Description of the Pest
Several species of grasshoppers may attack sugarbeets. Both adults and nymphs can cause damage. Injury is more likely near the foothill rangeland; however, grasshoppers can migrate great distances.
Damage
Grasshoppers consume foliage, and if infestations are severe, may defoliate entire fields.
Management
A large contingent of natural enemies serve to hold grasshopper populations in check most years. However, in outbreak years and particularly after an invasion, other intervention will likely be needed. Because most grasshopper problems begin outside of the field, migrating invaders should be monitored closely. Apply treatment if and when a field is invaded.
| 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. | CARBARYL | |||
| (Sevin 5 Bait) | 30 lb | 12 | 28 roots/forage | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Repeat applications as necessary up to a total of 2 times per year but not more often than 14 days apart. | ||||
| ‡ | 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 two intervals is the minimum time that must elapse before harvest. |
| 1 | Group numbers for insecticides and miticides are assigned by IRAC (Insecticide Resistance Action Committee). 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. |