Broccoli, Brussels sprout, cabbage, cauliflower-Thrips

Includes

Western flower thrips (Frankliniella occidentalis)
Corn thrips (Frankliniella williamsi)

Pest description and crop damage Thrips are small insects about 0.03 inch long. Adult thrips have two pairs of narrow wings which are fringed with hairs. Immature thrips are wingless, whitish to yellowish, and are most commonly found on the underside of leaves. High numbers of thrips can cause stunting of small broccoli plants. However, thrips are not all bad. Foliage-feeding thrips are spider mite predators and help control spider mite population buildup in early spring.

Biology and life history Adults overwinter in trash, under bark, and in other protected places. Adults become active in the spring and lay eggs in the tissues of plants. The eggs hatch into nymphs, which begin feeding in flowers, buds, and leaves. When mature, nymphs drop to the ground and molt into adults. Under favorable conditions, a life cycle may require only 2 weeks.

Pest monitoring Treatment is usually not necessary on seedlings, because most plants recover from thrips injury. Thrips are also beneficial at this time because of their role as mite predators.

Management-biological control

Minute pirate bugs play a major role in controlling thrips populations.

Management-cultural control

Thrips populations tend to build up on weeds. Cultivating nearby weedy areas before plants emerge reduces the potential of a thrips problem when the weeds begin to dry out. Cultivating weedy areas after emergence increases thrips problems.

Management-chemical control: HOME USE

  • acetamiprid
  • azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
  • Beauvaria bassiana-Some formulations are OMRI-listed for organic use. Do not use on Brussels sprout or cauliflower.
  • bifenthrin
  • carbaryl
  • cyfluthrin
  • cyhalothrin
  • gamma-cyhalothrin
  • imidacloprid
  • insecticidal soap-Some formulations are OMRI-listed for organic use.
  • lambda-cyhalothrin
  • malathion
  • permethrin
  • pyrethins (often combined with other ingredients)-Some formulations are OMRI-listed for organic use.
  • spinosad-Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin

Management-chemical control: COMMERCIAL USE

  • acetamiprid (Assail 30SG) at 0.075 lb ai/a. PHI 7 days. REI 12 hr. Do not exceed 0.375 lb ai/a or five applications per year.
  • beta-cyfluthrin (Baythroid XL) at 0.007 to 0.0125 lb ai/a. PHI 0 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.1 lb ai/a per season
  • beta-cyfluthrin/imidacloprid (Leverage 360) at 0.07 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.1 lb ai/a beta-cyfluthrin or 0.2 lb ai/a imidacloprid per season.
  • bifenthrin (Brigade WSB, Sniper) at 0.033 to 0.1 lb ai/a. PHI 7 days. REI 12 hr. Do not exceed 0.5 lb ai/a per year. Do not make more than five applications after bloom. Retreatment interval 7 days.
  • bifenthrin/imidacloprid (Brigadier) at 0.06 to 0.095 lb ai/a. PHI 7 days. REI 12 hr. Do not exceed 0.24 lb ai/a imidacloprid and 0.5 lb ai/a bifenthrin. Retreatment interval 7 days. Maximum 5 treatments only after bloom. Adult thrips only.
  • bifenthrin + zeta-cypermethrin (Hero) at 0.1 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.45 lb/a per season. Limit 5 applications after bloom.
  • chlorantraniliprole/lambda-cyhalothrin (Voliam Xpress) at 0.059 to 0.088 lb ai/a (suppression only). PHI 3 days. REI 24 hr. Minimum of 5 days between applications. Do not exceed a total of 31.0 fl oz of Voliam Xpress or 0.18 lb ai of products containing lambda-cyhalothrin or 0.2 lb ai of chlorantraniliprole-containing foliar products per acre per growing season.
  • chlorantraniliprole/thiamethoxam (Voliam Flexi) at 0.1 to 0.175 lb ai/a. PHI 3 days. REI 12 hr. Minimum of 7 days between applications. Do not exceed a total of 14 oz of Voliam Flexi or 0.172 lb ai of thiamethoxam-containing products or 0.2 lb ai of chlorantraniliprole-containing products per acre per growing season.
  • cyfluthrin (Tombstone) at 0.013 to 0.025 lb ai/a. PHI 0 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.2 lb/a per season. Toxic to bees.
  • dinotefuran (Scorpion 35SL) at 0.05 to 0.18 lb ai/a as foliar spray, at 0.23 to 0.27 lb ai/a as soil treatment. PHI 1 day for foliar; 21 days for soil. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.266 lb ai/a foliar or 0.532 lb ai/a soil per season.
  • imidacloprid (Admire Pro) at 0.16 to 0.38 lb ai/a. Soil application only. PHI 21 days. REI 12 hr. Do not exceed 0.38 lb ai/a per year.
  • lambda-cyhalothrin + thiamethoxam (Endigo ZC) at 0.072 lb ai/a. PHI 1 day. REI 24 hr. Retreatment interval 7 days. Do not exceed 0.24 lb ai of lambda-cyhalothrin or 0.172 lb ai/a of thiamethoxam per season.
  • malathion (Gowan Malathion 8) at 1.87 lb ai/a. PHI 3 days broccoli; 7 days for cauliflower, Brussels sprout and cabbage. REI 48 hr. Retreatment interval 7 days. Washington and Oregon only.
  • novaluron (Rimon EC) at 0.078 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.156 lb ai/a per season.
  • oxydemeton methyl (MSR Spray Concentrate) at 0.375 to 0.75 lb ai. PHI 7 days. REI 2 days; 3 days where annual rainfall is less than 25 inches. Do not exceed three applications per year. Cabbage only.
  • spinetoram (Radiant SC) at 0.047 to 0.078 lb ai/a. PHI 1 day. REI 4 hr. Retreatment interval 4 days. Do not exceed six applications or 0.266 lb ai/a per season. Do not apply to seedling cole crops grown for transplant within a greenhouse, shade house, or field plot.
  • spinosad (Success, Entrust SC) at 0.063 to 0.156 lb ai/a. PHI 1 day. REI 4 hr. Treat eggs at hatch and small larvae. Do not exceed three times in a 30-day period. Do not exceed 0.45 lb ai/a or six applications per crop. Entrust SC is OMRI-listed for organic use.
  • thiamethoxam (Actara) at 0.047 to 0.086 lb ai/a. PHI 0 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.172 lb ai/a per season.
  • thiamethoxam (Platinum) at 0.078 to 0.172 lb ai/a soil applied. PHI 30 days. Do not exceed 0.172 lb ai/a per season. Apply to the soil as in-furrow spray, band application, drench, shanked or with irrigation. Platinum and Actara have the same active ingredient; for resistance management, do not follow one with the other.
  • thiamethoxam + chlorantraniliprole (Durivo) at 0.195 to 0.257 lb ai/a applied to the soil. PHI 30 days. REI 12 hr. Do not exceed a total of 13 fl oz of Durivo or 0.172 lb ai of thiamethoxam-containing products or 0.2 lb ai of chlorantraniliprole-containing products per acre per growing season.