Description of the Pest
Larvae of the seedcorn maggot are small, pale or dirty-colored, yellowish white, legless maggots with tough skin. Adults are grayish brown flies and about 0.20 inch long.
Damage
Seedcorn maggots feed on the seed and may destroy it. Injury is most severe during wet, cold periods.
Management
In California, seedcorn maggots are only occasional pests. They are usually associated with high levels of organic matter in fields that have recently had a cover crop disked in.
| 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. | PHORATE* | |||
| (Thimet 20G) –at planting | 3.4–4.5 oz/1000 row ft | 72 | 30 | |
| (Thimet 20G) – postemergence | 4.9–7.5 lb | 72 | 30 | |
| MODE-OF-ACTION GROUP NUMBER1: 1B | ||||
| COMMENTS: Apply at planting; do not place granules in direct contact with seed. Do not feed tops to livestock. | ||||
| ‡ | 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. |
| * | Permit required from county agricultural commissioner for purchase or use. |
| 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. |