Corn: Corn Earworm (CEW) (Helicoverpa zea)


Pub 812: Field Crop Protection Guide > Chapter 1: Corn > Corn Earworm (CEW)

Field Crop Protection Guide 2011-2012, Order 2011-2012 publication

Table of Contents

  1. Description
  2. Integrated Pest Management Options
  • cyhalothrin-lambda - Matador 120 E, Silencer 120 EC
  • cypermethrin - Ripcord 400 EC
  • chlorantraniliprole - Coragen
  1. 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.

For best results, apply at or shortly after egg hatch. Target insecticides to cover the corn ear and silks.

 
Active ingredient cyhalothrin-lambda
Trade name Matador 120 E
Rate per hectare (product) 83-187 mL per ha
Rate per acre (product) 34-76 mL per ac
PHI* 14(silage) 21 (field and seed)
Comments Ground and aerial application. For best results, apply in the early morning, before temperatures rise, or during the evening. Use 100-200 L water/ha for ground application, 10-40 L water/ha for aerial application. Spray no later than 10 days after egg hatch. Maximum 3 applications/yr. Do not apply more than 2 applications of 83 mL/ha by air. 24-hr re-entry period.

 

 
Active ingredient cyhalothrin-lambda
Trade name Silencer 120 EC
Rate per hectare (product) 83 mL per ha
Rate per acre (product) 34 mL per ac
PHI* 14(silage) 21 (field and seed)
Comments Ground and aerial application. For best results, apply in the early morning, before temperatures rise, or during the evening. Use 100-200 L water/ha for ground application, 10-40 L water/ha for aerial application. Spray no later than 10 days after egg hatch. Maximum 3 applications/yr. Do not apply more than 2 applications of 83 mL/ha by air. 24-hr re-entry period.

 

 
Active ingredient cypermethrin
Trade name Ripcord 400 EC
Rate per hectare (product) 175 mL per ha
Rate per acre (product) 70 mL per ac
PHI* 5
Comments Ground and 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. Maximum 3 applications/yr. Do not apply more than 2 applications by air. Re-entry period when foliage dries.

 

 
Active ingredient chlorantraniliprole
Trade name Coragen
Rate per hectare (product) 250-375 mL per ha
Rate per acre (product) 101-151 mL per ac
PHI* 14 (field corn) 1 (seed corn)
Comments Apply to foliage when rain is not expected in the next 24 hr. Use a minimum of 100 L/ha of water. Maximum 4 applications/yr. 12-hr re-entry period.

 


Related links...


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 2 May 2011
Last Reviewed: 10 May 2011