. |
|
| Pest |
Preplant |
Emergence to 4 leaf stage |
5 leaf stage to silking |
| White Grubs |
1 per sq. ft. - sandy soils
2 per sq. ft. - clay soils |
|
|
| Wireworms |
1 per sq. ft. - sandy soils
2 per sq. ft. - clay soils |
|
|
| Slugs |
3 per sq. ft. |
3-5 per plant |
|
| Cutworms |
|
1-2 leaf - 3% cut or 10% feeding damage
2-4 leaf - 5% cut and larvae present |
|
| Corn flea beetle |
|
5-6 per plant and 50% plants damaged |
|
| Common stalk borer |
|
2 leaf - 4% infested plants
3 leaf - 6% infested plants
4 leaf - 10% infested plants |
|
| European corn borer |
|
50% plants infested (irrigated)
80% plants infested (non-irrigated) |
50% plants infested (irrigated)
80% plants infested (non-irrigated) |
| True armyworm |
|
25% plants infested and larvae < 1" |
25% plants infested and larvae < 1" |
| Cereal leaf beetle |
|
|
10 per plant and 50% plants damaged |
| Fall armyworm |
|
|
75% plants infested with 1 worm or 50% plants with 2 or more worms |
| Northern corn rootworm * |
|
|
2 adult beetles per plant |
| Western corn rootworm * |
|
|
1 adult beetle per plant |
