No. 8/June 12, 2009
Scouting Watch
Emerald ash borer, bagworm, spruce spidermite, and twospotted spidermite are discussed.
Japanese Beetle
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.
Crayfish
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
"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.