European Corn Borer

Symptoms of European Corn Borer

  • Larvae feed on all above-ground plant parts
  • Pre-tassel feeding:
    • Small larvae inside whorl and leaf midrib
    • Large larvae tunnel into stalk at base of plant
  • Tassel-stage and later feeding:
    • Small larvae in leaf collar and silks
    • Large larvae tunnel into stalks, ear, ear shank
  • Yield reductions:
    • Disrupted water/nutrient flow
    • Damaged kernels
    • Broken stalks and dropped ears
  • Quality reduction:
    • Broken kernels
    • Ear rot infection source
    • Ear rots develop mycotoxins
    • Lower value at elevator
    • Loss of grain in storage

Comparison IDs

Corn earworm larva

Corn Earworm

  • Large, many colors
  • Found in ear only


Sod webworm larva

Sod Webworm

  • Usually found in leaves
  • Accompanied by slight webbing


Southwestern corn borer larva

Southwestern Corn Borer

  • Southern areas of U.S. only
  • Dark spots on white background or pure white in late fall


Lesser corn stalk borer larva

Lesser Corn Stalk Borer

  • Purple bands
  • Found sporadically, rarely significant

Pest Facts and Impact on Crop

  • Latin name: Ostrinia nubilalis
  • Native to Europe and western Asia, ECB is found throughout the Corn Belt east of the Rocky Mountains – there is a similar species in Asia
  • One of the most important pests of corn in the United States
  • One larva per plant tunneling in stalk may reduce yield by up to:
    • 5-8% pre-tassel
    • 2-5% post-tassel
  • European corn borer is able to feed on most plants with fleshy parts or stems
    • Broadleaf and grassy weeds
    • Other crops: soybeans, peppers, tomatoes, strawberries, etc.

U.S. Map - generations of European Corn Borer per year.

Life Cycle of European Corn Borer

                            European Corn Borer Annual Cycle in Corn

Annual life cycle of the European Corn Borer.

Management of European Corn Borer

  • European corn borer be found in the field over the winter, but severity of the upcoming problem on new corn plantings is difficult to predict and depends greatly on in-season weather and pest interactions
  • The large number of predators, parasites and pathogens can also make a high population crash unexpectedly
  • Adults are mobile, and fields with egg laying cannot be predicted
  • Egg survival and synchronization to the crop is highly weather dependent
  • In areas of multiple generations, late-planted fields are more at risk than early planted fields
In-Season Monitoring
  • Peak moth flight activity is determined by pheromone and light trap catches and can be used to time a more detailed field scouting program for pesticide application
  • Scout fields during first and later generations
  • Decide if expected injury level warrants action
  • Apply an insecticide by air as needed
  • Because of the non-synchronous nature of the pest life cycle, use of insecticides rarely gives better than 80% control

Use of Transgenic Products and Technologies
  • Transgenic Bt corn gives unsurpassed corn borer control without scouting
    • Herculex® I, Herculex® XTRA, YieldGard® Corn Borer
    • Planting of a non-transgenic refuge is mandatory when using most current transgenic products
      • 20% in Corn Belt and northern states
      • 50% in southern states or counties where cotton is grown

HX1 – Contains the Herculex® I Insect Protection gene which provides protection against European corn borer, southwestern corn borer, black cutworm, fall armyworm, lesser corn stalk borer, southern corn stalk borer, and sugarcane borer; and suppresses corn earworm.
HXX – Herculex® XTRA contains both the Herculex I and Herculex RW genes.
Herculex® Insect Protection technology by Dow AgroSciences and Pioneer Hi-Bred. Herculex® and the HX logo are registered trademarks of Dow AgroSciences LLC.
YGCB – The YieldGard® Corn Borer gene offers a high level of resistance to European corn borer, southwestern corn borer and southern cornstalk borer; moderate resistance to corn earworm and common stalk borer; and above average resistance to fall armyworm.
YieldGard®, the YieldGard Corn Borer design and Roundup Ready® are registered trademarks used under license from Monsanto Company.