Alfalfa seed-Cutworm

Most common species:

Army cutworm (Euxoa auxiliaries)
Clover cutworm (Scotogramma 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.
  • chlorantraniliprole (Coragen) at 0.045 to 0.065 lb ai/acre. 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.
  • chlorantraniliprole/lambda-cyhalothrin (Voliam Xpress) at 5 to 8 fl oz/a. PHI 1 day for forage and 7 days for hay. REI 24 hr. Minimum of 5 days between applications. Do not exceed a total of 31.0 fl oz of Voliam Xpress or 0.12 lb ai of lambda-cyhalothrin or 0.2 lb ai of chlorantraniliprole per acre per growing season.
  • 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 (Warrior) at 0.015 to 0.025 lb ai/a. PHI 1 day for forage, 7 days for hay. REI 24 hr. Do not exceed 0.03 lb ai/a per cutting or 0.12 lb ai/a per season. Do not apply on ground within 25 ft of aquatic habitat, 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.
  • 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, 14 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.
  • zeta-cypermethrin (Mustang) at 0.028 to 0.05 lb ai/a. PHI 3 days for cutting or grazing, 7 days for harvest. REI 12 hr. Allow at least 7 days between treatments. Do not exceed 0.05 lb ai/a per cutting or 0.15 lb ai/a per season. Do not apply on ground within 25 ft of aquatic habitat, 150 ft if applied by air, or 450 ft if applied from ULV.