California farmers find themselves in a pitched battle against a little insect with a taste for citrus. The Asian citrus psyllid is having such a grand ‘ole time sucking juice from plants across Southern California, it’s moving north into the state’s agriculture heartland. This week, a quarantine goes into effect in Tulare County, where state agriculture officials recently identified the third psyllid found in the county this year.
Entomologist Mark Hoddle of UC Riverside told the California Report it’s not so much the wee psyllid that worries farmers as a bacterial disease that often travels inside the bug: huanlongbing (also known as “citrus greening”).
The Asian citrus psyllid essentially acts “like a flying syringe,” Hoddle says. It injects bacteria into each citrus tree it feeds on. “Once infected, there is no cure. It is a 5-8 year death sentence for the tree!” The disease has hit Florida citrus production hard since its discovery there in 2005.
Despite efforts to get the word out to citizens with citrus trees in their backyards, Californians can unwittingly move trees and fruit from infested to un-infested areas. That, and there are so many citrus trees in California backyards, it’s easy for the psyllid to hopscotch from one property to another. “As you can imagine,” Hoddle says, “it’s very difficult to police.”
Farmers have been applying topical pesticides to protect against infestation. They also wash fruit ahead of shipping it to market, so it’s not something consumers have to worry about – yet.
Some folks think the larger impact will be on nurseries that serve farms and civilian gardeners – and organic farmers. What happens if it spreads over the entire Central Valley, the “nightmare scenario” as Hoddle calls it? Organic pesticides now commercially available are not that effective.
Hoddle has personally (with permission) imported a natural predator to the psyllid: the Punjabi wasp. It has a gruesome habit of injecting its eggs into the psyllid nymph for the future larvae to feast on. After releasing about 25,000 wasps into Southern California, Hoddle says the parasites have spread up to three miles beyond their initial release sites. That would indicate there’s plenty of psyllids for the wasps to attack.
After the initial feed fest, Hoddle is hopeful both populations will decline. “The safety testing clearly demonstrated that the only food the psyllid parasite is interested in attacking is the Asian citrus psyllid.”
Look outside. Are there little critters waving their fannies at you from your citrus trees?
It’s time to call the California Department of Food & Agriculture at 800-491-1899.