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Invasive Species

A tree grows everywhere: Tree-of-heaven image of woodlands full of young trees end of summer

A tree grows everywhere: Tree-of-heaven

Two separate serendipitous events occurred recently that brought a plant back to the forefront of my attention. First, a few weeks ago a colleague asked me to confirm the species of a tree growing near a public garden. The garden was struggling to grow, and a cursory identification of the tree...
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truck hauling firewood

Emerald Ash Borer: Is it okay to move firewood yet?

Many years ago, when emerald ash borer (EAB), had just arrived in northern Illinois, a colleague came across a flatbed trailer loaded with cut ash trees at a gas station. At that time Illinois counties confirmed with EAB had a quarantine that restricted moving ash wood outside of the county. Most...
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Jumping worm

Invasive jumping worm confirmed in west-central Illinois

How full is your invasive species radar? All I can say is my view is overwhelmed. Dealing with the current group of Japanese beetles, emerald ash borer, bush honeysuckle, and so many more. Plus, in Illinois, we are girding for the impending arrival of the very destructive spotted lanternfly. Then a...
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low burning fire goes through forested area

A legacy of stewardship at Allerton Park

In 1946 Robert Allerton transferred the ownership of a large parcel of his estate near Monticello to the University of Illinois. The Allerton legacy gift is now used as a public park, a conference and retreat center, and a 4-H youth camp.  Now, 75 years later, nearly all of its 1,600 woodland...
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black beetle on cut surface of wood with holes in it

Invasive Asian longhorned beetle threatens forests

The Asian longhorned beetle is a non-native pest that threatens a number of hardwood trees in North America. The larva damage living trees as they tunnel through. History of Asian Longhorned Beetle The Asian longhorned beetle was first identified in New York City in 1996. It is believed that this...
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oak tree affected by Phytophthora ramorum pathogen

Pathogen that causes Sudden Oak Death found in Illinois

In 2019, the pathogen that causes Sudden Oak Death, a plant disease that has killed large tracts of oaks and affected many native plant species in California, Oregon, and Europe, was found in Illinois.  Phytophthora ramorum, the causal agent of Sudden Oak Death (SOD) was confirmed in...
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palmer amaranth

Invasive Palmer amaranth threatens Illinois crops

Palmer amaranth is an invasive weed species we have been hearing a lot about in agriculture over the last 10 years, and it continues to be a threat after its first documented appearance in Illinois in 2012. Native to southwestern US states, palmer amaranth has made its way to 39 of the states....
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removal of infected boxwoods

Boxwood Blight look-alikes

With the recent detections of boxwood blight, which is a regulated plant disease, in Illinois, the importance of scouting landscapes and new plants for the disease is greater than ever. Boxwood blight can be a challenging disease to identify outside a plant diagnostic laboratory. Many of the...
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winged euonymus fall color leaves

Three common landscape shrubs you didn’t know were invasive

When we look at the current lists of plants that are deemed legally invasive by state and federal governments, we see species that were quite popular in the landscape in generations past. As we battle the current invasive species in our natural areas, there is a new generation of non-native shrubs...
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