Description of the Pest
Asparagus beetle larvae are dark, green-gray grubs about 1/3 inch (9 mm) long when fully grown. Adults are blue-black beetles with a red prothorax. Their elytra (wing covers) have yellow spots and red borders.
Spotted asparagus beetle larvae are orange and adults are reddish orange with six prominent black spots on each wing cover.
Damage
Asparagus beetles injure the plant by feeding on the tips of tender young shoots. After leaves come out, asparagus beetles and their larvae gnaw on the surface of the stems and devour the leaves. If injury to the fern is severe, the crown is weakened, particularly if the asparagus stand is young.
Management
Although they are found wherever asparagus is grown, asparagus beetles are not normally serious pests in California. Some local infestations do occur, however, and control measures may be necessary to prevent serious injury to the asparagus stand, particularly when the stands are young. If beetles are feeding on spears early in the season, let some plants near the edge of the field produce fern growth to attract the beetles away from the spears. If necessary, treat these areas.
| 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. | SPINETORAM | |||
| (Radiant SC) | 4–8 fl oz | 4 | See comments | |
| MODE-OF-ACTION GROUP NUMBER1: 5 | ||||
| COMMENTS: Apply only postharvest to ferns; do not apply within 60 days of spear harvest. | ||||
| B. | METHOMYL* | |||
| (Lannate LV) | 1.5–3 pt | 48 | 1 | |
| (Lannate SP) | 0.5–1 lb | 48 | 1 | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Apply at 5–7 day intervals as needed. Do not apply more than 4.5 lb a.i./acre/crop. | ||||
| C. | CARBARYL* | |||
| (Sevin XLR Plus) | 1 qt | 12 | 1 | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Apply to ferns or brush growth. Repeat applications as necessary but not closer than 7 days and not more than 5 applications per year. If applying after harvest, use a rate of 2 quarts per acre. | ||||
| D. | PERMETHRIN | |||
| (Ambush, Pounce) | 3.2–6.4 oz | 12 | 1 | |
| MODE-OF-ACTION GROUP NUMBER1: 3 | ||||
| COMMENTS: Apply by ground equipment only. Do not apply more than 0.4 lb a.i./acre/season. | ||||
| ** | See label for dilution rates. |
| ‡ | 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 | Rotate insecticides 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. Mode-of-action group numbers are assigned by IRAC (Insecticide Resistance Action Committee). |