Alfalfa hay-Cutworm

Includes

Army cutworm (Euxoa auxiliaris)-adults are called "miller moths" 


Clover cutworm (Scotogramma trifolii) 


Granulate cutworm (Feltia subterranea)

Redbacked cutworm (Euxoa ochrogaster) 


Variegated cutworm (Peridroma saucia)

Pest description and crop damage Cutworms usually are dull gray, brown, or black and may be striped or spotted. They often curl up when disturbed. They usually feed at night and by day are found under leaves or in the soil at moisture level. Cutworms can kill seedlings and reduce stands. If alfalfa fields do not "green up" in the spring, or are slow to regrow after cutting in the fall, look for cutworms. Small populations (less than one larva/yd) can damage new seedlings. Cutworms are primarily a pest of alfalfa and clovers, but they attack other legumes also. Army cutworms, redbacked and variegated cutworms begin feeding in the fall and overwinter as half-grown larvae in grain and hay fields. Most damage occurs as caterpillars complete their development in spring. overwinter as partially grown caterpillars. In mild winter years, be aware of large populations that can cause significant damage in late winter and early spring. In mild winter years, be aware of large populations that can cause significant damage in late winter and early spring. Variegated cutworm has an overwinter generation similar to the army cutworm and a midsummer generation. Redbacked cutworms overwinter as eggs and caterpillars commence feeding in late winter to early spring. For additional information, see: http://www.extension.uidaho.edu/forage/Proceedings/2004%20Proceedings%20...

Management-chemical control

When convenient, irrigate the field before treating for redbacked or army cutworms. This brings larvae to the surface, making control easier. Applications in late evening, when larvae usually feed above ground, are most effective.

  • 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. 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)
  • 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 product/a. PHI 0 days. REI 4 hr. Most effective on small caterpillars, but use highest recommended rate for fully developed ones. A spreader-sticker may improve performance. Some formulations are OMRI-listed for organic use. (Group 11)
  • beta-cyfluthrin (Baythroid XL) at 0.0065 to 0.0125 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 total 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)
  • carbaryl (numerous products) at 1 to 1.5 lb ai/a. PHI 7 days for grazing or cutting. REI 12 hr. Do not apply more than once per cutting. Carbaryl may burn or yellow hay under some conditions (wet foliage, high humidity). Latex-based formulations, such as Sevin XLR Plus, are less hazardous to bees. (Group 1A)
  • 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 lambda-cyhalothrin or 0.2 lb ai of chlorantraniliprole-containing foliar products per acre per growing 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. (Groups 28 and 3A)
  • chlorpyrifos (numerous products) at 0.5 to 1 lb ai/a. PHI for grazing or cutting is 7 days at 0.25 lb ai/a or 14 days at 0.5 lb ai/a or 21 days for rates above 0.5 lb ai/a. REI 24 hr. Do not apply any chlorpyrifos products more than four times per season or more than once per cutting. Do not reapply within 10 days of the first application. Certain products can be chemigated by sprinkler irrigation. Minor phytotoxicity is possible on new growth. Chlorpyrifos 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 1B)
  • chlorpyrifos/gamma-cyhalothrin (Cobalt) at 0.26 to 0.52 lb ai/a. PHI 14 to 21 days. REI 24 hr. Do not apply Cobalt nor any other product containing chlorpyrifos more than once per cutting nor more than 4 times 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 1B and 3A)
  • Chromobacterium subtsugae (Grandevo) at 0.3 to 0.9 lb ai/a per 100 gal. PHI 0 days. REI 4 hr.
  • cyfluthrin (Tombstone) at 0.013 to 0.025 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 total 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 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)
  • indoxacarb (Steward) at 0.065 to 0.11 lb ai/a. PHI 7 days for grazing or 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. (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. Do not apply when bees are actively foraging. 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; other products) at 0.23 to 0.9 lb ai/a. PHI 7 days for grazing or cutting. REI 48 hr. Do not exceed 10 applications or more than 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)
  • permethrin (numerous products) at 0.05 to 0.2 lb ai/a. PHI 0 days at 0.1 lb ai/a or less, 14 days at more than 0.1 lb ai/a. 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. Some formulations are 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 Max EC or 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 Max, Mustang Maxx). Zeta-cypermethrin is highly toxic to bees exposed to direct treatment or residues on blooming crops or weeds. Do not apply product or allow it to drift to blooming crops if bees are visiting the treatment area. (Group 3A)