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Posts Tagged: Beth Grafton-Cardwell

Citrus trees sprayed for Asian citrus psyllid in Highland

Beth Grafton-Cardwell.
Backyard citrus trees in Highland, Calif., were sprayed with a pesticide to kill Asian citrus psyllids, reported Jim Steinberg in the San Bernardino Sun. The invasive pests pose a threat because they can carry huanglongbing disease, which is incurable. The California Department of Food and Agriculture is treating trees that have ACP to keep the pest number in California low.

“What they are really doing is buying time until disease resistant trees become available, or there is some treatment for the (huanglongbing) disease,” said Matt Daugherty, a UC Cooperative Extension entomology specialist based at UC Riverside.

The reporter also spoke to Beth Grafton-Cardwell, who is a UCCE entomology specialist at UC Riverside and director of the UC Lindcove Research and Extension Center in Tulare County. She said that it is unlikely huanglongbing was completely wiped out in the Southern California areas where infected trees have been found, even though CDFA destroyed the infected trees.

A tree can be infected for a year before it shows symptoms, she said. 

Grafton-Cardwell asks homeowners to monitor backyard trees for signs of Asian citrus psyllid and report any finds to CDFA or their county agricultural commissioner's office. For more information, see the video below.

Posted on Tuesday, May 3, 2016 at 1:29 PM

Californians are checking new growth on citrus for Asian citrus psyllid

Beth Grafton-Cardwell speaks with ABC30 reporter Dale Yurong, left, and cameraman Sam Gill at the UC Lindcove Research and Extension Center.
The Asian citrus psyllid is public enemy No. 1 at the UC Lindcove Research and Extension Center in Exeter, reported Dale Yurong on ABC30 Action News in Fresno. Yurong visited Lindcove to interview UC Cooperative Extension citrus entomology specialist Beth Grafton-Cardwell, who along with other UC ANR experts is calling on Californians to join the fight against the pest.

"Basically, you just look really closely (at new growth) with any kind of magnifying device you have to see if you can find any insects on there," Grafton-Cardwell said.

If tiny yellow eggs, sesame seed-sized nymphs, or ACP adults are found, take action. Maps, treatment protocols and other information that detail what to do when ACP is present are available at

Since ACP can spread the devastating citrus disease huanglongbing (HLB), controlling the insect population will buy time for researchers working around the world to find a way to grow healthy and delicious citrus fruit in the presence of HLB.

Yurong reported that the disease has been found in a dozen Southern California trees. Grafton-Cardwell figures Valley trees will ultimately get infected.

Dale Yurong poses with a giant mock-up of Asian citrus psyllid.
"HLB is going to come. We fully expect it to come up here because it rides in the bodies of the psyllids," she said.

Reed Fujii of the Stockton Record interviewed Karey Windbiel-Rojas, a UCCE advisor for home and garden integrated pest management, for a story on Asian citrus pysllid.

“It's really important to detect Asian citrus psyllid in backyard trees because one psyllid can carry the disease from tree to tree in a residential landscape,” Windbiel-Rojas. “Citrus growers, they treat all their fields, but home gardeners don't necessarily treat or monitor their backyard trees so it can spread a lot faster in backyards than in managed citrus orchards.”

Stories about the call to check trees this spring for Asian citrus psyllid also appeared in:

View a four-minute video about Asian citrus psyllid here:

Posted on Wednesday, March 9, 2016 at 8:27 AM

Arroyo Grande psyllid has caused a big stir

One sign of potential Asian citrus psyllid infestation is waxy tubules on new growth. (Photo: M.E. Rogers)
The discovery last month of one Asian citrus psyllid on a sticky trap perched in an Arroyo Grande lemon tree has the citrus industry and agricultural commissioner on guard, reported Jono Kinkade in the San Luis Obispo New Times.

They've established a quarantine zone within a five-mile radius of the ACP find and monitoring has been stepped up in the area. Officials are concerned because of the psyllid's ability to spread huanglongbing disease, should the disease make its way into California. (So far, only one backyard tree has been found in California infected with huanglongbing.)

