Clover hay-Cutworm and armyworm

Bertha armyworm (Mamestra configurata)
Variegated cutworm (Peridroma saucia)

Pest description and crop damage These larvae vary a lot in color. By day, the larger larvae are in soil cracks or under duff or leaves. They commonly feed at night. Small larvae are on foliage during the day and can be sampled with a sweep net. They cut off young plants and feed on the foliage of older plants.

Management-chemical control

  • azadirachtin (Neemix 4.5 IGR) at 0.015 to 0.021 lb ai/a. REI 4 hr. PHI 0 days. OMRI-listed for organic use. Armyworms and loopers only.
  • Bacillus thuringiensis (Javelin) at 0.25 to 1.5 lb/a. PHI 0 days. REI 4 hr. Armyworms only. Add an appropriate spreader-sticker to enhance control. Most effective on small, actively feeding larvae. OMRI-listed for organic use.
  • carbaryl (Carbaryl 4L, Sevin 4F) at 1 to 1.5 lb ai/a. PHI 7 days of harvest or grazing. Use only once per cutting. REI 12 hr. Do not use carbaryl when clover is blooming or when bees are foraging actively.
  • chlorantraniliprole (Coragen, Prevathon) at 0.045 to 0.098 lb ai/a. PHI 0 days. REI 4 hr. Do not exceed 0.2 lb ai or 4 applications per season.
  • Chromobacterium subtsugae (Grandevo) at 1 to 3 lb product per 100 gal/acre. PHI 0 days. REI 4 hr. OMRI-listed for organic use.
  • malathion (Drexel Malathion 5EC) at 1.25 lb ai/a. PHI 0 days. Retreatment interval 14 days. REI 12 hr. Limit 2 treatments per cutting. Armyworm only.
  • methoxyfenozide (Intrepid 2F) at 0.06 to 0.16 lb ai/a. PHI 7 days for hay; 0 days for forage; livestock can enter and graze on treated area immediately after application. REI 4 hr. Do not exceed 0.5 lb ai/a per year. Do not make more than one application per cutting.
  • pyrethrins (Pyganic Crop Protection EC 5.0) at 0.032 to 0.05 lb/a. PHI 12 hr. REI 12 hr. OMRI listed for organic use. Armyworm only.
  • pyrethrins/piperonyl butoxide (EverGreen EC) at 0.008 to 0.050 lb ai/a. Do not make more than 10 applications per growing season. Do not re-apply within 3 days of last application. REI 12 hr.
  • spinosad (Entrust SC) at 0.031 to 0.062 lb ai/a PHI 0 days forage; 3 days hay and fodder. REI 4 hr. Limit 6 treatments per year. Do not exceed 0.186 lb ai/a per season. Do not apply more than three times in a 21-day period. Do not graze cattle until spray has dried. Some formulations are OMRI-listed for organic use.
  • zeta-cypermethrin (Mustang) at 0.028 to 0.05 lb ai/a. PHI 3 days for cutting and grazing; 7 days for seed. REI 12 hr. Do not apply more than 0.05 lb ai per cutting or 0.125 lb ai per season. Retreatment interval 7 days.

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