While the Asian citrus psyllid and huanglongbing (HLB), the disease the psyllid vectors, has been in the Golden State for more than 15 years, California Citrus Mutual President and CEO Casey Creamer says the state has done well managing the pest, which could be a major threat to the state’s commercial citrus growers.
“We’ve done a good job of keeping it out of commercial citrus, I think way better than anybody predicted at the time,” Creamer says. “We also have seen expanding HLB disease in residential backyard trees in Southern California. So, there’s been a lot of effort, a lot of work, a lot of money, a lot of science goes into all of this to protect the industry.”
And protecting the industry is paramount, Creamer says, as HLB causes significant changes in the appearance and flavor of the fruit of infected trees.
“When you talk about California and the fresh market, HLB can create sort of misshapen fruit and change the taste profile,” he says. “If we had rampant HLB in California, it would drastically affect the industry, and no longer would you have the healthy, fresh citrus that we have today.”
Creamer says an HLB find in Ventura County in 2024 threatened a significant portion of commercial citrus. He says it also impacts growers that fall under that quarantine, because they then must undertake significant steps to move fruit to prevent the spread of HLB.
“Any time a commercial operation gets put into one of these quarantine areas, it is additional mitigations that have got to be applied to those growers at additional costs,” he says. “And depending on where the ranch is located and where you’re packing the fruit, there’s just an additional logistic constraint as well. Generally, HLB is not in commercial groves, but we remain vigilant.”
Creamer says this vigilance comes in the form of a trapping network throughout the state in commercial groves and residential areas, and inspectors monitor those traps frequently. If an Asian citrus psyllid is found in a trap, a lab analyzes the specimen for HLB.
“If something comes back positive, or we find traps especially near or find the psyllid near commercial groves, additional actions would be taken to ensure that any psyllids that may potentially be in that area are controlled and maintained,” he says.
Growers practice integrated pest management and scout the commercial groves, too. Creamer says inspectors also sample trees following any positive finds in traps to test for the presence of HLB, and any trees found positive with HLB are removed.
In addition, growers cover all loads of citrus to prevent the spread of the psyllid, and packinghouses also trap and scout for psyllids.
“There’s extensive mitigations to try to avoid the movement, because the psyllid doesn’t fly very far,” Creamer says. “So, if you can prevent the movement or control the movement, that significantly lessens the ability of the citrus to spread the disease from an infected area of the state that is currently in Southern California, residential backyards, to the major production areas in California.”
But residential citrus remains the highest risk for the spread of the Asian citrus psyllid and HLB. Creamer says a program that focuses on residents, led by the citrus industry in the state as well as the California Department of Food and Agriculture, has been essential to the prevention of the spread of the Asian citrus psyllid.
“The program has done an extensive job in educating homeowners about the importance of the citrus industry, how important it is to take care of your citrus tree, how to report if you suspect it may have a disease, how to work with the program when we do trapping and surveying, and when we find diseased trees, how important it is to remove that tree,” he says. “There has been an extensive partnership and extensive cooperation, and it has been a huge success.”
But he says it’s also the industry’s greatest weakness because of residential citrus trees that are so prominent in Southern California.
“There’s so many people that love citrus in Southern California,” Creamer says. “It’s part of the culture of Southern California, and people want to continue to be able to grow it in their backyards and front yards. It’s a huge challenge, and it’s going to continue to be a huge challenge moving forward. We just appreciate that partnership and hope that we can continue it and improve on it as we move forward to, not only protect the industry, but protect the cultural history of the California citrus industry.”
