Collard and kale-Imported cabbageworm

Pieris rapae

Pest description, crop damage and life history

See:

Pest monitoring The following information is from California but is generally applicable in the Pacific Northwest: Cabbageworms can be monitored at the same time as cabbage loopers. Sample 25 plants selected randomly throughout the field. Although treatment levels combine the two species, cabbageworms may be harder to find because of their smaller size and their inconspicuous coloring. Look for small larvae and eggs on the undersides of leaves. Larger worms feed toward the center of the plant, often near the midribs of leaves. Good clues to cabbageworm presence include their greenish brown fecal pellets or many white cabbage butterflies fluttering around the field (check for eggs in a few days).

Base treatment on numbers of healthy larvae present. Treat seedlings or small plants if populations of medium-sized to large caterpillars are high enough to stunt growth. Treatment prior to harvest is necessary to prevent contamination for harvested product.

Management-biological control

Natural enemies can assist significantly in the control of imported cabbageworm. Important parasites include the pupal, larval, and egg parasites in the Trichogramma genus, as well as tachinid flies. Timely mass releases of commercially available trichogramma during peak flight can be an effective control agent. Viruses and bacterial diseases are also sometimes important control factors in the field.

Where possible, use Bacillus thuringiensis (Bt) to avoid adverse impact on natural enemies. Bt is very effective against imported cabbageworm, especially when applied to young (early-instar) caterpillars.

Management-cultural control

Make new plantings as far as possible from those of the previous year. At the end of the year, harvest crops without delay. Plowing under or destroying plant residues at this time eliminates an important food source for the overwintering generation of cabbageworms.

Management-chemical control: HOME USE

  • azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
  • Bacillus thuringiensis var. kurstaki (Btk)-Some formulations are OMRI-listed for organic use.
  • bifenthrin
  • carbaryl
  • cyfluthrin
  • esfenvalerate-Do not use on kale.
  • kaolin-When applied as a spray to foliage it acts as a repellent to some insect pests. Some formulations OMRI-listed for organic use.
  • malathion
  • permethrin
  • pyrethrins-Some formulations are OMRI-listed for organic use.
  • spinosad-Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin

