Sunflower XIV-1

Darksided Cutworm

Frank B. Peairs


Cutworm Adult	Cutworm Larva

Field Biology and Identification

This cutworm has a grayish-brown abdomen with a narrow dark gray stripe on either side just above the spiracles. The mature larvae are about 30 to 35 millimeters in length and five millimeters wide. It is an early season pest that has but one generation per year. The grayish-brown colored adult moths are found in late summer and autumn. The female moths deposit eggs in the soil in late July and early August. These eggs remain dormant until the air temperatures warm during the following spring. The larvae feed and grow until about the end of June and then pupate in earthen cells near the soil surface.

Plant Response and Damage

Young darksided cutworms may climb up plants to feed on foliage, leaving the plant leaves with a chewed appearance. Younger larvae may chew small, transparent "windows" in young leaves. Older cutworms may cut plants off from one inch below the soil surface to two inches above the soil surface. Most cutworm feeding occurs at night and remain just under the soil surface during the day. Wilted, broken, or dead plants may indicate the presence of cutworms.

Management Approaches

Chemical Control

Check fields early and control if there is one cutworm per square foot or if stands are reaching the lower limit for optimum plant populations. Treatment may not be necessary if most larvae are fully grown (1 ? to 1 ? inches) and therefore close to the end of their feeding period.

Product list for Darksided Cutworm:
Pesticide	Product/Acre (Fl oz. or oz. product)	Preharvest Interval, remarks
Asana XL^R^,1	5.8 - 9.6	28 days. Do not feed forage or fodder tolivestock. Extremely Hazardous to Bees!
Baythroid XL^R^,1	0.8 - 1.6	30 days. Extremely Hazardous to Bees!
carbaryl¹^,2	See labels	60 days. 30 days to graze or forage. Extremely Hazardous to Bees!
chlorpyrifos 4E^R1,2	32 - 48	42 days. Do not graze. Up to 2 lb preplant. Up to 4.5 lb total AI/yr. Extremely Hazardous to Bees!
Delta Gold^R^,1	1.0 ? 1.5	21 days to harvest. Do not apply more than 0.045 lb ai/acre/crop.? Do not graze or feed treated forage to livestock. Extremely Hazardous to Bees!
lambda cyhalothrin^R1,2	1.92 ? 3.20	45 days. Do not exceed 0.12 lb total AI/yr. Extremely Hazardous to Bees!
Proaxis^R^,1	1.92 ? 3.20	45 days. Do not exceed 0.06 lb total AI/yr. Extremely Hazardous to Bees!
^RRestricted use pesticide. ¹Labeled for chemigation. ²Generic active ingredient, may be additional formulations.
The information herein is supplied with the understanding that no discrimination is intended and that listing of commercial products, necessary to this guide, implies no endorsement by the authors or the Extension Services of Nebraska, Colorado, Wyoming or Montana. Criticism of products or equipment not listed is neither implied nor intended. Due to constantly changing labels, laws and regulations, the Extension Services can assume no liability for the suggested use of chemicals contained herein. Pesticides must be applied legally complying with all label directions and precautions on the pesticide container and any supplemental labeling and rules of state and federal pesticide regulatory agencies. State rules and regulations and special pesticide use allowances may vary from state to state: contact your State Department of Agriculture for the rules, regulations and allowances applicable in your state and locality.

Categories: Sunflower, Insects, Darksided cutworm

Date: 5/17/2007