No. 8/June 12, 2009
Emerald ash borer, bagworm, spruce spidermite, and twospotted spidermite are discussed.
Japanese beetle adults were picked up in a trap in Massac County on June 7 by Ron Hines of Growmark. Based on that, we are expecting adults to emerge in central Illinois by about June 21 and around July 5 in northern Illinois.
The heavy rains throughout much of Illinois have created ideal conditions for crayfish to be more of a problem in turf. Crayfish have gills that require constant moisture. Rainy nights and standing water allow the migration of these insect relatives across land to new locations.
"Oak tatters" is a term coined for a condition that has occurred for at least 20 years in Illinois. The foliage appears to have been eaten by an insect, leaving only the major veins and a bit of tissue around the veins remaining intact.
Cankers--Botryosphaeria and Others
Cankers are dead areas on plant stems. They may appear sunken, shriveled, off-color, bumpy, or even wet. Pathologists can tell you the fungus (or bacterium in some cases) associated with a particular canker, but the canker would not occur without a mechanical injury or some form of plant stress.
Is Verticillium Wilt Killing My Tree?
Verticillium wilt is a name that is associated with sudden death of mature trees, shrubs, perennials, and vegetables. In Illinois, this fungal disease may be caused by either Verticillium dahliae or Verticillium albo-atrum.