Management-chemical control: COMMERCIAL USE

  • alpha-cypermethrin (Fastac EC) at 0.014 to 0.025 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.075 lb ai/a per season.
  • Bacillus thuringiensis (Javelin) 0.12 to 1.5 lb/a. PHI 0 days. REI 4 hr. Slow acting. May need multiple applications. Add an appropriate spreader-sticker to enhance control. Most effective on small larvae. Some formulations are OMRI-listed for organic use.
  • beta-cyfluthrin (Baythroid XL) at 0.013 to 0.019 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/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 0.24 lb ai/a bifenthrin. Retreatment interval 7 days. Maximum 5 treatments only after bloom.
  • bifenthrin (Brigade 2EC, Sniper) at 0.033 to 0.1 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.4 lb ai/a per season.
  • bifenthrin/zeta-cypermethrin (Hero) at 0.04 to 0.1 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.45 lb ai/a per season.
  • borate complex (Prev-Am Ultra) applied as a 0.4% solution. Spray to complete coverage. REI 12 hr. Retreatment interval 7 days. OMRI-listed for organic use.
  • Burkholderia spp. (Venerate XC) at 1 to 8 quarts/a product. PHI 0 days. REI 4 hr. OMRI-listed for organic use.
  • carbaryl (Sevin 4F) at 1 to 2 lb ai/a. PHI 14 days. REI 12 hr. Limit 4 treatments per year. Do not exceed 6 lb ai/a per crop. Retreatment interval 7 days.
  • chlorantraniliprole (Coragen) at 0.045 to 0.098 lb ai/a as soil, chemigation or foliar treatment. PHI 3 days. REI 4 hr. Limit 4 treatments per crop. Retreatment interval 3 days foliar, 10 days drip chemigation. Do not exceed 0.2 lb ai/a per season.
  • chlorantraniliprole/thiamethoxam (Voliam Flexi) at 0.1 to 0.175 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.172 lb ai of thiamethoxam or 0.2 lb ai of chlorantraniliprole per acre per growing season.
  • chlorpyrifos (Lorsban 75WG) at 0.5 to 1 lb ai/a. PHI 21 days. REI 24 hr. Do not exceed 3 applications per year. Retreatment interval 10 days.
  • Chromobacterium subtsugae (Grandevo) at 0.3 to 0.9 lb ai/a per 100 gal. PHI 0 days. REI 4 hr. OMRI-listed for organic use.
  • cryolite (Kryocide) at 7.7 to 15.4 lb ai/a. PHI 14 days. REI 12 hr. Do not exceed 92 lb ai/a per season. Some formulations are OMRI-listed for organic use. Collards only.
  • cyantraniliprole (Exirel) at 0.045 to 0.88 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 5 days. Do not exceed 0.4 lb ai/a per year. Limit 6 treatments per year.
  • cyclaniliprole (Harvanta 50SL) at 0.036 to 0.054 lb ai/a. REI 4 hr. PHI 1 day. Limit 3 treatments per crop. Retreatment interval 5 days. Do not exceed 0.22 lb ai/a per year.
  • cyfluthrin (Tombstone) at 0.025 to 0.038 lb ai/a. PHI 0 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.2 lb ai/a per season.
  • cyfluthrin/imidacloprid (Leverage 2.7) at 0.08 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.17 lb ai/a cyfluthrin or 0.24 lb ai/a imidacloprid per year.
  • cypermethrin (Holster) at 0.05 to 0.1 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.4 lb ai/a per year.
  • emamectin benzoate (Proclaim) at 0.0075 to 0.015 lb ai/a. PHI 14 days. REI 12 hr. Do not exceed 0.09 lb ai/a per season. Retreatment interval 7 days. Do not graze.
  • esfenvalerate (Asana XL) at 0.03 to 0.05 lb ai/a. PHI 7 days. REI 12 hr. Do not feed crop residue. Do not exceed 0.2 lb ai/a per year. Collards only.
  • GS-omega/kappa-Hxtx-Hv1a (Spear Biological Insecticide) at 0.8 lb ai/a. PHI 0 days. REI 4 hr. Do not exceed 2 lb ai/a per year.
  • indoxacarb (Avaunt) at 0.045 to 0.065 lb ai/a. PHI 3 days. REI 12 hr. Do not exceed 0.26 lb ai/a per crop. Limit 4 treatments per year. Retreatment interval 3 days.
  • malathion (Malathion 8) at 1.0 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval kale 5 days, collards 7 days. Limit 3 applications.
  • methomyl (Lannate SP) at 0.45 to 0.9 lb ai/a. PHI 10 days. REI 48 hr. Do not exceed 5.4 lb ai/a collards per year. Fresh market Collards only.
  • methoxyfenozide (Intrepid 2F) at 0.06 to 0.12 lb ai/a for early-season application or at 0.12 to 0.16 lb ai/a for mid- to late-season application. PHI 1 day. REI 4 hr. Do not exceed 1 lb ai/a per season.
  • naled (Dibrom 8) at 0.94 lb ai/a. PHI 1 day. REI 48 hr. Do not exceed 9.4 lb ai/a per year. Retreatment interval 7 days
  • spinetoram (Radiant SC) at 0.039 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 0.047 to 0.094 lb ai/a. PHI 1 day. REI 4 hr. Do not exceed six applications or 0.45 lb ai/a per crop. Entrust SC is OMRI-listed for organic use.
  • tebufenozide (Confirm 2F) at 0.09 to 0.12 lb ai/a early-year; 0.12 lb ai/a mid- to late-year. PHI 7 days. REI 4 hr. Do not exceed 0.12 lb ai/a per application or 0.625 lb ai/a per year. Retreatment interval 10 days. Use of a surfactant is recommended.
  • thiamethoxam/chlorantraniliprole (Durivo) at 0.195 to 0.257 lb ai/a applied to the soil. PHI 30 days. REI 12 hr. Do not 0.172 lb ai of thiamethoxam or 0.2 lb ai of chlorantraniliprole per acre per growing season.
  • zeta-cypermethrin (Mustang) at 0.028 to 0.05 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.3 lb ai/a per season.