Corn can withstand a considerable amount of whorl damage. When infestations are heavy enough to cause dead-heart or severe stunting of plants, yield loss may occur. When worms infest young plants, two to three feet in height, they may kill the center of the plant and on seedlings, death of the whole plant may occur. To determine the infestation level, check corn whorls for worms. Control is justified when you find three to six worms per plant.
Several insecticides are effective.
It is important that the insecticide be directed down into the whorl of the corn by using a high volume of spray material. Thus, ground applications of sprays are usually much more effective than aerially applied sprays. European and Southwestern Corn Borers - Detailed information on European and southwestern corn borers can be found on the corn borer insect management web page. Chinch Bugs - Chinch bugs occasionally attack corn and may cause severe stunting and yield reductions. Chinch bugs are routinely a problem in certain areas of the state and intensive management may be required to control this insect.