No. 6/June 9, 2014

Oak Leaf Blister
Oak leaf blister has started to appear on oak trees on the Illinois. This disease is caused by the fungal pathogen, Taphrina caerulescens. Members or the red oak group are more commonly affected by the disease. Symptoms are distinctive, and appear as scattered blister-like, puckered, or raised areas on the leaves.

Mushrooms Growing in Turf
Wet spring weather has provided an excellent environment for mushrooms. They can form wherever sufficient moisture and organic matter is present. When found growing in turf, mushrooms tend to stand out and be unsightly to some. The fungi responsible for producing the mushrooms live off organic matter in the soil, such as decaying tree roots or buried construction debris.

Anticipation... of Tomato Diseases
Tomatoes!  We all love them but you need to anticipate that disease issues can quickly arise. Now is a good time to review common disease and environmental issues that may arise with the tomato plants.  Some issues may be in the form of foliar diseases or even environmental mayhem, so it's a good idea to keep in mind some examples of what to look for and what options are available for treatment.

Modified Growing Degree Days (Base 50°F,  March 1 through June 5)
Insect development is temperature dependent. We can use degree days to help predict insect emergence and activity. Home, Yard, and Garden readers can use the information in this article to determine what insect pests could be active in their area.

Invasive Species ALERT: Viburnum Leaf Beetle
We've shared several articles in in the Home, Yard, and Garden Pest Newsletter about the viburnum leaf beetle. Up until the last 2 weeks, we've only had a couple of isolated reports of viburnum leaf beetle in the state, in both DuPage and Cook counties. Over the past couple of days, several reports of severe defoliation caused by viburnum leaf beetle have come in from these same two counties.

Periodical Cicada
Periodical cicadas should be emerging in northwestern Illinois. This is the Iowa brood, also known as Marlatt's Brood III, that covers most of the southern two-thirds of Iowa. It extends into Illinois, being present in Henderson, Warren, Knox, Fulton, and Schuyler counties. It has a disjunct area in northern DeWitt, and northwestern Champaign counties.

Buffalo Gnats
We have received reports of large numbers of buffalo gnats, also known as black flies, attacking people particularly in western Illinois. Buffalo gnats are small, 1/16- to 1/8-inch-long, humpbacked black flies. They bite exposed skin, typically leaving a small, red welt. When the gnats are numerous, the toxins from their bites can kill poultry and other birds.

Bagworms will have hatched in southern Illinois. They should hatch by mid-June in central Illinois. When newly hatched bagworms emerge from their mother's bag, they climb to the top of shrubs, trees, and any other erect object. They spin out two to three feet of silk which catches in the wind and blows them to new locations.