Alfalfa hay-Alfalfa and/or cabbage looper

Autographa californica and Trichoplusia ni

Pest description and crop damage The adult moth is gray to light brown, and the front wing has a white teardrop-shaped mark. Larvae have three pairs of abdominal prolegs, two pairs in the middle of the abdomen and one pair of anal prolegs, are light green, and have a pale head. Fully developed larvae are about 1 inch long and move in a looping, or "inchworm," fashion. Larvae rarely need chemical control in alfalfa. For additional information, see: http://horticulture.oregonstate.edu/content/cabbage-looper-alfalfa-looper.

Sampling and thresholds Ten or more nonparasitized larvae per 90° sweep, sometimes called a straight-line sweep.

Management-chemical control

  • alpha-cypermethrin (Fastac EC) at 0.014 to 0.025 lb ai/a. PHI 3 days of cutting or grazing. REI 12 hr. Retreatment interval 7 days. Do not exceed 0.075 lb ai/a per season.
  • azadirachtin (Aza-Direct, Neemix 4.5). See specific labels for rates. PHI 0 days. REI 4 hr. Aza-direct and Neemix 4.5 are OMRI-listed for organic use.
  • Bacillus thuringiensis (numerous products) at 0.25 to 1.5 lb ai/a. PHI 0 days. REI 4 hr. Most effective on small caterpillars; use highest labeled rate for large larvae. Evening applications increase efficacy. A spreader sticker may improve performance. OMRI-listed for organic use. (Group 11)
  • beta-cyfluthrin (Baythroid XL) at 0.0065 to 0.022 lb ai/a. PHI 7 days for grazing or cutting. REI 12 hr. Do not exceed 0.044 lb ai/a per cutting or 0.175 lb ai/a per season. Retreatment interval 5 days. This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. (Group 3A)
  • chlorantraniliprole (Coragen) at 0.045 to 0.098 lb ai/a. PHI 0 days. REI 4 hr. Do not exceed 0.2 lb ai/a or 4 applications per season or 1 application per cutting. Retreatment interval 3 days. (Group 28)
  • chlorantraniliprole/lambda-cyhalothrin (Besiege) at 0.049 to 0.078 lb ai/a. PHI 1 day for forage and 7 days for hay. REI 24 hr. Minimum of 5 days between applications. Do not exceed 0.12 lb ai of products containing lambda-cyhalothrin or 0.2 lb ai of chlorantraniliprole-containing foliar products per acre per growing season. This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. (Groups 28 and 3A)
  • chlorpyrifos/gamma cyhalothrin (Cobalt) at 0.38 to 0.76 lb ai/a. PHI 14 at low rate to 21 days at 0.52 lb ai/a or above. REI 24 hr. Do not apply Cobalt or any other product containing chlorpyrifos more than once per cutting nor more than 4 times per season. This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. (Groups 1B and 3A)
  • cyfluthrin (Tombstone) at 0.013 to 0.044 025 lb ai/a. PHI 7 days for grazing or cutting. REI 12 hr. Retreatment interval 5 days. Do not exceed 0.088 lb ai/a per cutting or 0.35 lb ai/a per season. This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. (Group 3A)
  • flubendiamide (Belt SC) at 0.063 to 0.125 lb ai/a. PHI 0 days. REI 12 hr. Retreatment interval 21 days. Do not exceed 0.375 lb ai/a per season. (Group 28)
  • gamma-cyhalothrin (Declare) at 0.0075 to 0.0125 lb ai/a. PHI 1 day for forage harvest or 7 days for hay harvest. REI 24 hr. Do not exceed 0.015 lb ai/a per cutting or 0.06 lb ai/a per season. Refer to product labels application limits if products containing gamma-cyhalothrin and products containing lambda-cyhalothrin are to be used in the same season. This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. (Group 3A)
  • indoxacarb (Steward supp label) at 0.065 to 0.11 lb ai/a. PHI 7 days for cutting. REI 12 hr. Do not exceed one application per cutting or 0.44 lb ai/a per season. This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. May be applied to alfalfa through overhead sprinkler systems. (Group 22A)
  • lambda-cyhalothrin (Warrior II) at 0.015 to 0.025 lb ai/a. PHI 1 day for forage harvest or 7 days for hay harvest. REI 24 hr. Apply only to pure stands of alfalfa. Do not exceed 0.03 lb ai/a per cutting or 0.12 lb ai/a per season. Refer to product labels for application limits if products containing gamma-cyhalothrin and products containing lambda-cyhalothrin are to be used in the same season. This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. (Group 3A)
  • methomyl (Lannate LV) at 0.45 to 0.9 lb ai/a. PHI 7 days for grazing or cutting. REI 48 hr. Do not apply more than 10 times per season or exceed 3.6 lb ai/a per season. This product is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. (Group 1A)
  • methoxyfenozide (Intrepid 2F) at 0.06 to 0.12 lb ai/a. PHI 0 days graze/forage, 7 days hay. REI 4 hr. Do not apply more than once/cutting. Do not apply more than 0.5 lb ai/a per year. (Group 18)
  • permethrin (numerous products) at 0.05 to 0.2 lb ai/a. For use on pure alfalfa stands only. PHI 0 days at 0.1 lb ai/a rate, 14 days if more than 0.1 lb ai/a is used. REI 12 hr. Do not exceed 0.2 lb ai/a per cutting. Retreatment interval 30 days. Permethrin is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. (Group 3A)
  • spinosad (Entrust SC) at 0.031 to 0.063 lb ai/a. PHI 0 days forage; 3 days hay or fodder. REI 4 hr. Only for suppression of alfalfa weevil larvae. Do not exceed 0.186 lb ai/a per season. Do not exceed 6 applications per season. This product is toxic to bees exposed to treatment for 3 hours following treatment. Do not apply this pesticide to blooming, pollen-shedding or nectar-producing parts of plants if bees may forage on the plants during this time period. Entrust is OMRI-listed for organic use. (Group 5)
  • zeta-cypermethrin at 0.028 to 0.05 lb ai/a (Mustang), or at 0.014 to 0.025 lb ai/a (Mustang Maxx). PHI 3 days for cutting or grazing, 7 days for harvesting seed. REI 12 hr. Retreatment interval 7 days. Do not use more than 0.05 lb ai/a per cutting or more than 0.15 lb ai/a per season (Mustang) or 0.025 lb ai/a per cutting or 0.075 lb ai/a per season (Mustang Maxx). These products are highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply this product or allow it to drift to blooming crops if bees are visiting the treatment area. (Group 3A)