Oulema melanopus
Pest description and crop damage The cereal leaf beetle is a quarantine pest with adults measuring 0.25 inch long, with a brightly colored, orange-red thorax, yellow legs, and metallic-blue head and elytra (forewings). While damage to pasture grasses is rare, its presence has led to strict interstate movement regulations in states like California. Only grass hay from cereal leaf beetle-free PNW counties or fumigated hay from infested counties is allowed into California. Feeding by both the adults and larvae can lead to "windowpaning" on leaves, reducing photosynthesis and plant vigor.
Management-chemical control
- beta-cyfluthrin (Baythroid XL) at 0.013 to 0.015 lb ai/A. PHI 0 days for grazing or hay. REI 12 hr. Do not exceed 0.089 lb ai/A per season. Retreatment interval 5 days.
- bifenthrin (Brigade 2EC, Discipline 2EC) at 0.05 to 0.1 lb ai/A. PHI 30 days for forage and hay. REI 12 hr. Retreatment interval 14 days. Do not exceed 0.2 lb ai/A per year.
- carbaryl (Sevin 4F) at 1 lb ai/A. PHI 14 days. REI 12 hr. Do not exceed two applications. Retreatment interval 14 days. This pest does not occur on the carbaryl labels but when this general use insecticide is applied to control other pests when CLB is present, control is good.
- chlorantraniliprole/lambda-cyhalothrin (Besiege, Voliam Xpress) at 0.0391 to 0.0652 lb ai/A for chlorantraniliprole and 0.0195 to 0.0325 lb ai/A for lambda-cyhalothrin. 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 0.045 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 (Malathion 5EC) at 1.25 lb ai/A. PHI 0 days. REI 12 hr. One application limit per cutting.
- zeta-cypermethrin (Mustang, Mustang Maxx)-Mustang at 0.028 to 0.05 lb ai/A; Mustang Maxx at 0.014 to 0.025 lb ai/A. PHI 3 days for cutting and grazing; 7 days for seed. REI 12 hr. Do not apply more than 0.05 lb ai per cutting or 0.15 lb ai per season of Mustang or 0.025 lb ai per cutting and 0.075 lb ai per season of Mustang Maxx. Retreatment interval 7 days.