April 9, 2008
At this time, there is no need for insecticide treatments for emerald ash borer anywhere in Iowa. The emerald ash borer (EAB), Agrilus planipennis, has been found 85 miles from Iowa in Peru, IL. As EAB moves closer to, and into Iowa, this recommendation may change as we learn more about the known infestation areas and the ever-changing status of control options. But for now, any application of insecticides to ash trees for EAB control is a waste of time, money and resources.
The rationale behind this position is as follows:
The ISU Plant and Insect Diagnostic Clinic recently received a Scots (Scotch) pine sample with galls typical of pine gall rust. Although this disease is not especially common in Iowa, it appears occasionally, especially in Christmas tree plantations growing susceptible Scots pines.
We have received several samples from evergreens showing symptoms of "winter browning." Winter browning results from a combination of freeze/thaw cycles, rapid temperature changes, and cold temperatures as evergreens continue to lose water as they photosynthesize over the winter.
Cauliflower is one an underappreciated vegetable in the garden. I sometimes wonder why more people don't grow this member of the broccoli family.