Corn: European Corn Borer (ECB) (Ostrinia nubilalis)

Excerpt from Chapter 1, Field Crop Protection Guide, Order this publication

Table of Contents

1. Description
2. Integrated Pest Management Options
   • Transgenic Bt Corn Hybrids
   • Seed Corn Only
• deltamethrin – Decis 5.0 EC
• cypermethrin – Ripcord 400 EC
• cyhalothrin-lambda – Matador 120 E, Silencer 120 EC
• Bacillus thuringiensis – Dipel 2X DF
• carbaryl – Seven XLR Plus
3. Related links...

Description

Egg masses are flat, creamy white and layered over each other, making the egg mass appear similar to fish scales. Mature larvae are creamy white to pale grey with 2 small spots per abdominal segment, approximately 2.5 cm in length and have a black head. Adults are light-brown moths approximately 2 cm long with dark wavy lines running across each forewing. Male moths are darker and smaller than females.

Image 1. European corn borer eggmass. Each eggmass can have 15-40 eggs, which are layered like fish scales.

Image 2. European corn borer larvae are cream to pink with black heads and two black spots per abdominal segment. Stalk rots can be carried in by the larvae.

Image 3. Adult European corn borer moths. Female (left) is larger and lighter in colour than the male (right).

Integrated Pest Management Options

To manage potential corn borer resistance, plant a minimum of 20% of total acreage to non-Bt corn refuge and position it so that the refuge is no more than 400 m from the Bt corn planting. Do not apply ECB insecticide to non-Bt refuge. For more information regarding Bt corn and/or refuge options, see A Grower's Handbook; Controlling Corn Insect Pests With Bt Corn Technology found on the Canadian Corn Pest Coalition website.

See OMAFRA Publication 811, Agronomy Guide For Field Crops, to calculate economic thresholds.

Transgenic Bt Corn Hybrids
Agrisure CB, Herculex I, Herculex Xtra, KnockOut, natureGard, YieldGard, YieldGard Plus, YieldGard VT, Triple

See table 9 - 4, Transgenic Crops Expressing Insecticidal or Fungicidal Traits, on page 84, for Bt Corn options.

Comments
Insecticides have generally not provided economic control of ECB in field corn. Using Bt transgenic corn provides much better control. Use corn hybrids that express the Bt toxin in the ear as well as the stalk to avoid stalk and ear rot. Keep careful and accurate records as to where Bt and non-Bt hybrids are planted.

Seed Corn Only

Comments
Ground or aerial application. Apply when egg masses begin to hatch but no later than when 1st pinhole feeding occurs on foliage. For 2nd brood in late planting, apply before tassels show. Repeat in 5-8-day intervals. Maximum 3 applications/yr. Do not feed silage or stubble to dairy cattle.

Comments
Apply when egg masses begin to hatch but no later than when 1st feeding occurs on foliage. For 2nd brood in late planting, apply before tassels show. Use a minimum 300-500 L water/ha for ground application and 11-22 L/ha for aerial application. Re-entry period when foliage dries. Maximum 3 applications/yr. Up to 2 applications/season by air. 5 days to harvest.

Comments
Ground or aerial application. Spray no later than 1st apperance of feeding. Spray no later than 14 days before silage harvest. Maximum 3 applications per season, 2 may be by air.

Comments
Good option for organically grown corn. Apply when pinhole feeding is observed in at least 5% of the plants. Repeat at 7-day intervals. Only effective against small larvae and must be applied before larvae begin stalk boring.

Comments
For larvae in whorls and foliage, treat entire plant. Repeat as necessary. For silks and ears, apply in 2-4-day intervals when silks first apear. 1 day to harvest. Follow label precautions applying to honeybees.

Related links...

• Agronomy Guide for Field Crops - Publication 811
  • Corn: European Corn Borer
• Transgenic Crops Expressing Insecticidal or Fungicidal Traits
• Insect
• Corn
• Canadian Corn Pest Coalition