Pasture and grass hay-Black grass bug

Labops hesperius and other Labops spp.
Irbisia pacifica and other Irbisia spp.

Pest description and crop damage Insect is grayish black with silvery scales, about 0.25 inch long, and somewhat pear-shaped. Adults have prominent compound eyes and can have shortened or absent wings. Black grass bugs will feed on a variety of range grasses (e.g., wheatgrass, brome grass, orchardgrass, bluegrass) and field crops (e.g., barley, wheat, rye, oats). Great Basin wildrye and wheatgrasses are preferred if available, especially blue bunch wheatgrass, crested wheatgrass, and intermediate wheatgrass. Feeding causes pale spots on the leaves of cereals and, when severe, a general yellowish, stippled appearance.

Management-chemical control

  • bifenthrin (Brigade WSB) at 0.1 ai/A. PHI 30 days for forage and grass. Do not apply more than 0.2 lb ai/A per year. REI 12 hr. Retreatment interval 14 days.
  • carbaryl (Sevin 4F) at 0.5 to 1 lb ai/A. PHI 14 days. REI 12 hr. Limit two treatments per year. Retreatment interval 14 days. Do not exceed 3 lb ai/A per year. (See various labels under "Rangeland").
  • chlorantraniliprole/lambda-cyhalothrin (Besiege, Voliam Xpress) at 0.059 to 0.098 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 0.045 lb ai/A per season.
  • lambda cyhalothrin (Warrior II) at 0.015 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.
  • zeta-cypermethrin (Mustang, Mustang Maxx)-Mustang at 0.035 to 0.05 lb ai/A; Mustang Maxx at 0.0175 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.