Rhubarb-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

See:

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

Apply any one of these materials to the soil surface at first sign of cutworm activity. Consult label. Minimum preharvest interval (PHI) varies with crop. Difficult to control. Where cutworms are on the soil surface, a carbaryl drench, when bees are not present, may help. Beans, tomatoes, and late corn are most often "hoed" by cutworms. Attack varies in severity with locality and year.

  • acetamiprid
  • azadirachtin (neem oil)-Some formulations are OMRI-listed for organic use.
  • carbaryl
  • cyfluthrin
  • insecticidal soap-May require several applications. 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.
  • permethrin
  • plant-derived essential oils (rosemary, peppermint, etc.)-These have some efficacy against lepidopteran larvae. 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 (Dipel Pro) at 0.12 to 1.5 lb/a. PHI 0 days. REI 4 hr. Acts slowly; 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 0.007 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.
  • bifenthrin (Brigade WSB) at 0.033 to 0.1 lb ai/a. PHI 7 days. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.5 lb ai/a per season.
  • Burkholderia spp. (Venerate XC) at 1 to 4 qt product per acre. PHI 0 day. REI 4 hr.
  • carbaryl (Sevin 4F) at 1 to 2 lb ai/a. PHI 14 days. REI 12 hr. Retreatment interval 7 days. Limit 5 treatments per year. Do not exceed 6 lb ai/a per season.
  • chlorantraniliprole (Coragen) at 0.045 to 0.098 lb ai/a at plant, drip, foliar. PHI 1 day. REI 4 hr. Retreatment interval 3 days for foliar and 10 days for 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.
  • Chromobacterium subtsugae (Grandevo) at 0.3 to 0.9 lb ai/a per 100 gal. PHI 0 days. REI 4 hr. Some formulations are 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.
  • 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.
  • 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.
  • indoxacarb (Avaunt) at 0.065 lb ai/a. PHI 3 days. REI 12 hr. Do not exceed 0.26 lb ai/a per crop. Retreatment interval 3 days. Limit 4 treatments.
  • methoxyfenozide (Intrepid 2F) at 0.06 to 0.12 lb ai/a for early-season, and 0.12 to 0.16 ai/a for mid- to late-season. REI 4 hr. PHI 1 day. Do not exceed 1 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 0.2 lb ai/a per season.
  • spinetoram (Radiant SC) at 0.039 to 0.078 lb ai/a. PHI 1 day. Retreatment interval 4 days. Do not exceed 0.266 lb ai/a per season. Limit 6 treatment per season.
  • spinosad (Entrust SC) at 0.05 to 0.12 lb ai/a. PHI 1 day. REI 4 hr. Do not exceed 0.45 lb ai/a per crop. Limit 6 treatments per season. Entrust SC is OMRI-listed for organic use.
  • tebufenozide (Confirm 2F) at 0.09 to 0.12 lb ai/a early-season, and 0.12 lb ai/a mid- to late-season. PHI 7 days. REI 4 hr. Do not exceed 0.625 lb ai/a per season. Reapplication on a 10- to 14-day schedule may be necessary for heavy infestations. Use of a spreader-binder is recommended.
  • thiamethoxam/chlorantraniliprole (Durivo) at 0.194 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. Do not exceed 0.3 lb ai/a per season.

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