Most common species:
Army cutworm (Euxoa auxiliaries)
Clover cutworm (Anarta trifolii)
Redbacked cutworm (Euxoa ochrogaster)
Variegated cutworm (Peridroma saucia)
Pest description and crop damage Cutworm larvae color ranges from dull gray, black, or brown to green; they may be striped or spotted. They often curl up when disturbed. Cutworms usually feed at night. They cut off young plants or feed on the foliage of older plants. If alfalfa fields do not "green up" in the spring, they may have cutworms (particularly redbacked or army cutworms). By day, larvae are in the soil usually at the moisture line or under surface litter. Some growers say that irrigating fields before treating gives better control.
Management-chemical control
- Bacillus thuringiensis kurstaki (Deliver) at 0.25 to 1.5 lb product/A. PHI 0 days. REI 4 hr. Most effective on small caterpillars; use highest recommended rate for fully developed ones. A spreader-sticker may improve performance.
- chlorpyrifos (Chlorpyrifos 4E-AG) at 0.5 to 1 lb ai/A. REI 24 hr. Application rates will vary depending on the nozzle droplet type. Toxic to fish, aquatic invertebrates, small mammals and birds. Highly toxic to bees. Buffer zones must be utilized for aquatic areas when using ground boom (25 ft), chemigation (25 ft), orchard airblast (50 ft), and aerial (150 ft). Do not cut or graze alfalfa within 7 days after application of 0.5 pint/acre, 14 days after application of 1 pint, and 21 days after application of > 1 pint/acre. Labeled for Idaho.
- chlorantraniliprole (Coragen) at 0.045 to 0.065 lb ai/A. REI 4 hr. PHI 0 days. Make no more than 4 applications per acre per crop. Do not make more than one application per cutting. Do not apply more than 15.4 fl oz Coragen or 0.2 lb ai of chlorantraniliprole per acre per crop.
- gamma-cyhalothrin (Proaxis, Declare) at 0.0075 to 0.0125 lb ai/A. PHI 1 day for forage, 7 days for hay. REI 24 hr. Do not exceed 0.06 lb ai/A per season or 0.015 lb ai/A per cutting. Do not apply on ground within 25 ft of aquatic habitat, 150 ft if applied by air, or 450 ft if applied from ULV.
- lambda-cyhalothrin (Serpent 1EC, Warrior II) at 0.015 to 0.025 lb ai/A. PHI 1 day for forage, 7 days for hay. REI 24 hr. Do not apply more than 0.03 lb ai (3.84 fl oz or 0.24 pint of product) per acre per cutting, or more than 0.12 lb ai (15.36 fl oz or 0.96 pint of product) per acre per season. Do not apply on ground within 25 ft of aquatic habitat (groundboom, overhead chemigation, or airblast), 150 ft if applied by air, or 450 ft if applied from ULV. Do not apply while bees are active. Advisable to move bee shelters for 2 to 3 days after application. Avoid application when bees are actively foraging by applying during the early morning or during the evening hours.
- lambda-cyhalothrin + chlorantraniliprole (Besiege) at 0.03 to 0.05 lb ai/A. PHI 1 day for forage and 7 days for hay. Do not exceed a total of 31.0 fl oz per year. Do not apply more than 10.0 fl oz per acre per cutting and no more than 1 application per cutting. Avoid application when bees are actively foraging by applying during the early morning or during the evening hours. It may be advisable to remove bee shelters during and for 2 to 3 days following application. Avoid direct application to bee shelters.permethrin at 0.05 to 0.2 lb ai/A. PHI 0 days at rates equal to or less than 0.1 lb ai/A, 30 days at rates greater than 0.1 lb ai/A. REI 12 hr. Do not reapply at less than 7-day intervals or exceed 0.2 lb ai/A per cutting. If used during bloom, remove bees from field for 3 days. Do not apply on ground within 25 ft of aquatic habitat, 100 ft if applied by air, or 450 ft if applied from ULV.
- zeta-cypermethrin (Mustang Max) at 0.014 to 0.025 lb ai/A. PHI 3 days for cutting or grazing, 7 days for harvest. REI 12 hr. Allow at least 7 days between applications. Do not exceed 0.05 lb ai/A per cutting or 0.15 lb ai/A per year. Do not apply on ground within 25 ft of aquatic habitat, 150 ft if applied by air, or 450 ft if applied from ULV.