Corn Earworm / Borer (2026)

Corn, tomato, beans

Quick answer: Corn Earworm / Borer attacks corn, tomato, beans. Start with the organic/IPM steps below; use the chemical option only if damage escalates, and always follow the product label. Early planting; resistant varieties; destroy stalks in fall.

Your Corn Earworm / Borer IPM card

Select your state to see whether this pest is common there, then print.

Your state

Corn Earworm / Borer in Iowa: Listed among the most-reported pests in your state — watch for it.

Corn Earworm / Borer

Targets

Corn, tomato, beans

Signs

Holes in ears or stems; frass at entry.

Organic / IPM first

Bt (kurstaki) sprays; mineral oil on silk; crop rotation.

Chemical option (follow label)

Spinosad or pyrethroid at tassel stage.

Prevention

Early planting; resistant varieties; destroy stalks in fall.

More pests

Aphids Japanese Beetle Tomato Hornworm Squash Bug Squash Vine Borer Cutworm Cabbage Maggot Whitefly

Treatments follow integrated pest management (IPM): identify first, least-toxic fix second. Product specifics and labels vary by state — confirm with your county extension.