No. 8/June 15, 2015

Potato Leafhopper
Potato leafhoppers are actively feeding with damage being obvious on red maple. These leafhoppers attack oak, maple, red mulberry, red bud, cottonwood, birch, apple, dogwood, hawthorn, wafer ash, euonymus, black locust, and cherry.

Regulated Weeds
The State of Illinois has two "legal" lists of problematic plants that require attention – Noxious Weeds and Exotic Plants. Both will be discussed in this article.

Modified Growing Degree Days (Base 50°F, March 1 through June 4)
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 links in this article with the degree day accumulations listed to determine what insect pests could be active in their area.

Invasive Species Updates
Updates are given regarding viburnum leaf beetle, emerald ash borer, and gypsy moth.

Chlorosis of Woody Plants
Chlorosis is a yellowing of leaves that should normally be green. This is due to a lack of chlorophyll, causing the tissue to lose its bright green color. Usually the veins will stay a dark green while the leaf tissue turns lime green, then in severe cases, yellow. Necrotic (dead) areas may appear if the chlorosis continues without being treated.