Common Tree Diseases Found In Central Illinois

Common diseases


Anthracnose is a fungal disease that affects many types of deciduous trees. Ash, Oak, Sycamore, Maple and Birch are a few of the tree species commonly affected by Anthracnose. Leaves infected with Anthracnose are often spotty, especially along the veins and with brown, curled edges. Infected leaves sometimes drop.
Black Knot is a common fungal disease seen in the Prunus family, which includes plum, cherry and wild black cherry trees. The disease is characterized by large, hard black swellings on branches that cause branch dieback.
Apple scab is a fungal disease that commonly affects trees in the rose family including crabapple, pear and apple trees. Leaves infected with Apple scab often turn spotty, yellow and drop prematurely. Trees are sometimes totally defoliated by mid-summer. Apple scab infections seem to be worse during wet, rainy springtime weather.
Cedar- quince, cedar-hawthorn and cedar-apple rust are fungal diseases that are found on a variety of hosts including crabapple, hawthorn, mountain ash and serviceberry trees with junipers being the alternate host. On the deciduous host orange or rust colored spots form on leaves while fruiting bodies and galls form on the junipers.
Dutch elm disease is a fungal disease that is spread by elm beetles and through root graphs from surrounding infected trees. Elms infected with Dutch elm disease show symptoms that include wilting, yellow, curling leaves in the outer canopy.
Verticillium Wilt is a soil borne fungal disease that affects hundreds of different kinds of plant species. Many trees are susceptible to Verticillium Wilt with Maples, Ash, and Red Buds being more commonly affected. Sudden wilting of branches or sections of trees with staining of the sapwood are symptoms of Verticillium wilt.
Bacterial Leaf Scorch is a disease that appears on a variety of deciduous trees including oaks, maples, sweet gum, and mulberry trees. Once infected with the bacterial infection trees will develop scorch symptoms in the summer months and dieback slowly over the course of ten years.
Oak wilt is a fatal disease among the oak species, with Red Oaks being the most commonly and acutely affected. The symptoms, which usually appear in mid-summer, are sudden leaf wilting, browning and premature leaf drop. Leaves will often turn a bronze color before dropping.
Fireblight is a common bacterial infection seen in trees in the Rose family, with the ornamental pear the most commonly affected. Leaves and stems appear to be blackened or scorched at the ends of branches, hence the name fireblight.
Diplodia Tip Blight is a fungal disease that is often seen on hard pines. Stunted, oozing, browning needles and branch tip dieback are common signs of infection. Black fruiting bodies can be seen on dead needles.
Dothistroma is a fungal disease seen on pines in the Midwest. Tips of needles turn light green, then tan and then brown. Reddish brown spots or bands are often seen on infected needles.
rrhizoPine Wilt is a fungal disease that affects all pines, with the exception of the white pine. The fungus enters the tree when it is attacked by the Sawyer Beetle who is a carrier of a nematode. The nematode is the actual host of the fungal disease, not the beetle. Pines infected with Pine Wilt will suddenly brown up and die in a short amount of time.
Cytospera Canker is a slow moving fungal disease commonly seen on older Spruce trees among other conifers. Cankers form on the branches and trunks. Needles turn brown and drop, usually starting at the ends of branches, working inward. Often the disease starts on the lower branches and progresses upward, killing branches on one side.
Rhizospaera Needle Cast is a fungal disease most commonly seen in Spruce. Other conifers such as pines and firs can also get the disease. Infection usually starts on the lower branches of the tree and progresses upward. After infection, needles turn yellow late in the summer. During the following winter or early spring the needles then turn anywhere from brown to a brownish purple color before beginning to drop.