Corn earworms are variably colored worms that feed mostly on ear tips. Protect ears with an insecticide from early silking to harvest. Soil insects include wireworms, white grubs, cutworms and seed corn maggots. They are especially troublesome on grassland to be planted to sweet corn. Diseases Stewart's wilt is caused by a bacterium, carried and transmitted by the corn flea beetle.
Prevalence varies from year to year depending upon the number of beetles surviving the winter.
Stewart's wilt is usually more severe on smaller, early maturing varieties. For these varieties, flea beetle control is very important. Common smut is a fungus disease characterized by whitish galls usually erupting from ear tips around silking time. There appears to be some varietal resistance to this disease. The varieties recommended in this guide provide a good measure of resistance to common smut.