Description of the Pest
Cutworm larvae feed at night They come in various colors and patterns but always appear as smooth-skinned caterpillars to the naked eye. They frequently roll into a C-shape when disturbed. The mature variegated cutworm larva is yellow to brown, a little over an inch long (3 cm), with a row of 4 to 6 yellow or pink, diamond-shaped spots down the back. The mature dark-sided cutworm is somewhat larger than the variegated cutworm (1.5–2 inches, 4–5 cm) and gray to greenish gray in color with irregular, longitudinal stripes.
Adult cutworm moths are rather nondescript, with dark gray or brown front wings that have irregular spots or bands and lighter hind wings.
Damage
Larvae feed at night on the tender tips of new asparagus spears, where they eat small holes. One-sided feeding may also cause the spears to curl. The variegated cutworm also feeds underground and at the soil surface. Fern damage is generally rare.
Management
Carry out good weed control in and around the field, and incorporate field trash and previous crop residues thoroughly to reduce egg and worm overwintering. Look for damage symptoms and confirm cutworm presence by digging into the soil an inch or so around a damaged spear.
Organically Acceptable Methods
Good weed management and field cultivation are acceptable to use in an organically certified crop.
| 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 Bait 5%) | Spears: 20 lb
Ferns: 40 lb |
12 | 1 | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Apply when pests appear in damaging numbers, and repeat 7–14 days later if necessary. Ground application. | ||||
| B. | METHOMYL* | |||
| (Lannate LV) | 1.5–3 pt | 48 | 1 | |
| MODE-OF-ACTION GROUP NUMBER1: 1A | ||||
| COMMENTS: Use low rate for variegated cutworm. Apply at 5- to 7-day intervals as needed. Do not apply more than 4.5 lb a.i./acre/crop. | ||||
| C. | 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). |