Sitona hispidula
Pest description and crop damage Adults are small grayish weevils 0.16 inch long. Larvae feed on fibrous roots and chew cavities in main roots but usually do not cause economic damage to alfalfa.
Management-chemical control
- 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. For adult control only. Do not exceed 0.06 lb ai/A per cutting 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. For adult control only. Do not exceed 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.