How to Manage Pests

UC Pest Management Guidelines


California Orangedog

Scientific Name: Papilio zelicaon

(Reviewed 9/08, updated 9/08, corrected 6/13)

In this Guideline:

Description of the Pest

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 populations of 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

Biological and cultural controls and sprays of Bacillus thuringiensis are organically acceptable methods.

Monitoring and Treatment Decisions

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

Common name Amount to use R.E.I.‡ P.H.I.‡
(example trade name) (type of coverage)** (hours) (days)

Calculate impact of pesticide on air quality
The following materials are listed in order of usefulness in an IPM program, taking into account efficacy and impact on natural enemies and honey bees. When choosing a pesticide, also consider information relating to environmental impact. Not all registered pesticides are listed. Always read label of 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.
** OC - Outside coverage uses 100–250 gal water/acre.
Restricted entry interval (R.E.I.) is the number of hours (unless otherwise noted) from treatment until the treated area can be safely entered without protective clothing. Preharvest interval (P.H.I.) 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). For additional information, see their Web site at



[UC Peer Reviewed]

UC IPM Pest Management Guidelines: Citrus
UC ANR Publication 3441

Insects, Mites, and Snails

  • E. E. Grafton-Cardwell, Entomology, UC Riverside and Kearney Agricultural Center, Parlier
  • J. G. Morse, Entomology, UC Riverside
  • N. V. O'Connell, UC Cooperative Extension, Tulare County
  • P. A. Phillips (emeritus), UC IPM Program, UC Cooperative Extension, Ventura County
  • C. E. Kallsen, UC Cooperative Extension, Kern County
  • D. R. Haviland, UC Cooperative Extension, Kern County
Acknowledgments for contributions to Insect, Mites, and Snails:
  • J. Barcinas, E.S.I., Corona, CA
  • R. Dunn, Badger Farming Co., Exeter, CA
  • J. Gorden, Pest Management Associates, Exeter, CA
  • H. Griffiths, E.S.I., Corona, CA
  • D. Machlitt, Consulting Entomology Services, Moorpark, CA
  • C. Musgrove, retired entomologist, Riverside, CA
  • K. Olsen, S & J Ranch, Pinedale, CA
  • T. Roberts, E.S.I., Corona, CA
  • T. Shea, UC Cooperative Extension, Riverside County
  • J. Stewart, Pest Management Associates, Exeter, CA
  • P. Washburn, Washburn & Sons Citrus Pest Control, Riverside, CA

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