From KBAK and KBFX Eyewitness News, Bakersfield:
Science Non Fiction: Parasitic Wasps Releases to Go After Psyllids
By Christine Bedell
Thousands of tiny, parasitic wasps originating from Pakistan are being released in residential areas throughout Bakersfield in the latest effort to protect Kern citrus from the dangerous and stubbornly reappearing Asian citrus psyllid.
State and local agricultural officials began spreading the Tamarixia radiata around citrus trees in 23 locations Tuesday in an experiment that’s been performed in Southern California to combat the psyllid and an incurable, deadly plant disease it transmits, Huanglongbing.
Ag experts have seen an alarming increase in the number of Asian citrus psyllids in Kern County over the last year in both residential areas and packing houses, prompting them to take the new tack. Fortunately, they have not detected Huanglongbing in Kern, where citrus was the No. 4 crop in terms of value in 2014, worth $892.9 million.
“It’s been very successfully established in Southern California,” Victoria Hornbaker, citrus program manager for the California Department of Food and Agriculture, said of the Tamarixia radiata release program. “We want to see if we can get some success in Kern County.”
The Tamarixia radiata is a natural predator of the Asian citrus psyllid but doesn’t harm other pests. Crews are releasing 200 to 600 of them per location, depending on the area’s psyllid risk. They’re likely to do releases monthly; it will take about a year to determine if the work is successful.
Partners in the endeavor include the Kern County Department of Agriculture and Measurement Standards, California Department of Food and Agriculture, U.S. Department of Agriculture and University of California.
Huanglongbing was found in Hacienda Heights in 2012; there have since been 26 additional finds on residential trees in Los Angeles County. Infected trees die and must be removed.
The worry is that the Asian citrus psyllid could spread the disease to healthy trees throughout the state, including the Central Valley, where much of California’s commercial citrus is produced.
Backyard citrus growers are at risk, too, as there’s as much residential as commercial citrus growing in California. It’s estimated citrus is grown at 70 percent of residences in Bakersfield.
The spike in psyllid detection locally does not mean eradication efforts are failing, said Darin Heard, supervising agricultural biologist with the county ag department.
It’s just that the psyllid keeps getting transported to Kern from outside the area, he said. People unwittingly bring the pest here via citrus and/or uncleaned agricultural equipment.
Experts have also begun to detect nymph psyllids in Kern, meaning there’s breeding going on, Heard said.
Officials stressed Central Valley growers and residents have been very helpful in the psyllid fight and they appreciate it.
“A lot of eyes are out there looking for this bug,” Hornbaker said.