Citrus psyllid making growers more nervous

The California and Arizona citrus industry was already nervous with the discovery of citrus psyllid in Southern California.

Now it is quivering like an orange tree in an earthquake with the confirmation of the deadly disease vectored by the psyllid in Mexican citrus trees and the discovery of the tiny insect and the disease at an air cargo facility in the heart of the San Joaquin Valley.

Six citrus trees in Mexico’s Yucatan Peninsula tested positive for a disease that’s fatal to the trees and citrus psyllid was sniffed out by a canine agricultural cop on curry leaves confirmed to be carrying the disease at a FedEx cargo facility in Fresno, Calif.

The citrus industry is struggling to keep diseased insects out of the state’s major citrus region, which is led by Tulare County, a neighbor to Fresno County where Navel oranges alone are a $415 million crop.

The disease, Huanglongbing (HLB), causes citrus greening. It’s carried by a small winged insect called the citrus psyllid that is no bigger than an aphid.

“If it’s found here and becomes established, it will destroy the California citrus industry,” said Shawn Stevenson, a Clovis, Calif., grower. “You only have to look to Florida and other places where it has been a problem to see how devastating it can be.”

In Florida, more than 60,000 acres of citrus trees have been removed and billions of dollars in losses have been logged as scientists seek a cure.

Ted Batkin, who heads the California Citrus Research Board in Visalia, Calif., is fond of saying: “It’s like Mary’s little lamb, everywhere the psyllid goes, the disease is sure to follow.”

It takes both the psyllid and the disease to spread the disease, and the industry had for months been successful in efforts to find and treat psyllids that had found their way into parts of Southern California. This is the first time a psyllid has been found in the San Joaquin Valley, and the first time one with the disease has been found in California.

In early August, officials confirmed the find at the Fresno cargo facility by a dog with the Fresno County Department of Agriculture’s canine team. “One of the lessons we learned is that our dog teams work,” Batkin said. “It is much better to have early detection and response.”

He said the response in Florida was not as rapid, and the consequences have been dire.

Joel Nelsen, president of California Citrus Mutual in Exeter, Calif., said he did not see the discovery of the diseased insect on curry leaves at the Fresno facility as a good news-bad news situation.

“It’s mostly bad; it clearly shows how susceptible we are to a system breakdown,” he said. “All it takes is for a traveler to be malicious or naive. As a result, our industry could be susceptible to this disastrous disease.

“I’m thrilled that Fresno County inspectors performed well, but I’m not looking at it all that positively. How often is this happening and what can you do that protects agriculture?”

Because of the high costs of fresh fruit production, the California industry has still more to lose, Nelsen said.

“Florida growers pay an extra $600 an acre to stay alive until a cure develops,” he said. “Margins on juice revenues versus farming costs are not the same as for producing fresh fruit.”

Fresno County Agricultural Commissioner Carol Hafner praised the work of the dog team, including Chelsea, the 2-year-old Labrador retriever who sniffed out curry leaves carrying the insects, and the dog’s handler, Stephanie LeBarron, an agricultural standards specialist.

At a ceremony honoring the dog team’s efforts, LeBarron said, “I’m proud of Chelsea. I’m just the chauffeur; she probably runs 100 miles a day on the moving belt for packages.”

Hafner said the woman who packed the pests “was remorseful to the point of tears. Both she and her daughter were upset.”

“In India, everybody has a plot where they grow some curry, and the woman brought it back for her daughter,” Hafner said, adding no penalties will be leveled.

She said an unclaimed duffel bag containing the curry leaves was left in Los Angeles, where it had been transported from Dubai. It was then transported to the FedEx facility in Fresno.

The bag contained one dead adult psyllid and nine nymphs “believed to be alive,” Hafner said. One of the nymphs tested positive for the disease.

Trapping for the insect and inspection for greening was started Aug. 11, in a roughly one-square-mile area near the traveler’s home in Fresno. Neither the disease nor additional psyllids were found, said Art Gilbert, senior agricultural biologist with the California Department of Food and Agriculture.

Gilbert said about 100 traps were distributed and they will be checked every two weeks through October.

Hafner said the state is adding additional detection dog teams in cities that include San Diego, Santa Clara, Contra Costa, and Los Angeles. The Fresno team is one of five in the state; the others are in Contra Costa, Sacramento, San Bernardino, and San Diego.

Just days after the Fresno discovery, the U.S. Department of Agriculture announced an advertising campaign including attention-getting videos aimed at raising awareness of invasive pests and their threat to California agriculture and the environment.

California is especially vulnerable to invasive pests because of the state’s large seaports and high volume of international travelers, said Larry Hawkins, public affairs officer with USDA’s Animal and Plant Health Inspection Service.

The advertising campaign, which includes print, radio and television ads, has the catch phrase “They’re here and they’re hungry.” The campaign is supported by the Hungry Pests Coalition, whose members include a number of agricultural organizations.

Hawkins said deliberate smuggling of plant material across borders can result in penalties. Air travelers are routinely asked to fill out a form when traveling from a foreign country, indicating whether they have agricultural items or have been on a farm.

“If you state you have agricultural items, you’ll be asked to present them for inspection,” he said. “If it is an agricultural item that can’t enter the United States, it could be seized with no penalty to you.”

But if a person is deceptive when asked for a declaration, he said, “a civil penalty will apply.”

“We count on the public to assist us in keeping items out of the country that cause harm, that’s a tall order,” Hawkins said. “We need to ask every resident to be sufficiently aware to remember to tell visiting relatives or friends, ‘Even if it’s traditional to bring me a basket of fruit or a bouquet of flowers, please don’t do that.’”

At the ceremony honoring the dog team, citrus grower Kevin Severns presented Chelsea with a basket of toys to show his industry’s thanks.

“We feel like we’re staring down a gun barrel and can see the trigger finger twitching,” said Severns, general manager of the Orange Cove-Sanger Citrus Association. But he said he appreciates efforts that state, federal and county agencies have been making to keep the disease at bay.

Asked how serious the threat is, Chris Lange, who grows a variety of citrus in Tulare and Fresno counties, said, “All consumers of citrus, as well as producers, have got to be extremely alarmed. Greening is a threat to citrus worldwide, reducing the ability to grow citrus in major production areas that include South America, Asia and Florida.

“It’s an epidemic that’s getting worse. In the scariest scenario, if this takes hold worldwide, we could see citrus as part of our diet become a thing of the past.”

Lange emphasized that the threat is to all citrus. His crops include navel oranges, Valencia oranges, tangelos, grapefruit, lemons, limes, and mandarins.

“Everything is vulnerable,” he said. “One psyllid has the ability to wipe out a mature orange tree.”

Mexico’s plant health agency, Sanidad Vegetal, confirmed in August that HLB had been found in six citrus trees in El Cuyo in Yucatan peninsula and near the city of Merida. Merida, located several hundred miles north of Belize, is the site where a positive HLB psyllid was found in early July. At a U.S.-Mexico summit in late June, where scientists, industry leaders and regulators discussed collaborative efforts, attendees learned HLB had also been discovered in Belize.

Authorities in the U.S. and Mexico are working collaboratively on solutions. In June, leaders in science, academia and government from both sides of the U.S.-Mexico border, including Belize, met to discuss the issue.

Batkin emphasized that many of the psyllid finds in California are a result of the homeowners’ diligence in inspecting their trees, and he added that both homeowners and growers need to continue their efforts. For more information and to find out what to look for, visit

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