Insect outbreaks depend a lot on the weather that occurs during the crop season. Temperature, rainfall, soil moisture and humidity are all important. Depending on weather, here's the forecast for 1959.
Gunderson, Harold and Raun, Earle S.
"Insect and Rodent Prospects for 1959,"
Iowa Farm Science: Vol. 13
, Article 4.
Available at: https://lib.dr.iastate.edu/farmscience/vol13/iss7/4