The fall armyworm migrates each year from the south. Damage to corn is similar to that from the common armyworm, although the fall armyworm will also attack the ear due to the timing of outbreaks. The potential for significant outbreaks on field corn occurs about every 5 to 10 years when weather conditions are favorable to the annual migration. During such times, late-planted corn is affected most severely, and infestations may be expected from late July through August.
Fall armyworm is more difficult to control than the common armyworm.