Alfalfa seed-Grasshopper

Includes several species, especially Melanoplus spp.

Pest description and crop damage Both nymphs and adult grasshoppers can cause plant damage. In addition to foliage injury, feeding on blossoms prevents seed formation.

Management-chemical control

  • diflubenzuron (Dimilin 2L) at 0.031 lb ai/a. PHI 0 days. REI 12 hr. For nymph control only. Do not feed, graze, or cut hay for forage. Not for human consumption. Do not apply at ground level within 25 ft of aquatic habitat, 150 ft if applied by air. SLN ID-000013; OR-0800032; WA-000024.
  • dimethoate 4EC at 0.25 to 0.5 lb ai/a. PHI 10 days. REI 48 hr. Do not feed any crop portion within 10 days of treatment. Do not apply during bloom.
  • gamma-cyhalothrin (Proaxis, Declare) at 0.01 to 0.015 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 0.02 to 0.03 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.
  • malathion 8EC at 0.75 to 1.25 lb ai/a. PHI 0 days. REI 12 hr. Not effective below 65ºF. Not recommended for fields pollinated with leafcutters.
  • Nosema locustae (Nolo Bait)-PHI 0 days. Use as directed.
  • zeta-cypermethrin (Mustang) at 0.035 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.