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Extension > Garden > Diagnose a problem > What's wrong with my plant? > Vegetable > Sweet corn > Chewing damage on kernels

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Sweet corn > Ear > Chewing damage on kernels

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  • Image: Nitrogen Deficiency 1
  • Image: Aphid 2
  • Image: Aphid 3

Corn Earworm
Helicoverpa zea

  • Larvae feed on the kernels, especially at the tip of the ears
  • Corn is vulnerable to CEW larval feeding from row-tassel to 100% silk
  • Fully grown larvae are about 2 inches long and develop a wide range of colors from pale green to pink to almost black
  • More information on Corn Earworm...
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  • Image: Nitrogen Deficiency 1
  • Image: Aphid 2
  • Image: Aphid 3

European Corn Borer

  • Kernels partly or completely chewed; brown droppings (excrement) is usually present
  • Stalks can fall over ("lodge")
  • Small holes should be evident on stalks, sometimes with brown frass coming out of the holes
  • Leaves have small holes, or "shot-holes"
  • Larvae are light brown or pinkish gray in color with round dark spots on each body segment. Mature larvae are about 1 inch long
  • More information on European Corn Borer...
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  • Image: Nitrogen Deficiency 1
  • Image: Aphid 2
  • Image: Aphid 3

Sap Beetles
Carpophilus lugubris and Glischrochilus quadrisignatus

  • Individual kernels are chewed, and some kernels appear hollowed out
  • Adult beetles are small (1/8 - 1/4 inch long), oval, and black or brownish, sometimes colored with orange or yellow
  • Small yellowish or pinkish-white grubs may be found in ear tips along with adults
  • Can be found from silk to ear maturity
  • More information on Sap Beetles...

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