- Author: Chris M. Webb
The Asian citrus psyllid (ACP) continues to be found in several California counties. New finds are being made on a weekly basis. Ventura County and others with this pest remain in quarantine, which means fruit and plant material movement is restricted in these counties.
UC’s Elizabeth Grafton-Cardwell has recently provided an update on LA’s urban infestation. The update can be found on UC ANR’s Citrus Bugs Blog.
UC researchers have begun releasing Tamarixia radiate in Riverside County and soon into Los Angeles county. Tamarixia radiate is a tiny wasp and a natural enemy of ACP. Details of the release and the program can be found on the ANR News Blog.
Invasive species cause billions of dollars’ worth of damage annually. As with all invasive species, it is primarily people who are responsible for ACP’s movement. Please do what you can to avoid moving these pests.

- Author: Chris M. Webb
On March 21, 2011 the Ventura County ACP-HLB Task Force sponsored a workshop for citrus growers, nursery operators and pest control advisors.
The presentations from the workshop have been archived on our website with sound. Titles and presenters are as follows:
- ACP update and overview of treatment protocol for commercial orchards: Beth Grafton-Cardwell, IPM Specialist and Research Entomologist, University of California’s Kearney Agricultural Center, and Director of Lindcove Research and Extension Center.
- Research update regarding biocontrol of psyllids: Raju Pandey, UC Riverside Department of Entomology.
- Research update regarding chemical control of psyllids: Joseph Morse, UC Riverside Department of Entomology.
Please click here to access the workshop recordings.

- Author: Chris M. Webb
The Asian Citrus Psyllid (ACP) has recently received a lot of media coverage and for good reason. ACP carries the deadly Huanglongbing (HLB) bacteria, the most serious citrus plant disease in the world. The disease kills all varieties of citrus trees and related plants such as orange jasmine and Indian curry leaves. The psyllid, about the size of an aphid, does not always carry HLB, but once an ACP feeds on an infected plant the psyllid will carry the disease for life to each plant on which it feeds.
What is particularly troubling about this pest-disease complex is that it can take years for the infected citrus trees to die; therefore, owners of the infected trees may not be aware they have the disease. While fruit from infected trees can be bitter, misshapen, and inedible, the tree stays up and can continue to be fed upon by psyllids, causing HLB to spread further.
People and our global economy are moving this insect. ACP has spread through Asia, parts of the Middle East, South and Central America. It has been found in Mexico, Hawaii, Texas, Louisiana, Georgia, Alabama, South Carolina, Florida and arrived in southern California in 2008. None of the ACP’s found in California have tested positive for HLB. However, it is highly likely that HLB-infected plants, brought from infected areas, are already here.
What can you do? Do not bring in plant materials from areas known to be infected with ACP. If our area becomes infected, do not move any plant materials out of our area. Purchase only certified pest- and disease-free trees from a reputable nursery. Stay informed. Check your trees regularly for signs of ACP. Report suspected ACP and/or HLB to the County Agricultural Commissioner or the California Department of Food and Agriculture (CDFA).
- Author: Chris M. Webb
Today we share a recent press release. The Ventura County Master Gardeners are working hard to educate home gardeners about the Asian citrus psyllid and the deadly bacterial disease it carries.
Residents of Ventura County are asked to be on the lookout for a tiny insect that could wipe out California’s citrus industry — and with it, every lemon, lime, orange, grapefruit and mandarin tree in every urban and suburban yard.
This tiny insect, known as the Asian citrus psyllid (SIL-lid), carries a bacterial disease that is harmless to humans but inevitably fatal to all varieties of citrus. There is no treatment or cure. The disease has already destroyed millions of trees in citrus-producing regions around the world, including Florida.
The pest has been found in San Diego, Imperial, Orange and Los Angeles counties, and is expected to reach Ventura County this year. The disease is not far behind — infected trees have been found in western Mexico, and the disease is moving steadily closer to California.
The only way to stop this plague is to quickly find and kill the insect pest whenever it reaches a new area. If you have citrus trees in your yard, inspect them often. The insect feeds on the new leaves and stems of all citrus varieties. Twisted, stunted new growth is a sign your tree may be infested by the psyllid, which looks like a small, brown grain of rice. You may also notice the tiny nymphs feeding on tender young growth. Look for sticky white secretions, like honeydew, or sooty mold clinging to the leaves.
If you think you have spotted this invasive pest in your trees, report the sighting immediately by calling 1-800-491-1899.
For more information about the pest and the disease it carries, call the Ventura County ACP-HLB Task Force at 805-535-8641, or visit their Facebook page.
- Author: Chris M. Webb
A team of scientists from the Agricultural Research Service of the U.S. Department of Agriculture and the University of Florida’s Indian River Research and Education Center are studying the use of periwinkle (Catharanthus roseus) to fight Huanglongbing (HLB). HLB is a bacterial disease that threatens citrus crops worldwide. The bacteria is spread by the Asian Citrus Psyllid.
The scientists infect the periwinkle plants with HLB and then run experiments on the diseased plants in an effort to find a way to return the plants to good health. They have used nutrient and soil treatments to regenerate infected plants and have placed cuttings in chemical compounds to search for HLB treatments.
Further information on this research and more can be found in the May 2010 edition of the Topics in Subtropics Newsletter on our website.

Yellowing leaves is one symptom of HLB

Periwinkle shows promise for solutions
to problems caused by HLB