News Releases

Fears Realized: Deadly Threat To California Citrus Found South Of Border

Citrus Industry Leaders Warn Disease Will Affect Consumers’ Backyard Trees

VISALIA, CALIF. – Aug. 18 , 2009 –  What the California citrus industry fears most is happening – the deadly Huanglongbing disease is taking hold in Mexico, looming too close for comfort for California growers as well as homeowners with backyard citrus trees.

Huanglongbing, also known as HLB and citrus greening disease, is a bacterial plant disease that – while not harmful to human health – destroys production, appearance and value of citrus trees, and the taste of their fruit and juice.  Once a tree is infected with the disease, there is no cure and the tree will eventually die. The disease is spread by the disease-carrying Asian citrus psyllid, an aphid-like insect, which made its way into Southern California last summer. Presently, tests of psyllids found in Southern California trees have found no presence of the disease, but officials warn it is only a matter of time as the disease migrates toward California.

Mexico’s plant health agency, Sanidad Vegetal, confirmed this month that HLB had been found in six citrus trees in El Cuyo, which is located on the 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.

These latest discoveries of HLB ring a warning bell to California citrus growers and homeowners who have backyard citrus trees, said Ted Batkin, president of the California Citrus Research Board.

“It’s like Mary’s little lamb,” said Batkin. “Everywhere the pest goes, the disease is sure to follow. The only way to save California citrus is to control the psyllids, and the public plays a critical role in that process. If the disease gets a hold in California citrus, homeowners and growers in California will face a great peril – HLB-infected trees may need to be removed to prevent the disease from spreading to other trees.”

In June 2008, the psyllid was identified in Tijuana, Mexico; a few short months later, it was identified in San Diego County and then, before long, in Imperial County. A quarantine has been established to prevent movement of the psyllid on host plants.

“This pest and disease can be catastrophic not only to local farms and farmers that we count on for our fresh, healthy, locally produced citrus, but also consumers’ ability to grow citrus in their backyards,” Batkin said.

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. The severity of the problem and the necessity to act fast and cooperatively was the tone of the meeting, as representatives from the three countries shared information on practices, including eradication efforts for the pest.  Other topics addressed include diagnostic laboratories and procedures; psyllid control issues, such as pesticides and natural enemies; communication strategies; and nursery protection plans.  Attendees will meet again next month in Monterey, Mexico.

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 www.CaliforniaCitrusThreat.org. If you think you have found a psyllid, act fast. Time is critical. Call the California Department of Food and Agriculture hotline at 800-491-1899.