- Author: Cris L. Johnson
Once a tree has been infected by the psyllid that carries and transfers the huanglongbing (HLB) bacteria to the tree there has been no alternative but to quarantine the infected area and destroy the tree. To complicate the issue further, the disease can lie dormant and be difficult to detect as the infection spreads from tree to tree.
Efforts to control the psyllid through pesticides have been ineffective and while quarantines have helped raise awareness and slowed some of the spread, a viable weapon to combat this invasive pest has been unavailable until recently.
Mark Hoddle, director at the Center for Invasive Species Research at UC Riverside, has been experimenting with a tiny parasitic wasp, Tamarixia radiata, that feeds on and kills the psyllid. After a series of tightly controlled and successful tests, the wasps have been released on infected sites and have been effective in reducing the psyllid population. There is no danger to pets or humans and the release program has been approved by the Department of Agriculture.
To learn more about this effort, please see the UC Riverside Newsroom article.
- Author: Cris L. Johnson
The latest issue has recently been posted on our website and features articles on:
Cultural Practices to Reduce Pest and Disease in Avocado and Citrus. This article by UC Ventura County Cooperative Extension advisor Dr. Ben Faber provides guidelines for practices from selection to maintenance that can mitigate disease and pests in trees.
Polyphagous Shot Hole Borer in California. UC Cooperative Extension cross-county advisor Dr. Sabrina Drill discusses this pest and it's effects on Southern Californian trees.
Electronic "sniffer" for Detecting HLB. Dr. Faber also reports on a new device that can detect Huanglongbing (HBL) disease in trees. Learn more about how it works and the advantage it could provide in preventing HLB spread through early detection.
Important Information Sources Related to Fire Management and Protection. The fire season is still on us and this list of online and publshed resources provides useful information for property owners.
Bee Kill in Oregon - A reminder of pesticide use. The State of Oregon has issued a moratorium on an aphid control pesticide after its use killed a large amount of bumble bees. Read more about following the proper guidelines on pesticide use here.
Read the full articles from this newsletter or check out other issues of Topics in Subtropics here.
- Author: Cris L. Johnson
Firewood borne diseases and pests can cause devastating damage to trees and huge financial losses to growers and the agricultural community. The simple yet important act of keeping firewood purchases local and not transporting to public areas can help prevent invasive pests such as the Asian Citrus Psyllid (ACP), gold spotted oak borer, emerald ash borer and others from gaining a foothold in your community.
For more useful information about this important effort, visit the California Firewood Task Force website. The Farm Bureau Pest Issues webpage has a list of invasive pests and diseases that could threaten Ventura County. Also check out a special presentation on ACP at the UCCE ACP Workshop webpage.
- 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
There have been two earlier posting on this blog about the Asian Citrus Psyllid (ACP)and the potential crippling impact for citrus in California caused by the Huanglongbing vector (aka citrus greening disease) this insect carries. Please read the Introduction to the Asian Citrus Psyllid and Asian Citrus Psyllid: Lessons from Florida for additional information about this pest.
We are entering the time of year in which the ACP becomes most active. Make sure to check your trees regularly for signs of this insect. The Introduction to the Asian Citrus Psyllid post provides detailed photos and descriptions of how to determine if this species is on your trees. If you see this psyllid, call the California Department of Food and Agriculture at 1-800-491-1899 right away.
I recently asked Ventura County UCCE Farm Advisor Ben Faber what I should share about the ACP. He said to remind people how important it is to make sure to declare plant items when crossing the border. It is people who are spreading this around.
Recently UC Agriculture and Natural Resources’ News and Information group released a video demonstrating for the general public how to detect Asian Citrus psyllids on their garden trees. The video is available at:
http://news.ucanr.org/newsstorymain.cfm?story=1233
In addition, our office has a supply of bookmarks that contain photos and instructions for identifying both ACP and trees struck by Huanglongbing. They are available in both English and Spanish. Please contact our office if you would like some.
ACP infestation
ACP feeding damage
Distorted leaves from ACP
