Pest description and crop damage Larvae are gray grubs that feed underground, on roots and crowns, from October through May. Older larvae may feed above ground on stems and leaves during the night. Large numbers can thin stands in old pastures and kill seedlings in new stands.
- beta-cyfluthrin (Baythroid XL, Warrior and Mustang) has given effective control of these pests when applied to control other labeled pests that occur at the same timing as for these products. Research in Oregon has shown it to be effective on this particular pest when used at higher-range label rates for other pests. Oregon and Washington only.
- chlorantraniliprole/lambda-cyhalothrin (Besiege, Voliam Xpress) at 0.59 to 0.98 lb ai/a. PHI 0 days for grazing or cut for forage; 7 days for cut grass to be dried and harvested for hay. Retreatment interval 7 days. REI 12 hr. Do not exceed 0.09 lb ai/a lambda-cyhalothrin or 0.2 lb ai/a chlorantraniliprole.
- gamma-cyhalothrin (Declare) at 0.01 to 0.015 lb ai/a. PHI 0 days for grazing or cut for forage; 7 days for cut grass to be dried and harvested. REI 24 hr. Do not exceed 0.45 lb ai/a per season.
- lambda-cyhalothrin (Warrior II) at 0.02 to 0.03 lb ai/a. PHI 0 days for grazing and forage; 7 days to be dried for hay. REI 24 hr. Do not exceed 0.03 lb ai/a per cutting or 0.09 lb ai/a per season.
- malathion (Fyfanon ULV) at 0.48 to 0.62 lb ai/a. PHI 0 days. REI 12 hr. Adults only. Limit 1 treatment per cutting.