It's easy to overlook damage done by "soil insect" pests, and control recommendations haven't always been too satisfactory. This situation is changing; insecticides are proving effective againt these parts.
Lilly, J. H. and Gunderson, Harold
"Insecticides for Soil Insects,"
Iowa Farm Science: Vol. 7
, Article 7.
Available at: https://lib.dr.iastate.edu/farmscience/vol7/iss9/7