Asian pest threatens California’s citrus industry

Citrus is an iconic part of California life. By some estimates, up to 70 percent of homeowners in the state have at least one citrus tree on their property. But all of these trees are now in danger, and the threat is a tiny insect, smaller than a chocolate sprinkle.

The insect is the Asian Citrus Psyllid, also known by its Chinese name Huanglongbing. But the psyllids themselves don’t kill citrus trees. They’re merely the agent that spreads the infection.

An infected psyllid acts much like a dirty syringe, flying from tree to tree, feeding and depositing a bacterium, each time unfurling its needle-like mouth, much like a mosquito.

The disease was first spotted in 2005 in South Florida and quickly spread throughout the citrus-growing region. In March 2012, state inspectors found a tree in a front yard in Los Angeles County that was infected with citrus greening.

California is the country’s biggest supplier of fresh-market oranges, and its 285,000-acre citrus industry is second only to Florida, according to California Citrus Mutual.

Having seen the havoc the insect could wreak, agriculture officials have enacted quarantines covering all or parts of 12 counties, including Santa Barbara, Ventura, Los Angeles and San Bernardino, which restricts the movement of citrus trees and requires labeling of citrus nursery stock.

Since 2010, California growers have spent about $15 million yearly to fight the psyllid. Much of that money goes toward massive detection and awareness efforts. Recently however, the U.S. Department of Agriculture (USDA) said that it would set aside $1.5 million to scale up breeding and release efforts of a tiny parasitic wasp, a natural enemy of the psyllid, in three states: California, Texas and Florida. An additional $125 million appropriated by Congress will be spent over the next five years to fund research into other methods to contain the spread of the disease.

Karen Moss, of the Lemon Ladies Orchard in Redwood City, wishes she knew more about the steps local agencies were taking, as she currently lives in fear of losing her orchard.

Moss, who names each of her trees after women who inspire her, clasped her hands together and said: “It would break my heart to lose my orchard,” she said. “But I’m a big believer in positive thinking.”

The adult Asian citrus psyllid is pictured here. (Photo courtesy of R. Anson Eaglin, APHIS via U.S. Department of Agriculture's Flickr.
The adult Asian citrus psyllid is pictured here. (Photo courtesy of R. Anson Eaglin, APHIS via U.S. Department of Agriculture’s Flickr.


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