Unusual Armyworm Outbreaks are Taking Many by Surprise

By Kelley Tilmon and Andy Michel et.al

We have received an unusual number of reports about fall armyworm outbreaks particularly in forage including alfalfa and sorghum sudangrass, and in turf. Certain hard-hit fields have been all but stripped bare (Figure 1).

Figure 1. Fall armyworm feeding damage. Photo by James Morris, OSU Extension

True or common armyworm is a different species than the fall armyworm. The true armyworm is the species that causes problems in cereal crops in the spring of the year. Fall armyworm migrates into Ohio during the summer and could cause problems into late summer. It is not or maybe we should say has not typically been a problem in Ohio. Also, unlike the true armyworm that only feeds on grasses (i.e., corn, wheat, forage grasses), the fall armyworm has well over 100 different types of plants upon which it feeds including many grasses but also alfalfa, soybeans, beets, cabbage, peanuts, onion, cotton, pasture grasses, millet, tomato.