If there is no Pest Note covering the problem you have identified, it is possible that you have an exotic pest. A new exotic pest appears in California every 60 days. Such a species may not be a problem in its native habitat because other organisms have evolved to feed on them, keeping their populations under natural control. These pests usually arrive without their natural enemies. Without natural enemies to feed on them and keep them under control, they can rapidly become a problem, until researchers and regulatory agencies learn how to control them.
If you find an unusual pest in your garden, visit the Exotic Pest Index. This website contains information on recently introduced pests for which there is no Pest Note. You can find out what progress has been made on managing the pest.