All of Sacramento County is under a plant pest quarantine after the Asian citrus psyllid bug was found in the Lemon Hill area of south Sacramento, the California Department of Food and Agriculture said Thursday.
The psyllid is a species of bug that can carry citrus greening disease, or huanglongbing, which poses a threat to all citrus and related plants and for which there is no cure once infected. The bugs transmit the bacterial disease to healthy trees after feeding on infected plant tissue, the agency’s Plant Health & Pest Prevention Services department said.
CDFA’s news release calls the vector outbreak a “grave concern,” prompting a quarantine after just one reported psyllid bug was detected in the county.
The quarantine “prohibits the movement of citrus and curry leaf tree nursery stock and all plant parts except fruit out of the quarantine area,” the news release says.
Trees with the disease, commonly called HLB, will produce “bitter, misshapen fruit” and eventually die, according to Thursday’s news release.
With citrus plant owners advised to be diligent, Sacramento County Agricultural Commissioner Juli Jensen went into further detail about signs of psyllid presence.
“This is a very, very tiny insect, but it does have a waxy discharge that you might be able to notice in the new growth of the citrus,” Jensen said.
But the Asian citrus psyllid, or ACP, doesn’t look like tree sap, she said.
“It’s kind of like a whitish, waxy, little string.”
Jensen said there have been “signs of ACP” in nearby Yolo and Placer counties recently.
The state and Sacramento County will work together to put 200 delimitation square traps in the immediate area of the Lemon Hill find – 50 per square mile across 4 square miles, Jensen said.
“That’s a pretty good density for trapping. They’re really trying to delimit it down and find out how small an area is actually affected. ... We’re currently hoping the residents will be cooperative so we can get this under control while it’s still in a very small area.”
Jensen said county pesticide staff will try to treat all citrus plants within a 50-meter radius of the find site, which she said includes about 50 small trees. They will also notify all residents within 150 meters of where the psyllid was found. The trapping will involve fairly common pesticides, she said.
The entire county is under the travel quarantine, and Jensen said anyone buying citrus plants in a psyllid-affected county, like Sacramento, should not plant them in an unaffected county.
Gardeners also shouldn’t move citrus fruits from an affected area into an unaffected area without removing stems and leaves first, as well as giving them a thorough wash.
Sarah Bowles, a spokeswoman for the state- and industry-backed Citrus Pest & Disease Prevention Program, said the psyllid has been observed and more than 1,100 HLB cases have been detected in Southern California since their first appearance there in 2012. Cases have been documented in Los Angeles, Orange and Riverside counties.
“HLB has not yet been detected in Northern California,” Bowles said. “However, the pest that spreads the disease has been found in Sacramento.”
The disease does not directly affect human health.
While the Asian psyllid has not been seen in Sacramento, Jensen said the glassy-winged sharpshooter is another pest that has posed a threat to citrus plants in the region.
The sharpshooters have been spotted twice in Sacramento, and they carry Pierce’s disease. Jensen said the county was able to eradicate the vector on each of those occasions, preventing outbreaks.
Sacramento County is one of over two dozen counties in the state included in CDFA’s Bulk Citrus Regional Quarantine Zone No. 1, which is defined as areas away from the Mexico border, where HLB has not been detected and where no large, contiguous citrus growing regions exist.
Sacramento County residents are advised to inspect trees for psyllids whenever watering or tending trees, as well as to only plant trees acquired from reputable, licensed local nurseries.
Anyone who thinks they have discovered psyllids or observed symptoms of citrus greening disease on their plants should call CDFA’s pest hotline at 800-491-1899 or the Sacramento County agricultural commissioner at 916-875-6603.