Cutworm damage can easily be confused with damage from other common corn insect pests. After identifying cutworm species, differentiating cutworm from other pests can help you hone in on effective management strategies.
What does cutworm damage look like compared to other insect pest damage?
Cutworm damage
Cutworm larvae begin feeding in spring and continue until early summer, with peak damage from mid-June through mid-July. Cutworm larvae begin feeding on leaf tissue, resulting in irregular holes in plant tissue. Fourth instar (about half-grown) cutworms can severely injure or cut stalks completely by feeding at the base or below ground.¹
Different species of cutworm can cause damage at different parts of the plant.
Corn rootworm damage
Corn rootworms damage corn at larval and adult stages, with peak damage occurring mid-June through mid-July. Larval rootworm damage includes brown root tips that are tunneled into and/or chewed back to the base of the plant. Plants yellow and wilt, and severe root damage can cause lodging. Around the R1 corn growth stage, adult beetles feed on corn silks. In severe infestations, leaves may be chewed.
Common stalk borer damage and European corn borer
Common stalk borer affects younger corn than the European corn borer as peak damage typically occurs in June and July and can appear as wilt and deformities including twisting or stunting. In severe cases, the entire plant may bend over. If either the stalk borer or European corn borer enters the leaf whorl, leaves will unfurl with irregular holes where the borer has chewed.
Billbug damage
Billbugs feed belowground or within the crown of the plant. Most damage to corn plants occurs in May. Billbugs leave telltale feeding slits on lower stems, creating wilted leaves in the center of the leaf whorl. Billbugs can cut off leaves and entire young seedlings. Larger plants may be twisted, and as leaf blades unfurl, you will notice a line of holes (often a series of three to four) across the leaf.
Southern corn leaf beetle damage
Southern corn leaf beetle larvae are typically most damaging to corn from May to July. Larvae eat into the side of the plant about 1" above the soil surface, causing the plant to bend over, hindering leaves from unfurling and growing. Adult beetles feed on corn seedling stems and leaves. These beetles create distinct notched holes in the leaves as they chew on the edges of leaves and stems.
Wireworm damage
Wireworm damage is exacerbated by cool, wet, early-spring weather and typically peaks late May to June. They can destroy seeds before germination. Wireworms also feed on the underground portion of the stem and roots, leading to death of seedlings or wilting, poor stand establishment and stunted growth. Stunted plants typically appear dark or purplish.
Can corn recover from cutworm damage?
Partially cut seedlings may recover without major yield consequences if they’re cut above the growing point. Many times young corn plants are completely cut and will die.
The chances of a crop recovering from cutworm damage are impacted by:
- The level of the cut (the higher the better)
- The timing of the cut (if cutting occurs earlier in seedling development, the seedling has higher regrowth potential)
- Planting density (higher planting densities can help mitigate damage as nearby plants compensate for lost or stunted plants)
How do you get rid of cutworms?
Two defensive strategies for managing cutworm include selecting corn seed with Bt traits or using a seed treatment for cutworm.
For existing cutworm infestations, post-emergence rescue insecticide treatments such as Fastac® CS are effective if the application can be made quickly while cutworms are still actively feeding.
Experts are available to help you protect your corn from the roots to the tassel. Reach out to your seed retailer, a nearby extension office agent or your regional BASF representative.
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Endnotes
- Flandermeyer, Laura, and Emily N. Bick. “Managing Black Cutworm in Wisconsin Corn Fields.” Crops and Soils, University of Wisconsin-Madison, 11 July 2025, cropsandsoils.extension.wisc.edu/articles/managing-black-cutworm-in-wisconsin-corn-fields/. Accessed 25 May 2026.
