Sweet corn sweet corn sweet corn..INSECT CONTROL

Consumer demand for damage-free sweet corn means that growers must develop the an economical and effective management program for insect pests, especially those that attack the ear. Additional insecticide information is available from ID-36, "Commercial Vegetable Crop Recommendations."

Cutworms (Agrotis spp.)

While they are potentially very destructive, cutworms are unpredictable, and the chances of significant damage in any given year are relatively low. Sweet corn can be seriously damaged by cutworms from planting through mid-June while the plants are less than 18 inches tall. Serious losses are often associated with wet springs that have caused a delay in planting.
Cutworms are the larvae of moths. These night-flying moths are frequently attracted to lights at night. The 1-1/2 to 2-inch moths are dull-gray to brown with yellow, gray, light brown, and black designs on the front wings. The hind wings are usually solid in color and lighter than the front wings. Moths lay eggs singly or in clusters on the leaves of grasses, weeds, other host plants, and sometimes on the bare ground. Cutworms are smooth-skinned and somewhat shiny. They range in color from gray to dark brown with distinctive stripes and spots. When fully grown, cutworms can reach 1-3/4 inches in length. Cutworms commonly coil up in a "c" shape when disturbed.
Cutworms feed mostly at night and hide during the day under clods of soil or in burrows below the soil surface. They cut off the stalks of young plants at or just below the soil surface and feed on the buds or leaves. They rarely consume the entire plant, but more commonly move to the next plant in the row or to another row. Infestations typically are not uniform within a field, so the loss of a plant stand tends to occur only in parts of a field.
Controls
Biological: Cutworms are parasitized by tachinids, Archytas, Bonnetia, Eucelatoria and Winthemia spp., by braconids, Apanteles, Chelonus, Meteorus, and Microplus spp., and by inchneumonids, Campoletis, Hyposter, Nepiera and Pterocornus spp. They are also readily fed on by many species of birds.
Cultural: Eliminate weeds from field margins and prepare fields at least two weeks prior to planting to destroy cutworm food sources and egg laying sites. Monitoring: Early detection of economic infestations means that an insecticide can be applied before serious damage occurs. Careful scouting of corn fields is the most effective means of detecting economic infestations of
cutworms. Scouting for cutworms should begin as soon as the corn emerges and continue twice weekly until the plants reach 18 inches high.
In at least five areas of the field, examine 20 consecutive plants. Note the number of plants that are cut, wilted, or showing signs of leaf feeding. While walking through the field, observe the evenness of cutworm infestations.Look for live cutworms around freshly damaged plants. First, check under clods around the base of plants. Then, dig up an area three inches in radius and three inches deep around the plant. Under dry conditions, cutworms are found lower in the soil.
When 3% or more of the plants are cut and two or more small cutworms (1" or smaller) per 100 plants are observed, then control action may be warranted. Exceptionally high or low stand counts can be used to adjust the 3% value. If conditions are borderline, scout the field again in 24 to 48 hours or until a final decision is made.

Application Alternatives :

Ambush 2 E (permethrin)- Apply as a foliar treatment at 6.4 to 12.8 fl oz per acre to a limit of 76.7 fl oz per acre per season.
Baythroid 2 (cyfluthrin)- Apply as a foliar treatment at 0.8 to 1.6 fl oz per acre to a limit of 10 applications per season.
Force 3 G (tefluthrin) soil applied T-band or infurrow at 4 to 5 ounces per 1000 row feet.
Lorsban 4 E (chlorpyrifos)- Incorporate preplant at 2 to 4 pt per acre or apply as a foliar treatment at a rate of 2 to 3 pt per acre.
Lorsban 15 G (chlorpyrifos)- Incorporate preplant at 6.75 to 13.7 lb per acre or use a banded or T-band application at a rate of 8 oz per 1000 row feet.
Pounce 3.2 EC (permethrin)- Apply as a foliar treatment at 4 to 8 fl oz per acre to a limit of 48 oz per acre per season.
Warrior 1 EC (lambda-cyhalothrin)- Apply as a foliar treatment at 2.56 to 3.84 fl oz per acre to a limit of 3.84 pt per acre per season.