Small grain-Barley thrips

Limothrips denticornis

Pest description and crop damage Black or brownish, winged or wingless, small slender insects between 0.03 and 0.0625 inch long. Thrips feed on the cell contents of the plant foliage which would result in whitish/silverish look of the infested plants and fields. When abundant, they may injure flowers and reduce yields. Because of their small size they are hard to locate. Gently unroll leaves or tap plants on a white background to inspect for their presence.

Management-chemical control

Foliar spray

  • alpha-cypermethrin (Fastac EC) at 0.02 to 0.025 lb ai/A. PHI 14 days for grain, forage and hay. REI 12 hr. Retreatment interval 14 days. Do not exceed 0.075 lb ai/A per season. Wheat and triticale.
  • azadirachtin (Aza-Direct, Ecozin 3EC) at 0.0125 to 0.043 lb ai/A. PHI 0 day. REI 4 hr. Retreatment interval 7 days. Best results can be obtained following 2-3 applications made at 7- to 10-day intervals. Some formulations are OMRI-listed for organic use.
  • Chromobacterium subtsugae (Grandevo WDG) at 0.6 to 0.9 lb ai/A. PHI 0 days. REI 4 hr. OMRI-listed for organic use.
  • fenpropathrin (Danitol) at 0.2 lb ai/A. REI 24 hr. Do not exceed 0.2 lb ai/A per season. One treatment per season. Apply before the boot stage of growth. Barley only.
  • pyrethrin-There are several pesticides containing various amounts of pyrethrins. Check each label for the use and amount needed. Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin (Mustang) at 0.04 to 0.05 lb ai/A. PHI 14 days for grain, forage, and hay. REI 12 hr. Retreatment interval 14 days. Do not exceed 0.25 lb ai/A (0.125 lb ai/A for MustangMaxx) per year.