2012-08-24 / Front Page
Pest poses danger to citrus crops
The Asian citrus psyllid—an insect that can carry Huanglongbing, a disease which kills citrus trees—has been found in Southern California and may threaten Ventura County’s $200-million citrus industry.
The disease, which kills citrus trees and has no cure, first appeared in the state in April when the California Department of Food and Agriculture found a contaminated tree in Hacienda Heights, a city about 20 miles east of downtown Los Angeles.
The discovery set off a state- wide program of ongoing testing in an effort to contain the psyllid and stop the spread of the disease.
The insect has so far been spotted in Los Angeles and Riverside counties—as well as areas farther south—but experts say the bug could spread elsewhere.
The Acorn spoke with John Krist, the chief executive officer of the Farm Bureau of Ventura County, to discuss the psyllid and learn what residents can do to combat the disease-carrying pest.
Have there been any new detections of Huanglongbing in California since April?
There has still been only that single detection in Hacienda Heights. The bug or transmitter of the disease, however, is a population that continues to increase in Los Angeles and Riverside counties, which means we’re not that far away. We haven’t had any detection (of the bug) in Ventura County since March, but we’re still looking for it.
What is the Southern California region doing to keep the Asian citrus psyllid population from spreading?
We’re seeing promising signs from a bio control program in Los Angeles. A couple years ago, researchers from (UC Riverside) went to Pakistan and were looking for natural predators that feed on the bug.
They found wasps, and the primary thing the wasps do are find larval bugs and stab them and lay eggs underneath. The wasp larva eats the (citrus psyllid) bug and cuts a circular hole and comes out of the top of it. It’s like a scene from “Alien.”
The researchers did testing for two years and released the wasps in the Los Angeles area, and the wasps are preying on the (citrus psyllids). That’s a good sign.
Will the parasitic wasps wipe out the Asian citrus psyllid population?
If we could release millions of (the wasps) it could reduce the population, but it’s still not known. We don’t know if the wasps will reproduce successfully or how happy they will be in our climate. At best (the wasps) will only reduce the population by 20 to 30 percent, but it will never eradicate the psyllid population.
Does that mean we’ll live with the bug forever now that it’s here?
The bug all by itself is not that big a deal, but wherever the bug has gone in the world the disease has followed it. Once the bug population gets established like in Texas or Florida, they’re never going to get rid of it. They breed quickly and they’re mobile.
With Santa Ana wind season coming it’s entirely possible for the critters to be picked up by the winds and spread over the course of a day. The strategy right now is to confine the big population in Los Angeles, and the (agencies) are being very aggressive. Any detection outside of that boundary they established results in aggressive chemical treatment.
If the population may never go away, what does that mean for citrus growers in Ventura County?
We know the disease is out there so we need to “selfishly” make sure Ventura County doesn’t get the bug population. I hope we don’t get to that point because that means we lost the battle. As long as we don’t have the bug to spread (the disease) to our trees, we can survive.
What can Ventura County residents who aren’t farmers do?
In Southern California, more citrus trees are in people’s backyards than there are in orchards. Homeowners should keep an eye on their trees and see if they think things are suspicious. It’s also more important than ever for people to be careful and not be moving plants and fruit.
The “Save Our Citrus” app is one additional tool to help people be active in monitoring their own trees and working together with the state and local agencies to make sure they report suspicious sightings promptly. (The app is available for iPhones. Users can send a photo of trees that appear diseased to the U.S. Department of Agriculture.) The faster we find out about a new infestation, the faster we can wipe it out and keep it from spreading.