No. 9/June 30, 2014

Thousand Cankers Disease
This past week, specialists from the University of Illinois attended a Thousand Cankers Disease (TCD) workshop in Knoxville, TN. The workshop provided updated information on TCD as well as tours of "Ground Zero", the first areas in the Eastern U.S. to have confirmed the disease in black walnut.

Lesser Known "Weeds" -- Elderberry
Elderberry is quite common.  It can be found in every Illinois' county and is in bloom now in central Illinois.  Although this is a commonly seen species (especially when in bloom), many are not familiar with this native perennial shrub.  It grows from 5 to 10 feet tall and has fairly large (4 to 6 inch) flower clusters of small white flowers that form flat, compound umbels.

Modified Growing Degree Days (Base 50°F,  March 1 through June 26)
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.

Sampling for Tree Diseases?  You're Barking up the Right Tree!
Proper sampling of woody tissue for fungal vascular disease diagnosis can save you a lot of time (and money!)  If you have a tree with a problem that you want diagnosed by the University of Illinois Plant Clinic, or another diagnostic clinic, there are the some things you should know before climbing up that ladder.

Last Weekly Issue
This is the last weekly issue of the Home, Yard, and Garden Pest Newsletter for this year. Weeds, diseases, and insect pests tend to be more prevalent in the spring as the frequent rains provide moisture for weed seed germination and fungus disease development. The warming temperatures and growing plants result in a sequence of insect pests as well.

Conifer Sawflies
The most common sawfly that attacks needled evergreens in Illinois is the European pine sawfly, which is present as damaging larvae in the spring. Less common in Illinois, but more devastating in high numbers, are the later-appearing redheaded pine sawfly and white pine sawfly. The larvae of these insects are present from summer into fall, with high populations eating all the needles off branches or entire trees, resulting in the death of branches and trees.