To determine the infestation level, check corn whorls for larvae. Control is justified when you find three to six larvae per plant. Corn earworms are cannibalistic and will often eat each other or other caterpillars in the whorl. Generally, only one or possibly two corn earworms will be found in a whorl. If several are found, they are most likely fall armyworms or European corn borers as these species are not cannibalistic.
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. Apply insecticides when 3 to 6 larvae are found per whorl. Use insecticide as a coarse spray in 15 or more gallons of total volume per acre. Back To Top Chinch Bugs Chinch bugs occasionally attack corn and may cause severe stunting and yield reductions.