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Fall Armyworm

This pest is technically a cutworm, but due to its habits and the extent of damage that it sometimes causes, the fall armyworm is generally mentioned separately. These insects are found in our various crops almost every year. The larvae will feed on corn foliage, stalks, and ears. They may even tunnel into the cob.

A fall arymworm larva. Photo: Clemson University CE Series 42-2931CThe fall armyworm is not known to overwinter in South Carolina. Therefore, it must immigrate into the state each year. This being the case, it is seldom a problem until later in the season, when populations have had sufficient time to build up. For this reason, corn that is planted early and harvested early will be exposed to this pest for a much shorter time, thus reducing losses due to this insect.

The favorite foods of the fall armyworm are native grasses such as Bermuda and Johnsongrass. It usually attacks cultivated crops only after these preferred foods have been devoured. Then they may mass together and “march” in “armies” to nearby crops. Grass attracts the moths as well, so keeping grass under control until the corn starts to mature is another valuable cultural practice that should be employed.

Since the list of labeled products is constantly changing, and since available products varies from state to state, there will be no mention of specific products. When a rate range is given with these products, the lower rate should be used on small corn. In all cases, the insecticide should be applied to give good coverage of the entire plant if control is to be expected. With all insecticides, read and follow all label instructions carefully.


Prepared by Donald G. Manley, Extension Entomologist/Professor, Department of Entomology, Soils, and Plant Sciences, Clemson University.


This information is supplied with the understanding that no discrimination is intended and no endorsement by the Clemson University Cooperative Extension Service is implied. Brand names of pesticides are given as a convenience and are neither an endorsement nor guarantee of the product nor a suggestion that similar products are not effective. Use pesticides only according to the directions on the label. Follow all directions, precautions and restrictions that are listed.

The Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, sex, religion, national origin, disability, political beliefs, sexual orientation, marital or family status and is an equal opportunity employer. Clemson University Cooperating with U.S. Department of Agriculture and South Carolina Counties. Issued in Furtherance of Cooperative Extension Work in Agriculture and Home Economics, Acts of May 8 and June 30, 1914.