Description of the Pest
Grasshoppers can be occasional early season pests. In late summer and fall, grasshopper eggs are laid in grassy foothills, on ditchbanks, along roadsides and fence rows, in pasture areas, and in alfalfa fields. The eggs hatch in spring and the young nymphs feed on nearby plants. When wild grasses and other plants become dry, the grasshoppers migrate to irrigated croplands.
Damage
Grasshoppers feed on foliage, most often on the edges of fields near pasture areas or roadsides. They seldom cause economically significant injury.
Management
Topical treatments are most effective; treating field borders may be adequate. Insecticidal baits are not effective in cotton itself but may be when applied to rangelands or other breeding grounds before grasshoppers migrate to crops.
| Common name | Amount per acre** | REI‡ | PHI‡ | |
|---|---|---|---|---|
| (Example trade name) | (hours) | (days) | ||
| Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Always read the label of the product being used. | ||||
| A. | MALATHION | |||
| (Malathion 8-E) | 1.5–2 pt | 12 | 0 | |
| SELECTIVITY: Low | ||||
| PERSISTENCE: Pest: Short NE:2 Short | ||||
| MODE-OF-ACTION GROUP NUMBER 1: 1B | ||||
| COMMENTS: Limited residual effectiveness. | ||||
| B. | NALED | |||
| (Dibrom 8EC) | 0.5–0.75 pt | 48 | See comments | |
| SELECTIVITY: Low | ||||
| PERSISTENCE: Pest: Short NE:2 Short | ||||
| MODE-OF-ACTION GROUP NUMBER 1: 1B | ||||
| COMMENTS: Apply before bolls open. Do not graze livestock in treated fields. Destructive of natural biological control. Tank mixing may affect selectivity and persistence of this material. Do not apply more than 5 pt/acre/season. | ||||
| ** | Mix with sufficient water to provide complete coverage. |
| ‡ | Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases, the REI exceeds the PHI. The longer of the two intervals is the minimum time that must elapse before harvest. |
| 1 | Group numbers for insecticides and miticides are assigned by the Insecticide Resistance Action Committee (IRAC). Rotate pesticides with a different mode-of-action group number, and do not use products with the same mode-of-action group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a group number of 1B; insecticides with a 1B group number should be alternated with insecticides that have a group number other than 1B. |
| 2 | NE = natural enemies |