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