Collard and kale-Armyworm, cutworm, and looper

Includes

Beet armyworm (Spodoptera exigua)
Bertha armyworm (Mamestra configurata)
Western yellowstriped armyworm (Spodoptera praefica)
Black cutworm (Agotis ipsilon)
Variegated cutworm (Peridroma saucia)
Alfalfa looper (Autographa californica)
Cabbage looper (Trichoplusia ni)

Pest description and crop damage Several species of armyworm, cutworm, and looper attack collards and kale. Armyworm larvae feed in colonies shortly after hatching and skeletonize leaves. As they grow larger, they tend to disperse and consume irregular patches of foliage or entire leaves. Their fecal material (frass) contaminates harvested portions of the crop.

Cutworms do most of their feeding near the soil line, often cutting off seedlings at ground level. The variegated cutworm in particular also climbs up into plants to feed. Cabbage looper larvae feed on leaves, causing ragged-edge holes in the leaf and on the leaf margins. The major damage caused by larvae and pupae is contamination of the heads of cole crops.

Biology and life history

See:

Management-cultural control

Weed control is important. Lambsquarters and wild mustard attract egg-laying females and provide a source of food for larvae. Fall tillage can help destroy overwintering pupae.

Home gardeners: Control weeds, grasses, and debris in the vegetable garden that provide cover; hand-pick cutworm larvae, using a flashlight to find them, if practical. Scratch the soil at the base of plants to find larvae in the daytime.

Management-chemical control: HOME USE

  • acetamiprid
  • 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.
  • permethrin
  • plant-derived essential oils (rosemary, peppermint etc.)-Some formulations are OMRI-listed for organic use.
  • 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. 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 0.007 to 0.025 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 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/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 as a foliar application. 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 ai/a per season.
  • borate complex (Prev-Am Ultra) applied as a 0.8% 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 3 treatments per year. Do not exceed 6 lb ai/a per crop. Retreatment interval 7 days.
  • carbaryl (Sevin 5 Bait) at 2 lb ai/a. PHI 14 days. REI 12 hr. Limit 3 treatments per year. Do not exceed 6 lb ai/a per crop. Retreatment interval 7 days. Limit 3 applications.
  • 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.
  • chlorpyrifos (Lorsban Advanced 2ee) at 2.1 lb ai/a for cutworms only. PHI 30 days. REI 24 hr. Apply at planting. Use only once per year. OR and WA 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 14 days. REI 12 hr. Do not exceed 92 lb ai/a per season. Collards only. OMRI-listed for organic use.
  • cyantraniliprole (Exirel) at 0.045 to 0.11 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 0.013 to 0.05 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.
  • diazinon (Diazinon AG500) at 2 to 4 lb ai/a broadcast just before planting. Incorporate immediately. REI 4 days. Cutworms only.
  • emamectin benzoate (Proclaim) at 0.0075 to 0.015 lb ai/a. REI 12 hr. PHI 14 days. 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. Limit 4 treatments per year. Do not exceed 0.26 lb ai/a per crop. Retreatment interval 3 days.
  • malathion (Malathion 8) at 1 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 lb to 0.9 lb ai/a. PHI 10 days. REI 48 hr. Do not exceed 5.4 lb ai/a collards per year. 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 1.88 lb ai/a. PHI 1 day. REI 48 hr. Retreatment interval 7 days. Limit 5 treatments per season. Do not exceed 9.4 lb ai/a per year. Loopers only.
  • 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) at 0.047 to 0.156 lb ai/a. PHI 1 day. REI 4 hr. Do not exceed six applications or 0.45 lb ai/a per crop. Some formulations are OMRI-listed for organic use.
  • tebufenozide (Confirm) 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. 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 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.