Last year, I was trained to be a "first detector" on emerald ash borer, thousand canker disease on walnut and Oriental bittersweet by the University of Illinois Plant Clinic in Champaign. Being a first detector trainee, I learned what invasive issues (insects, plants or pathogens) to look for in the landscape and forests of Illinois. In addition, experts from the Department of Agriculture, Southern Illinois University and University of Illinois talked about the latest research and news and control strategies.
Emerald ash borer has killed or prompted homeowners to remove ash trees for the last several years in McLean County. The impacts of this pest are all around residents of Bloomington-Normal and well-known here. However, southern and western Illinois counties have not yet detected this devastating invasive insect and are learning from their Illinois neighbors. Woodford County has yet to detect emerald ash borer. In the class, we saw samples of afflicted trees, the insects in viles and even had to identify an ash tree next to look-alikes.
Thousand canker disease has not been detected in Illinois but is as close as Ohio and Tennessee. Thousand canker disease is a fungus spread on walnut trees by walnut twig beetles, and is native to the western United States. The fungus causes patches that look like a mosaic pattern under the bark. When the beetle feeds on the tree, the fungus is spread and blocks the tree's ability to transport water and nutrients. The first signs are wilting and yellowing branches, then dieback and then fast death. The best way to prevent the spread of this disease is to stop the spread of firewood.
Oriental bittersweet commonly can be confused with American bittersweet. But American has fruit capsules that are all orange; Oriental has capsules that are yellow on the outside. American bittersweet has fruit only on the tips of the branches, while on the Oriental bittersweet the fruit is all along the vine. Because Oriental bittersweet is so prolific, chemical sprays are deemed more effective than hand pulling in eliminating them. Hand pulling disturbed the seed bank and left pieces of the roots behind.
McLean County Extension is hosting first detectors training from 9 a.m. to 3 p.m. Feb. 26 at the 1615 Commerce Parkway office in Bloomington. This year brown marmorated stink bugs will be highlighted. They are potential threats to gardeners, farmers and naturalists. Register at https://web.extension.illinois.edu/registration or call me at 309-663-8306. A $40 nonrefundable registration fee covers instruction, lunch and training materials.