Asian citrus psyllid and huanglongbing disease
UC ANR Research at a Glance - Fighting to Protect California Citrus
![Asian citrus psyllid and huanglongbing disease are serious threats to the California citrus industry. Asian citrus psyllid and huanglongbing disease are serious threats to the California citrus industry.](http://ucanr.edu/sites/ucanr/files/158340display.jpg)
UC ANR is working to . . .
. . . educate communities about this serious threat to California’s citrus
![“It is critical that we educate and engage the public about how best to protect California citrus from this deadly threat.” —Beth Grafton-Cardwell, UCCE specialist in the Department of Entomology at UC Riverside “It is critical that we educate and engage the public about how best to protect California citrus from this deadly threat.” —Beth Grafton-Cardwell, UCCE specialist in the Department of Entomology at UC Riverside](http://ucanr.edu/sites/ucanr/files/158326display.jpg)
. . . keep infected plants out of California
ANR scientists at UC Riverside are developing a legal source of popular, non-citrus plants that host ACP, such as bael tree and curry leaf, plants from India used in cuisine and traditional medicine. This program will provide clients with clean plants to reduce the incentive for smuggling plants and plant material into California that potentially harbor the insect and/or its disease.
. . . protect plants in nurseries
![“UC ANR research is vital to defeating this major threat to California’s $2.1 billion industry. We simple cannot afford to lose this fight.” - Earl Rutz, “UC ANR research is vital to defeating this major threat to California’s $2.1 billion industry. We simple cannot afford to lose this fight.” - Earl Rutz,](http://ucanr.edu/sites/ucanr/files/155707display.jpg)
. . . catch the insect and disease before it spreads
![“If there is an ACP or HLB find, we can use the database to assess the risk of spread into urban areas and commercial citrus.” —Kris Lynn-Patterson, GIS coordinator leading the project “If there is an ACP or HLB find, we can use the database to assess the risk of spread into urban areas and commercial citrus.” —Kris Lynn-Patterson, GIS coordinator leading the project](http://ucanr.edu/sites/ucanr/files/158341display.jpg)
. . . build a better insect trap
ANR scientists at UC Riverside are testing olfactory neurons in the insect’s antennae to screen hundreds of chemicals as possible attractants and/or repellents. This could lead to better traps and/or repellents to protect citrus trees.
. . . introduce natural enemies to kill the insect
ANR researchers at UC Riverside are developing methods for mass rearing two insect natural enemies that theycollected from Pakistan. These two tiny wasps lay eggs inside bug nymphs; the hatching larvae eat the nymphs, killing them. Releases of one of the wasps are under way in urban areas of Southern California.
. . . detect the disease sooner
![“Once we understand the metabolic changes induced by the pathogen, the information may help with development of earlier detection methods and new treatments,” said Carolyn Slupsky, UC Davis assistant professor in the Department of Nutrition and Department of Food Science and Technology. “Once we understand the metabolic changes induced by the pathogen, the information may help with development of earlier detection methods and new treatments,” said Carolyn Slupsky, UC Davis assistant professor in the Department of Nutrition and Department of Food Science and Technology.](http://ucanr.edu/sites/ucanr/files/158338display.jpg)
Scientists at UC Riverside are working to identify the disease-induced molecules that will indicate whether a citrus tree is infected with the disease long before the plant expresses symptoms.
Meanwhile, other UC Riverside scientists believe that pathogen-specific proteins in a citrus plant’s phloem tissue could be a more reliable disease detection tool than the pathogen itself. The method was used successfully with citrus stubborn disease.
. . . develop methods to protect organic citrus
Scientists with UC Cooperative Extension are exploring treatment options for homeowners and farmers who do not use synthetic pesticides on their citrus. The current recommendation for organic growers is to spray a low rate of oil on trees at 14-day intervals. At Lindcove Research and Extension Center, the effects of this treatment on citrus health productivity and fruit quality are being evaluated. A Cooperative Extension advisor is screening additional organic insecticides on a greenhouse colony of ACP to find products that may have greater persistence and efficacy against the insect.
. . . find cost-effective solutions for pest and disease management
![A multi-grafted tree in a Hacienda Heights backyard was the first in California to be found infected with HLB. A multi-grafted tree in a Hacienda Heights backyard was the first in California to be found infected with HLB.](http://ucanr.edu/sites/ucanr/files/158339display.jpg)
. . . find long-term solutions to this deadly insect and disease
UC Ag Experiment Station scientists in Davis are using bioengineering to develop rootstocks that are resistant to HLB and other diseases, helping citrus evolve into a plant that is immune to the disease caused by ACP.
Meanwhile, researchers in Florida have found trifoliate orange rootstock to have some natural resistance to the disease. Now they are working with UC ANR scientists to transfer this resistance to edible citrus varieties.
Learn more about UC ANR efforts to address the problem:
- Ensure that citrus trees start out HLB-free.
- Reduce ACP populations.
- Detect HLB-infected trees so they can be removed as quickly as possible.
- Find a long-term cure.
- Engage the public and enlist their help in fighting Asian citrus psyllid and huanglongbing disease.
Download the information on UC research and outreach in PDF format.