'Just A Matter Of Time' Before Spotted Lanternfly Lands In IL: Expert

ILLINOIS — A one-inch spotted insect that has already made the Most Wanted List among state agricultural experts could be headed to Illinois in a matter of time after being spotted recently as close as Indiana.

The spotted lanternfly is native to China but has made its presence known in the United States over the past decade. And the insect that has crept west from Pennsylvania since 2014 and that has the potential to do serious damage to the state’s fruit trees may eventually make its way to the state and even to the greater Chicago area, a University of Illinois expert told Patch on Tuesday.

Lanternflies spend the winter in the egg stage as adults and juvenile versions of the insect can’t survive prolonged freezing, Chris Dietrich, an Illinois State entomologist wrote in an email. But the bugs that tend to feast on the tree of heaven along with grapes, fruit trees, and also black walnut trees could be considered a threat in Illinois — even before the pesky bugs have made their way here, Dietrich said.

The spotted lanternfly has continued to make its way west in a number of ways. Because eggs are laid on various surfaces including vehicles, trailers, camping equipment, and firewood, they are easily moved from place to place inadvertently, Dietrich said, and this is probably the main means of spread in the United States so far.

Once the spotted lanternfly makes its way onto plants, it can "reduce the vigor" of plants and cause dieback on the plant's branches, the University of Illinois Extension office said earlier this year.

“This insect is definitely a threat, as can be seen by the damage it is causing in areas of the mid-Atlantic where it has become well established,” Dietrich wrote in an email. “However, I think it remains to be seen how extensive and persistent the threat will be and how much damage it might cause farther west.

“Certainly, people who manage vineyards, orchards, and tree nurseries have cause for concern. The extent to which the lanternfly poses a threat to mature forests is still not entirely clear but it’s best to be cautious at this stage.”

Dietrich said that while fruit trees and other species are most at-risk, the spotted lanternfly is “very tolerant” of human-altered habitats, which gives them the potential to do “just fine” in a large urban area.

Given the number of people driving their campers and other vehicles home to the city from a summer vacation in the east, local residents can easily transport them home and when the eggs hatch the next spring, the baby lanternflies can feed on a variety of trees and shrubs that people may have planted in their yards.

However, despite the threat the spotted lanternfly can cause, Dietrich and other experts warn residents that the bugs should not be killed if spotted. Instead, encourage residents to take photos of the insects and send them to the Department of Agriculture by email at lanternfly@illinois.edu. Residents may also call the agency at (815) 787-5476.

“A single individual lanternfly generally isn’t going to do much damage unless it’s a female that hasn’t yet laid her eggs,” Dietrich said. “When you see one, that is usually an indication that there are more present that you’re not seeing, so killing single individuals probably isn’t particularly effective at preventing their spread.”

Dietrich said that spotted lanternflies seem to disperse slowly when left to their own devices, but they are very effective hitchhikers because the females deposit their egg masses on many different surfaces (usually on tree trunks but also on cars, trucks, trailers, firewood and camping equipment). The eggs normally survive the winter and give rise to a new generation in the spring.