Agriculture: Artichoke Pest Management Guidelines

Loopers

  • Alfalfa looper: Autographa californica
  • Cabbage looper: Trichoplusia ni
  • Description of the Pest

    Loopers arch their backs as they crawl. Cabbage loopers usually have a narrow, white stripe along each side and several narrow lines down the back. Eggs are dome-shaped and laid on the undersurfaces of older leaves. Adult moths have brown, mottled forewings marked in the center with a small, silver figure-8.

    Damage

    Young larvae feed primarily on the undersides of lower leaves, skeletonizing them. High populations can damage seedlings severely enough to kill them or slow growth enough to inhibit uniform maturing of the crop. Older larvae may burrow into the head from the top.

    Management

    Primarily an early-season pest in inland desert growing area, where loopers are managed with treatments.

    Biological Control

    Loopers have many natural enemies that often keep populations below economic thresholds. Maximize the use of these natural enemies by limiting treatments, especially between thinning and heading.

    Organically Acceptable Methods

    Biological control and sprays of Bacillus thuringiensis are acceptable for use on organically certified crops.

    Monitoring and Management Decisions

    Look for signs of looper feeding: plants with holes in outer leaves, feces, caterpillars feeding on edge of hole. Check fields twice a week once seedlings emerge.

    Treat seedlings or small plants if populations of medium-sized to large loopers are large enough to stunt growth. Treat well established plants only if you find an average of more than one-half larvae per plant. For cabbage looper control, the best time to apply insecticide is in the afternoon.

    Common name Amount per acre REI‡ PHI‡
    (Example trade name) (hours) (days)
    Not all registered pesticides are listed. The following are ranked with the pesticides having the greatest IPM value listed first—the most effective and least harmful to natural enemies, honey bees, and the environment are at the top of the table. When choosing a pesticide, consider information relating to air and water quality, resistance management, and the pesticide's properties and application timing. Always read the label of the product being used.
     
    A. CHLORANTRANILIPROLE
      (Coragen) 3.5–7.5 fl oz 4 3
      MODE-OF-ACTION GROUP NUMBER1: 28
      COMMENTS: Do not make more than 4 applications/acre per crop and do not apply more than 15.4 fl oz Coragen (0.2 lbs a.i.)/acre per crop.
       
    B. SPINETORAM
      (Radiant SC) 6–8 fl oz 4 2
      MODE-OF-ACTION GROUP NUMBER1: 5
      COMMENTS: For resistance management, do not make more than two consecutive applications of group 5 insecticides.
      ...OR...
      SPINOSAD
      (Entrust SC)# 4.5–10 fl oz 4 2
      MODE-OF-ACTION GROUP NUMBER1: 5
      COMMENTS: For resistance management, do not make more than two consecutive applications of group 5 insecticides.
       
    C. BACILLUS THURINGIENSIS ssp. AIZAWAI
      (Agree WG)# 1–2 lb 4 0
      MODE-OF-ACTION GROUP NUMBER1: 11A
      COMMENTS: Apply when loopers are small. Not harmful to natural enemies. Check with organic certifier to determine which products are organically acceptable.
       
    D. DIFLUBENZURON
      (Dimilin 2L) 8–16 fl oz 12 1
      MODE-OF-ACTION GROUP NUMBER1: 15
      COMMENTS: Use allowed under 24(c) regulation (EPA SLN No. CA-970009).
    Restricted entry interval (REI) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (PHI) is the number of days from treatment to harvest. In some cases, the REI exceeds the PHI. The longer of two intervals is the minimum time that must elapse before harvest.
    1 Rotate insecticides with a different mode-of-action group number, and do not use the products with the same mode-of-action group number more than twice per season to help prevent the development of resistance. For example, the organophosphates have a group number of 1B; insecticides with a 1B group number should be alternated with insecticides that have a group number other than 1B. Mode-of-action group numbers are assigned by IRAC (Insecticide Resistance Action Committee).
    # Acceptable for use on organically grown produce.
    Text Updated: 01/07
    Treatment Table Updated: 02/20