Cutworm Cutworm

Cutworm

    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.


Damage

    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.


Recommendations

    Late planting, moderate to heavy infestations of broadleaf weeds prior to planting, poor field drainage, or an abundance of crop residue, especially soybean straw, are factors that contribute to cutworm problems. Fields with combinations of these characteristics or a history of cutworm problems have an increased potential for damage. Preplant or planting time applications of soil insecticides or broadcast sprays may reduce cutworm damage but are generally not an economical strategy. Fields receiving a preventive cutworm treatment should be watched; economic damage may occur where cutworm pressure is great. Rescue treatments can be applied when field inspection indicates that an economic infestation is present. This is the most cost efficient strategy to follow. Frequent field scouting and early detection of the problem is essential. Treat when 3 % of the stand is cut and 2 or more larvae (1" or smaller) are found per 100 plants. Control may be unsatisfactory if the soil is dry and crusted and the cutworms are feeding well below the soil surface. Under hot, dry conditions, control with some products may be enhanced by cultivation or use of rotary hoe after application.

Cutworm Preventive Treatments
Insecticide Rate Notes
Ambush2 E 6.4 - 12.8 fl oz per acre Apply no more than 5 days prior to emergence.
Asana XL 5.8 to 9.6 fl oz per acre  
Aztec 2.1% G 6.7 oz per 1,000' of row Apply as a T-band
Aztec 4.67% G 3 oz per 1,000' of row Apply as a T-band
Baythroid 2 0.8 to 1.6 fl oz grain/fodder 21 days, green 0 day
Capture 2 EC 0.3 oz per 1,000' of row Apply as a T-band
Capture 1.15G 6.4 to 8 oz per 1,000' of row Apply as a T-band
Capture 1.15G 3.2 to 8 oz per 1,000' of row Apply in-furrow
Force 3% G 4 to 5 oz per 1,000' of row May use 3 to 4 oz with T-band or banded applications in 1st year corn only
Lorsban 15% G 8 oz per 1,000' of row Apply as a T-band or band
Lorsban 4 E 2 to 4 pints per acre Preplant incorporation
Lorsban 4 E 2.4 fl oz per 1,000' of row Apply as a T-band in front of press wheel
Pounce 1.5% G 8 oz per 1,000' of row Apply as a T-band or band
Pounce 3.2 EC 4 to 8 fl oz per acre Broadcast or banded sprays
Warrior T 1.92 to 3.20 fl oz per acre  

Cutworm Rescue Treatments
Insecticide Rate per Acre Notes
Ambush 2 E 6.4 - 12.8 fl oz per acre  
Asana XL 5.8 to 9.6 fl oz per acre 21 day PHI
Baythroid 2 0.8 to 1.6 fl oz grain/fodder 21 days, green 0 day
Capture 2 EC 2.1 to 6.4 fl oz 30 day PHI
Lorsban 4 E 1 to 2 pints 35 day fodder interval
Mustang 1.5 1.4 to 3.0 fl oz 30 day grain, 60 day silage PHI
Penncap-M 2FM 4 pints Ground only, 12 day PHI
Pounce 3.2 EC 4 to 8 fl oz 30 day PHI
Sevin 80 S 2-1/2 lbs 12" band
Warrior T 1.92 to 3.20 fl oz per acre 21 day harvest

For more information, see ENT-59