Spotted Lanternfly Spotted in Illinois

Invasive species are putting continual pressure on plants and animals in Illinois, which is only expected to intensify in the coming years. This means we all need to be vigilant for new threats and aware of their impact when new invasives arrive.

On September 16, 2023, experts confirmed the arrival of a new invasive species in Illinois with the first documented occurrence of the spotted lanternfly (Lycorma delicatula). That insect was located in Cook County. Officials across the Midwest have been monitoring for this pest since its first detection in the United States (Pennsylvania) in 2014, with expectations it will spread.

“Illinois is known for having many high-risk transportation pathways, such as railroads, highways, airports and marinas, so it is not overly surprising that this pest has showed up in a population center,” noted Tricia Bethke, Forest Pest Outreach Coordinator at The Morton Arboretum.

Bethke, along with other experts from the Illinois Department of Agriculture, the City of Chicago Bureau of Forestry and USDA’s Animal and Plant Health Inspection Service (APHIS), has been actively involved in searches for the pest, as well as responding to new inquiries about this alien insect.

A New Pest

The spotted lanternfly is a tricky pest to contain due to its habit of laying eggs masses on a variety of smooth, human-made surfaces. From railcars to campers and boats, it tends to deposit eggs on things that humans move around, and we can unknowingly be the vector of spread across great distances.

Word has also spread of this new infestation as the spotted lanternfly made headlines upon its arrival.

“The public has been more curious than alarmed, and our message of ‘Don’t Panic’ has been a big relief,” said Bethke. Her wise words offer some solace in the face of this new threat to Illinois. It is not a time to panic, but a time to be vigilant.

Bethke reiterated her mantra, ‘See it, snap it and send it to lanternfly@illinois.edu.’

We want to document the spread by county,” she explained. “Cook County has been verified, so we encourage residents throughout the state to keep looking and reporting if they suspect an infestation.”

With a continual stream of new research coming from the areas of initial infestation, researchers are sharing lessons learned on the impacts of this pest, as well as management strategies. These tools have painted a clearer picture of what the arrival of the spotted lanternfly may mean to new areas.

Non-native Taste

“The spotted lanternfly has a wide host range and is expected to feed on quite a few landscape plants, but it is not going to wipe out your yard,” noted Bethke.

She also mentioned this pest’s affinity for another non-native from the plant kingdom: “Tree-of-heaven is its preferred food source, and this presents a positive side of this particular pest, since tree-of-heaven is a problem plant.”

Tree-of-heaven is a fierce competitor when it invades natural areas as it spreads via an aggressive root system and prolific seed production to out compete native plants,” she continued. “This aggressive habit has also led to extensive spread in urban areas as well, with many noting this plant as tough enough to grow in ‘the cracks of sidewalks.’”

Dense populations of tree-of-heaven will attract spotted lanternflies and one great recommendation to limit the spread of this insect is to control tree-of-heaven, and to do so now.

“Remove unwanted invasive plant material around trees and buildings,” recommends Bethke. “The spotted lanternfly is a planthopper so, when there’s nothing to hop on the likelihood of spread diminishes greatly.”

For information on management of tree-of-heaven, see the Illinois Nature Preserve Commission’s Vegetation Management Guideline. Also review the Illinois Department of Agriculture pesticide use and regulation website as a license is required for persons applying pesticides to property they do not own or control. In addition, a higher class of license is required to purchase some chemicals.

Bethke also noted that the spotted lanternfly has shown an affinity for other species, including wild grape (Vitis spp.), willows (Salix spp.), birches (Betula spp.), and both red (Acer rubra) and silver maple (Acer saccharinum).

What’s Next?

When asked about the future of the spotted lanternfly in Illinois, Bethke replied with a positive message.

“The future looks pretty good,” she proclaimed. “We have great partnerships and communication channels and hope to get ahead of any high-level infestations. We took a team approach to identifying, documenting and managing this pest, and it worked!”

“Panic levels are low, people are reporting suspicious pests and we have the tools to learn more about how to identify and control spotted lanternflies.”

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Ryan Pankau has more than two decades of experience as a forester and arborist, building his lifelong love of trees into the career he enjoys today. Beyond trees, he has also focused on integrating the concepts of ecology into the management of plants in the built environment to create more resilient landscapes that better support the native flora and fauna of Illinois. He is currently a Horticulture Educator for University of Illinois Extension serving Champaign, Ford, Iroquois and Vermilion counties.

Tricia Bethke is the Forest Pest Outreach Coordinator at The Morton Arboretum.