Broccoli, Brussels sprout, cabbage, cauliflower-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-size to large caterpillars are high enough to stunt growth. Prior to heading, well-established plants do not need to be treated unless you find more than nine small to medium-size larvae per plant. Treat just before heading or at Brussels sprout formation if counts show more than one caterpillar in 25 plants.

An action threshold to prevent contamination of broccoli heads by cabbageworm larvae has not been established in Oregon. If large cabbageworm larvae are present in the field when broccoli heads begin to elongate, treatment is justified to prevent larvae from moving up into the heads in search of pupation sites. Preharvest clean up sprays alone generally do a poor job of removing the large cabbageworms once they have established themselves in the broccoli head.

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

Management-cultural control

The use of resistant cabbage varieties such as Mammoth Red Rock, Chieftain Savoy, and Savoy Perfection Drumhead provides some protection, but not complete 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
  • cyhalothrin
  • esfenvalerate-Do not use on Brussels sprout.
  • gamma-cyhalothrin
  • insecticidal soap-Some formulations are OMRI-listed for organic use.
  • kaolin-Applied as a spray to foliage, it acts as a repellent to some insect pests. Some formulations are OMRI-listed for organic use.
  • lambda-cyhalothrin
  • malathion
  • permethrin
  • plant essential oils (rosemary, etc.)-Some have demonstrated efficacy against lepidopteran larvae. Some formulations are OMRI-listed for organic use.
  • pyrethrins (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

  • acephate (Acephate 90WDG) at1.0 lb ai/a. PHI 14 days. REI 24 hr. Do not exceed 2 lb ai/a per season. Retreatment interval 7 days. Do not feed trimmings to livestock or allow animals to graze in treated areas. Brussels sprout and cauliflower only.
  • alpha-cypermethrin (Fastac EC) at 0.02 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 (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.
  • 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/a per season. Limit 5 applications after bloom.
  • borate complex (Prev-Am) at 0.4% solution. REI 12 hr. Spray to complete coverage. 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 3 days. REI 12 hr. Do not exceed 6 lb ai/a per crop. Retreatment interval 7 days. Do not exceed 4 treatments per year. Toxic in aquatic habitats. Latex-based formulations, such as Sevin XLR Plus, are less hazardous to bees.
  • chlorantraniliprole (Coragen) at 0.045 to 0.098 lb ai/a at planting; via drip irrigation; as foliar. PHI 3 days. REI 4 hr. Retreatment interval 3 days for foliar and 10 days for drip. Do not exceed 0.2 lb ai/a per season. Consult label for details.
  • chlorantraniliprole/lambda-cyhalothrin (Voliam Xpress) at 0.049 to 0.078 lb ai/a. 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. Retreatment interval 7. 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, but 3 days for cauliflower. Do not exceed 3 treatments per season. Retreatment interval 10 days. Toxic to fish.
  • chlorpyrifos+gamma-cyhalothrin (Cobalt) at 0.26 to 0.52 lb ai/a. PHI 21 days. REI 24 hr. Limit 3 applications of chlorpyrifos products. Retreatment interval 10 days. Do not exceed 2.25 lb ai/a per year. Brussels sprout only.
  • 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 7 days for broccoli, cauliflower, and Brussels sprout, and 14 days for cabbage. REI 12 hr. Do not exceed 92 lb ai/a per season. OMRI-listed for organic use.
  • cyantraniliprole (Exirel) at 0.045 to 0.088 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 5 days. Limit 6 treatments per year. Do not exceed 0.4 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/a per season. Toxic to bees.
  • emamectin benzoate (Proclaim) at 0.008 to 0.015 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.09 lb ai/a per season. Do not allow livestock to graze in treated areas.
  • esfenvalerate (Asana XL) at 0.015 to 0.03 lb ai/a. PHI 3 days. REI 12 hr. Do not use on Brussels sprout. Do not exceed 0.4 lb ai/a per year.
  • fenpropathrin (Danitol) at 0.2 to 0.3 lb ai/a. PHI 7 days. REI 24 hr. Do not exceed 0.8 lb ai/a per season.
  • flubendiamide (Synapse WG) at 0.045 to 0.075 lb ai/a. PHI 1 day. REI 12 hr. Do not exceed 0.225 lb ai/a per season. Retreatment interval 5 days.
  • flubendiamide + buprofenzin (Vetica) at 0.21 to 0.42 lb ai/a. PHI 1 day. REI 12 hr. Do not exceed 0.83 lb ai/a per season. Retreatment interval 7 days. Limit 2 treatments per crop.
  • gamma-cyhalothrin (Declare) at 0.0075 to 0.0125 lb ai/a. PHI 1 day. REI 24 hr. Do not exceed 0.12 lb ai/a per season. Toxic to bees.
  • indoxacarb (Avaunt) at 0.045 to 0.065 lb ai/a. PHI 3 days. REI 12 hr. A wetting agent is recommended. Allow at least 3 days between applications. Do not exceed 0.26 lb ai/a per year.
  • lambda-cyhalothrin (Warrior II) at 0.015 to 0.025 lb ai/a. PHI 1 day. REI 24 hr. Retreatment interval 5 days. Do not exceed 0.24 lb ai/a per year.
  • lambda-cyhalothrin + thiamethoxam (Endigo ZC) at 0.064 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 1.5 lb ai/a. PHI 2 days broccoli, Brussels sprout, cauliflower; 7 days for cabbage. REI 48 hr. Retreatment interval 7 days. Limit 2 treatments per year.
  • methomyl (Lannate SP) at 0.23 to 0.9 lb ai/a. PHI 3 days for broccoli, cauliflower, and Brussels sprout; 1 day for cabbage; 10 days for Chinese cabbage. REI 48 hr. Do not annually exceed 5.4 lb ai/a for Brussels sprout, 6.3 lb ai/a for broccoli, and 7.2 lb ai/a for cabbage and cauliflower. Add a surfactant to improve coverage.
  • methoxyfenozide (Intrepid 2F) at 0.06 to 0.12 lb ai/a for early-season application and 0.12 to 0.16 lb ai/a for mid- to late-season application, or heavy infestation. PHI 1 day. REI 4 hr. Adding adjuvant improves performance. Do not exceed 1 lb ai/a per season.
  • naled (Dibrom) 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. Limit 5 applications.
  • novaluron (Rimon EC) at 0.039 to 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.
  • permethrin (Loveland Permethrin) at 0.05 to 0.2 lb ai/a. PHI 1 day. REI 12 hr. Do not exceed 0.8 lb ai/a on broccoli nor 0.4 lb ai/a on cabbage, cauliflower and Brussels sprout per year.
  • 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. Treat eggs at hatch and small larvae. Do not apply more than 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.
  • tebufenozide (Confirm 2F) at 0.09 to 0.12 lb ai/a early year or 0.12 lb ai/a mid to late year. PHI 7 days. REI 4 hr. Do not exceed 0.84 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 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.
  • zeta-cypermethrin (Mustang) at 0.028 to 0.05 lb ai/a. PHI 1 day. REI 12 hr. Do not exceed 0.3 lb ai/a per year. Retreatment interval 7 days.