Agriculture: Citrus Pest Management Guidelines

California Orangedog

  • Papilio zelicaon
  • Description of the Pest

    (View Caterpillar ID Key) (PDF)

    The California orangedog, or black anise swallowtail, is a native butterfly that feeds on both perennial anise (sweet fennel) and citrus. During its development, the caterpillar changes from a mottled brown to a whitish green and bright green with yellow and black spots on each segment. Mature larvae are about 1.5 inch (3.7 cm) long. When disturbed, all larval stages stick out orange-colored scent glands and give off a strong odor.


    Orangedog caterpillars feed on tender citrus leaves, occasionally defoliating young trees but rarely causing economic damage in mature orchards.


    Management of California orangedog may occasionally be necessary in young orchards. Use selective (i.e., those that are toxic only to a narrow group of insects) insecticides to conserve natural enemies.

    Biological Control

    Parasites are often highly effective in controlling California orangedog, especially the wasp Hyposoter sp.

    Cultural Control

    California orangedog prefers sweet fennel, which may be interplanted as a trap crop in strips with citrus and mowed regularly after the egg-laying peak in each generation.

    Organically Acceptable Methods

    Use biological and cultural controls and sprays of Bacillus thuringiensis on organically managed citrus.

    Monitoring and Treatment Decisions

    If a pesticide application is needed for infestations of California orangedog on immature trees, Bacillus thuringiensis generally provides sufficient control.

    Common name Amount to use REI‡ PHI‡
    (Example trade name) (type of coverage)** (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.
    (various) Label rates (OC) 4 0
    RANGE OF ACTIVITY: Pests: narrow (caterpillars); Natural enemies: none
    PERSISTENCE: Pests: short; Natural enemies: none
    COMMENTS: Can be used during bloom. Timing is important because of short residual period. Use lower rates for younger worms or smaller trees. Apply only during warm dry weather to control young, actively feeding worms. Use reduced wind velocity and drive 3 mph.
    (Prokil Cryolite 96) 8–20 lb/acre (OC) 12 15
    (Kryocide) 8–20 lb/acre (OC) 12 15
    RANGE OF ACTIVITY: Pests: intermediate (foliage feeders such as worms, katydids, and Fuller rose beetle); Natural enemies: few, if any
    PERSISTENCE: Pests: long, unless washed off by rain; Natural enemies: none to short
    COMMENTS: Check label for variety. Use higher rate for larger trees. Slow-acting stomach poison that may take several days of warm weather to kill worms. Use reduced wind velocity and a speed of 3 mph. Use of Prokil Cryolite 96 allowed under a supplemental label.
    (Intrepid 2F) 8–16 fl oz/acre 4 1
    RANGE OF ACTIVITY: Pests: narrow (caterpillars); Natural enemies: few
    PERSISTENCE: Pests: intermediate; Natural enemies: short
    ** OC - Outside coverage uses 100 to 250 gal water/acre.
    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.
    # Acceptable for use on organically grown produce.
    1 Rotate chemicals with a different mode-of-action group number, and do not use 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; chemicals with a 1B group number should be alternated with chemicals that have a group number other than 1B. Mode-of-action group numbers (un = unknown or uncertain mode of action) are assigned by IRAC (Insecticide Resistance Action Committee).
    Text Updated: 02/17
    Treatment Table Updated: 02/17