An invasive insect has made its way into Illinois, and it has horticulturists and industry groups watching closely.
Spotted lanternfly (Lycorma delicatula) is a leafhopper that’s native to eastern Asia. It causes damage to a variety of fruit, ornamental and woody trees by feeding on the sap. It can cause damage to the grape and logging industries in the state but is not a threat to humans or animals. They were first detected in the U.S. in Pennsylvania in 2014 and have recently spread to Cook County. The lanternflies are problematic for plants because they release a secretion known as “honeydew” (nothing to do with the melon). These secretions can cover the ground under trees and coat leaves, blocking sunlight and preventing photosynthesis.
Emily Swihart, Illinois Extension Horticulture Educator for Henry, Mercer, Rock Island and Stark Counties, says it’s important to keep an eye out for these insects. “There’s concern because they are a sap sucking insect. It’s not native to North America, so there’s no natural predation for the insect. When there is no natural predation happening, there’s nothing that is prone or is naturally feeding on these, so the sap sucking insects are going to be feeding on the stems and branches and the trunks of woody plant materials.” While this isn’t fatal to the trees, it can reduce their vigor so they won’t be as healthy and may become susceptible to other types of decline.
Even though the lanternflies have just gotten to Illinois, experts have been watching them for some time. “We do a lot of educational programs throughout the year, especially at our state convention so we’ve been following the lanternfly for several years now,” said Ryan Phelps, vice president and viticulture chairperson of the Illinois Grape Growers and Vintners Alliance. “Apparently, it just landed, or they just spotted it in Cook County, so we’ll keep monitoring that and we’ll monitor our local vineyards.”
People who think they’ve found a spotted lanternfly should send an email to lanternfly@illinois.edu with photos of the egg casings, adults or the nymphs. Then the lanternflies should be destroyed by crushing them or scraping the egg casings off the surface and placing them in rubbing alcohol or hand sanitizer. The bugs themselves should not be moved. People who live in or visit an infested area should check their vehicles regularly to ensure they’re not inadvertently helping the spread. Females are laying egg cases at about this time of year, so it wouldn’t be uncommon for them to lay cases on a vehicle, which can spread them further.
One way to stop the spread of spotted lanternflies is to make sure they’re not hitching a ride on your vehicle or anything you haul. “Check the materials that you’re moving,” says Swihart. “That includes your car and your person, so just be alert to it.”
Limited their food supply is another way to stop the spread of spotted lanternflies. “The insect particularly loves another invasive species, Ailanthus altissima, more commonly known as the Tree of Heaven,” said Swihart. “You can look for and remove those species from your landscape to try to minimize the preferred food sources.” Unfortunately, there’s one tree these bugs enjoy that’s a huge part of the local landscape. “It also really likes maples and so that’s problematic because we have a lot of beloved maples in our landscape.”
Doing basic gardening chores like cleanup is an effective way to keep spotted lanternflies away from your property, says Phelps. “If you’re looking at a personal property, getting rid of wild grapevines (and) an invasive tree called Tree of Heaven that they feed on quite extensively is a good thing.”
While the details might sound alarming, there’s no cause to panic. “It’s mostly going to be a nuisance, but we certainly want to be alert for it,” said Swihart. “This is an emerging issue for us. It’s relatively new even to North America, so I would encourage people to stay alert both in their own landscape and then, as news comes out or as research develops, continue to be citizen science advocates and participate in helping us minimize the spread.”
While Phelps usually works with larger vineyards, he has advice for home gardeners with a few grape vines of their own. “Monitor your grapevines in Illinois. It’s a good idea to get on a spray program because we have a lot of fungal issues.” He cautions residents that they shouldn’t go overboard with spraying. “Don’t just spray to prevent. When it comes to insects, there are some beneficial insects. Ladybugs eat aphids, ladybugs are good to have around so we wouldn’t suggest a broad-spectrum spray program for insects.”
“It’s a serious pest for the industry and for the native plants,” said Phelps. “The Department of Agriculture will have a lot of information on it. If you do see something that you think might be one, take a picture and send it in.” Ag groups will track the lanternflies’ movement county per county as they spread out of Cook County.
For more information on the spotted lanternfly, including photos of development stages, click here.
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