Corn Borer

Corn Borer: June - August

Selecting a county that is colored in on the map will show a graph of this year’s catches at the site.

Adam Sisson, Iowa State University,

Corn Borer is a non-native species and has been a substantial pest to the Midwest since the 1920s.

Corn Borer, Ostrinia nubilalis Huber, over-winters as a fully formed larva in plant residue left behind after harvest. In the spring, larvae pupate and present as moths in late May and early June.

Like other pests, Corn Borer can have multiple generations within a growing season. The first generation will bore into whorls of leaves and then move down the stalk as they age,

boring into it. This can leave the corn plant to weaken, resulting in stalk breakage and/or yield loss. Boring can also lead to pathogens entering the plant and causing stalk rots later in the season. The second generation may cause the corn plant to experience stalk or tassel breakage, and/or causing ears to drop off from boring into ear shanks.

Management of Corn Borers can be economically taxing but might be necessary if severe. Other ways to avoid Corn Borer damage include planting hybrids with genetically introduced Corn Borer toxins.