The LA Times had a cover story last Thursday on California’s first recorded case of huanglongbing aka “yellow dragon disease”. Since this threatens all our citrus trees and was discovered close to us in the San Gabriel Valley, we all need to be aware of what to look for.
The Asian Citrus Psyllid (ACP) that spreads the disease has been in California since 2008, but without the concomitant presence of the bacteria it was no special danger. Now, however, it is.
This is a link to the article: http://www.latimes.com/news/local/la-me-citrus-disease-20120414,0,2096027.story.
This is an Asian Citrus Psyllid:
This is an easy way to check trees for the psyllids: hold a stiff laminated piece of white paper (or a white or clear clipboard… it needs to be slippery so the psyllids can’t move off it) about a foot beneath a branch. Hit the branch three times with your hand or piece of PCV pipe. Both beneficials and bad guys will fall off but none will be hurt. You should really do this to all your citrus trees.