Alfalfa seed-Webworm

Includes beet webworm (Loxostege sticticalis)

Pest description and crop damage Caterpillars vary from light to dark with three white longitudinal stripes and many black and white tubercles.

Management-chemical control

  • chlorantraniprole (Coragen) at 0.045 to 0.065 lb ai/acre. PHI 0 days. REI 4 hr. 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.
  • indoxacarb (Steward EC) at 0.065 to 0.11 lb ai/a. REI 12 hr. PHI 7 days. Make no more than one application per season. Do not apply when bees are in the area. Chemigation applications through center pivot is permitted.
  • 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.