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Corn: Corn Earworm (CEW) (Helicoverpa zea)

Author: OMAFRA Staff
Creation Date: 04 July 2005
Last Reviewed: 15 June 2009
Pub 812: Field Crop Protection Guide > Chapter 1: Corn > Corn Earworm (CEW)

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

Table of Contents

  1. Description
  2. Integrated Pest Management Options
  3. Related links...

Description

Corn earworm larvae vary greatly in colour from light green to yellow. The full-grown larvae are 4 cm
(1 1/2 in.) long with prominent stripes running the length of their bodies.

Image 1. Corn earworm larva on corn ear. Larval feeding is usually concentrated at the tip of the ear.
Image 1. Corn earworm larva on corn ear. Larval feeding is usually concentrated at the tip of the ear.

 

Integrated Pest Management Options

Insecticides have generally not provided economic control of CEW in field corn. There may be some value in treating seed corn to maintain kernel quality.

cyhalothrin-lambda – Matador 120 E, Silencer 120 EC
Active ingredient cyhalothrin-lambda cyhalothrin-lambda
Trade nameMatador 120 ESilencer 120 E
Rate per hectare (product)83-187 mL per ha83 mL per ha
Rate per acre (product)34-76 mL per ac34 mL per ac

Comments
Spray no later than 1st apperance of feeding. Spray no later than 14 days before silage harvest. No more than 3 applications per season, 2 may be by air.

cypermethrin – Ripcord 400 EC
Active ingredientcypermethrin
Trade nameRipcord 400 EC
Rate per hectare (product)175 mL per ha
Rate per acre (product)70 mL per ac

Comments
Ground or aerial application. Ensure good coverage of ears and silks. Use minimum 300-500 L/ha of water for ground application and 11-22 L/ha for aerial application. 5 days to harvest. Maximum of 3 applications per year, 2 may be by air.

Related links...

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