Controlling the European corn borer in Iowa by dusting or spraying with insecticides is sometimes practical. If you are planning to try insecticides, you need to consider the value of the crop, the possible loss where no treatment is applied, the cost of treatment and the availability of materials and equipment.
"Feed Corn Borers Poison,"
Iowa Farm Science: Vol. 1
, Article 3.
Available at: https://lib.dr.iastate.edu/farmscience/vol1/iss8/3