, creating more feeding opportunities for the lanternfly. Researchers are looking into ways to control the trees of heaven.
Beyond the trees of heaven, the spotted lanternfly will also feed on more than 70 other host plants, including a wide range of agricultural crops.
When the spotted lanternfly is feeding on a plant, it secretes what is known as honeydew, a black, sticky, stinky substance that coats the plant and can cover the ground below. This promotes fungal growth, damaging the plants and attracting other insects. Grape growers have reported that yields have decreased from 4.5 tons per acre to about a half ton per acre after the lanternfly attacked the plants.
Officials are calling on people around the state be vigilant and report any sightings of the insect.
“We don’t know how bad it can get with this invasive insect,” Day said. “But the more we can learn about its movement, the better we can control it.”