Bean, snap-Armyworm and cutworm

Includes

Beet armyworm (Spodoptera exigua)
Bertha armyworm (Mamestra configurata)
Western yellowstriped armyworm (Spodoptera praefica)
Black cutworm (Agotis ipsilon)
Variegated cutworm (Peridroma saucia)

Pest description, crop damage 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.
  • Beauvaria bassiana-Some formulations are OMRI-listed for organic use.
  • bifenthrin
  • carbaryl
  • esfenvalerate
  • gamma-cyhalothrin
  • insecticidal soap (may require several applications)-Some formulations are OMRI-listed for organic use.
  • permethrin
  • plant essential oils (peppermint, 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

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.

  • alpha-cypermethrin (Fastac EC) at 0.008 to 0.025 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 5 days. Do not exceed 0.075 lb ai/a per season.
  • Bacillus thuringiensis (Javelin WG) at 0.12 to 1.5 lb ai/a. PHI 4 to 12 hr. Armyworms only. Add an appropriate spreader-sticker to enhance control. Most effective on small larvae. Some formulations are OMRI-listed for organic use.
  • bifenthrin (Sniper) at 0.033 to 0.1 lb ai/a. PHI 3 days. REI 12 hr. Do not exceed 0.2 lb ai/a per season.
  • bifenthrin/IBA (Empower 2) at 0.04 to 0.1 lb ai/a. PHI 3 days. REI 5 days. Do not exceed 0.2 lb ai/a per season.
  • bifenthrin/imidacloprid (Brigadier) at 0.0875 lb ai/a. PHI 7 days. REI 12 hr. Do not exceed 0.13 lb ai/a imidacloprid and 0.13 lb ai/a bifenthrin per season. Retreatment interval 7 days.
  • bifenthrin/zeta-cypermethrin (Hero) at 0.04 to 0.1 lb ai/a. PHI 3 days. REI 12 hr. Retreatment interval 5 days. Do not exceed 0.266 lb/a per season.
  • borate complex (Prev-Am Ultra) applied as a 0.4% to 0.8% solution. Spray to complete coverage. PHI: see label. REI 12 hr. Retreatment interval 4 days. OMRI-listed for organic use.
  • carbaryl (Sevin 4F) at 1 to 1.5 lb ai/a. PHI 3 days. REI 12 hr. Do not exceed 6 lb ai/a per crop. Retreatment interval 7 days. Toxic in aquatic habitats. Do not apply carbaryl dust to blooming weeds because of severe hazard to pollinating bees. Latex-based formulations, such as Sevin XLR Plus, are less hazardous to bees.
  • chlorantraniliprole (Coragen) at 0.065 to 0.098 lb ai/a. PHI 1 day. REI 4 hr. Limit 4 treatments. Retreatment interval 3 days. do not exceed 0.6 lb ai/a per season.
  • chlorantraniliprole/lambda-cyhalothrin (Besiege) at 0.05 to 0.1 lb ai/a. PHI 7 days. REI 24 hr. Retreatment interval 5 days. Do not exceed a total of 31.0 fl oz of Besiege or 0.12 lb ai of lambda-cyhalothrin or 0.2 lb ai of chlorantraniliprole per acre per growing season. Do not graze livestock or harvest vines for forage or hay.
  • 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.
  • diazinon (Diazinon AG500, Adama) at 2 to 4 lb ai/a. REI 3 days. Broadcast just before planting and immediately incorporate into the soil.
  • esfenvalerate (Asana XL) at 0.03 to 0.05 lb ai/a. PHI 3 days. REI 12 hr. Do not exceed 0.2 lb ai/a per season. Do not allow livestock to graze treated bean fields. Do not harvest treated bean vines for livestock forage, fodder, or hay.
  • gamma-cyhalothrin (Declare) at 0.01 to 0.015 lb/a. PHI 7 days. REI 24 hr. Retreatment interval 5 days. Do not graze. Do not exceed 0.06 lb ai/a per season. Do not graze livestock in treated areas or harvest vines for forage or hay.
  • GS-omega/kappa-Hxtx-Hv1a (Spear Biological Insecticide) at 0.8 lb ai/a. PHI 0 day. REI 4 hr.
  • lambda-cyhalothrin (Warrior II) at 0.02 to 0.03 lb ai/a. PHI 7 days. REI 24 hr. Retreatment interval 5 days. Do not exceed 0.12 lb ai/a per season. Do not graze livestock in treated areas or harvest vines for forage or hay.
  • methomyl (Lannate SP) at 0.45 to 0.9 lb ai/a. PHI 1 to 3 days for beans, 3 days for feeding vines, 7 days for hay. REI 48 hr. Do not exceed 4.5 lb ai/a per season.
  • methoxyfenozide (Intrepid) at 0.06 to 0.12 lb ai/a for early season and 0.12 to 0.25 lb ai/a for mid to late season applications. PHI 7 days. REI 4 hr. Retreatment interval 7 days. Do not exceed 1 lb ai/a or four applications per season.
  • novaluron (Rimon EC) at 0.039 to 0.078 lb ai/a. PHI 1 day. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.23 lb ai/a per season.
  • spinetoram (Radiant SC) at 0.0313 to .0625 lb ai/a. PHI 3 days. REI 4 hr. Retreatment interval 4 days. Do not exceed 6 applications or 0.219 lb ai/a per season. Follow resistance management procedures on the label. Armyworm only.
  • spinosad (Success) at 0.06 to 0.09 lb ai/a. PHI 3 days. REI 4 hr. Treat eggs at hatch and small larvae. Do not exceed three times in a 30-day period. Do not exceed six applications or 0.45 lb ai/a per crop. Do not feed forage or hay to livestock. Armyworm only. Spinosad takes several days to achieve full effect. Monitor fields and pest populations carefully. Multiple applications may be necessary. Some formulations are OMRI-listed for organic use.

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