Unlike the corn earworm, the fall armyworm feeds by burrowing through the husk on the side of the ear. Larvae also enter at the base of the ear, feeding along the sides and even tunneling into the cob. They usually emerge at the base of the ear, leaving round holes in the husks.
Scout to determine if insecticide treatment may be necessary. Economic threshold – when 75% of plants show whorl injury, plants stressed and larvae less than 1 ¼ inch long.
Bessin, R. 2004. Fall Army worm in corn. University of Kentucky Entomology Factsheet ENTFACT-110. Available at https://entomology.ca.uky.edu/ef110 [URL verified 3/28/2019].