Key Points

  • Common stalk borer is a sporadic and infrequent pest of corn in much of North America.
  • Damage to corn is most common near field borders, waterways, or terraces, and in continuous corn.
  • Several available Bt corn technologies provide control or suppression of common stalk borer larvae.

Pest Facts and Impact on Crop

  • Latin name: Papaipema nebris.
  • Native to North America; may be found in most areas east of the Rockies.
  • Sporadic and infrequent pest of corn; incidence increases with no-till or grass weed infestation.
  • Highest incidence usually occurs in rows closest to grass field borders, waterways, or terraces with large weeds (e.g., giant ragweed), or in continuous corn.
  • Development begins in grasses, but larvae move at about 1400 - 1700 GDU (base 41 °F) to larger hosts, including nearby corn.
  • Primary hosts are corn, quackgrass, giant ragweed, wirestem muhly, tomato, and occasionally soybeans.
  • Has no known significant natural enemies.

Photo - closeup stalk borer larva on leaf

Stalk borer

Injury Symptoms

  • Stalk borers tunnel into corn stalks above the soil or climb directly into the whorl resulting in tattered leaves.
  • Young plants (VE-V3) may be killed by tunneling below the growing point.
  • On older plants (V4-V8), the leaves will usually discolor, wilt, and die if tunneling is between them and the growing point; often called “dead heart.”
  • Plants infested after the V8 stage usually show little visible injury.
  • Non-lethal infestations in early-stage plants cause stunting, tillering, delayed development, and increase frequency of barren plants, reducing yield.

Photo - growing corn plant damaged from common stalk borer

Dead "heart"

Photo - stunted ears on corn plant - insect damage

Stunted ears

Photos - Side by side - stalk borer tunneling into plant stalk and damaged corn plant

Tunnel in corn stalk.

Pest ID - Key Characteristics

  • Stalk borer larvae are cream to light brown with a dark purple saddle on the forward half of the body.
  • Larvae have dark streaks on either side of their heads.
  • As larvae grow, the purple becomes dilute and faded.
  • Larvae are about ½ inch long when they leave grass and will reach nearly 2 inches at full development before fall.

Photo - Early-stage stalk borer head - closeup

Early-stage stalk borer head

Photo - early-stage stalk borer on leaf - closeup

Early-stage stalk borer.

Photo - late-stage stalk borer on leaf - closeup

Late-stage stalk borer.

Areas Prone to Common Stalk Borer Injury

Photo - insect egg laying site - grass terrace corn field

Egg laying site: grass terrace.

Photo - stunted corn plants in border rows infested with stalk borers.

Stunted corn in border rows infested with stalk borers.

Photo - insect egg laying site - giant ragweed and grasses

Egg laying site: giant ragweed and grasses.

Management Considerations

  • Tillage or herbicide grass control in the prior fall will reduce ovipositional attractiveness.
  • Burning grassy field borders before planting may destroy eggs.
  • Begin scouting at about 1300 GDU (41° base) accumulation since January 1.
    • Grassy or weedy field edges, such as shelterbelts, terraces, waterways.
    • No-till fields with heavy vegetation prior to burn down.
  • Resistance available
    • Several available Bt corn technologies provide control or suppression of common stalk borer larvae.
  • Pesticide use and timing
    • Most effective if timed when larva are leaving host plants after a herbicide application.
    • Maximum 80% effective when used on infested plants, spray only infested areas of the field.
    • On corn plants below V6, less than 10% infestation may warrant spot treatment, later than V7 nearly 100% of the plants must be infested to warrant treatment

Pest ID - Related/Confused Species

Several species share the same habitat and may cause similar looking injury.

Other borers:

Photo - Eurpean corn borer - no purple

Eurpean corn borer - no purple


Photo - Corn earworm - multicolored stripes

Corn earworm – multicolored stripes


Photo - Hop vine borer - no stripe on side of head - burrows up from root

Hop vine borer – no stripe on side of head, burrows up from root


Photo - Fall armyworm - multicolored stripes

Fall armyworm – multicolored stripes


Photo - Southwestern corn borer - dark spots - no stripe on side of head

Southwestern corn borer – dark spots, no stripe on side of head


Photo - Lesser cornstalk borer - purple bands - not striped

Lesser cornstalk borer – purple bands - not striped


Other seeding feeders:

  • Billbug, wireworm, cutworm

Stalk Borer Annual Cycle

Timeline - common stalk borer life cycle.

Click here or on the image above for a larger view.


Photo - man on phone walking in cornfield - midseason - cloudy sky

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The foregoing is provided for informational use only. Please contact your Pioneer sales professional for information and suggestions specific to your operation. Product performance is variable and depends on many factors such as moisture and heat stress, soil type, management practices and environmental stress as well as disease and pest pressures. Individual results may vary. Pioneer® brand products are provided subject to the terms and conditions of purchase which are part of the labeling and purchase documents.