“If you don't have a vector like a psyllid, no big deal, but when you have a vector alive and moving around, then you have a big problem,” said Beth Grafton-Cardwell, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside.

The psyllid is established in some areas of Southern California and has been found in commercial orchards in the San Joaquin Valley, where an eradication plan is underway. In San Luis Obispo County, the main focus is on residential areas.

“It's so tiny that people don't even know they have it,” Grafton-Cardwell said. “It's very difficult to completely eradicate it because 60 percent of California [residences] have a citrus tree in their yard, so it can hop, skip, and jump.”

Comprehensive information about Asian citrus psyllid and huanglongbing disease is available on the UC ACP/HLB Distribution and Management website.

Posted on Thursday, April 10, 2014 at 2:05 PM

Dinuba Asian citrus psyllids the most ever found in the Valley

UC Cooperative Extension's Beth Grafton-Cardwell is one of the state's leading experts on Asian citrus psyllid.
More than 100 Asian citrus psyllids were found on three backyard orange trees east of Dinuba, reported Robert Rodriguez in the Fresno Bee. The homeowner told officials the trees were planted in April 2012 and were acquired from a private party, not a nursery.

"It was incredible," said Fresno County entomologist Gene Hannon. "There were easily a dozen on just one small leaf."

Previous finds in the Valley numbered from one to three on yellow sticky traps in the Tulare County communities of Lindsay, Strathmore and Terra Bella.

Beth Grafton-Cardwell, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside, said the number of psyllids in Dinuba means there is a reproducing population.

"And when that happens, we are off and running to getting an established population in the San Joaquin Valley," she said.

Grafton-Cardwell has worked with a team of UC researchers to provide detailed and scientifically sound guidelines for treating farm- and home-grown citrus infested with Asian citrus psyllid on a new UC Cooperative Extension website,

The website advises farmers and homeowners to regularly conduct visual surveys for Asian citrus psyllid and tap sample (see video) trees in their orchards.


Posted on Thursday, September 12, 2013 at 8:17 AM

Numerous Asian citrus psyllids found in Dinuba

The UC ACP website, which provides information to farmers and home citrus growers at
Numerous Asian citrus psyllids were found in east Dinuba and traced to recently planted backyard orange trees, according to reports in The Business Journal in Fresno and The Fresno Bee.

“This is very surprising and very disappointing,” said Joel Nelsen, president of California Citrus Mutual in Exeter.

This was the third ACP find in Tulare County this year. An Asian citrus psyllid was discovered in Wasco, Kern County, last week.

The Tulare County Agricultural Commissioner, CDFA and USDA are conducting an extensive survey and treatment program in response to the new detection of ACP in Dinuba, according to a press release. Beth Grafton-Cardwell, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside, wrote in her Citrus Bugs Blog that because all stages of the pest were found around the trees in Dinuba they were likely infested when they were planted.

"This situation points out the need to educate everyone that they must never move plant material from ACP-infested areas that are under quarantine to areas such as the San Joaquin Valley where the pest has not yet established," Grafton-Cardwell wrote.

Yesterday Valley Public Radio broadcast a 5-minute overview of Asian citrus psyllid with comments from Grafton-Cardwell.

"This is not just a commercial problem, but a homeowner problem because 60 percent of Californians have at least one citrus tree in their yard," Grafton-Cardwell said.

California Assemblyman Jim Patterson hosted an Asian citrus psyllid townhall meeting in Fresno in August. At the event, Grafton-Caldwell said it is vital to slow the spread of psyllid to new areas.

Along with conventional pesticide sprays, organic products have been tried to prevent spread of Asian citrus psyllid. However, the usefulness of the methods has come into question.

“We struggle with organics,” Grafton-Caldwell said, regarding organic sprays and powders. “They are short-lived and have to make direct contact with the psyllid. They are only good for hours or days and not for months.”

Information on monitoring for and treating Asian citrus psyllid and the disease it spreads is available online.

Posted on Wednesday, September 11, 2013 at 11:47 AM

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