Huanglongbing Detection in Mexicali Puts Pressure on California Citrus Growers and Residents to Protect Their Trees

Mexico and the United States are Working Collaboratively to Prevent
Spread of the Disease in the Cali-Baja Mega Region

MEXICALI, Mexico–(BUSINESS WIRE)–The deadly and incurable citrus tree disease Huanglongbing, also known
as HLB or citrus greening disease, was detected 23 miles south of the
U.S.-Mexico border in a small citrus grove in Mexicali.

HLB kills citrus trees and has no cure. The disease is spread by a pest
called the Asian citrus psyllid as it feeds on citrus tree leaves and
stems. The HLB detection in Mexicali was in a single citrus tree, and a
single Asian citrus psyllid tested positive for carrying the bacteria
that causes the disease as well. Agriculture officials in Mexico are
working quickly to survey the surrounding citrus trees, as a part of
their ongoing efforts to protect Mexico citrus from this devastating
plant disease through monitoring, removal of diseased trees and Asian
citrus psyllid treatments.

In California, local and state agriculture officials are also monitoring
citrus trees in the border region, placing insect traps, releasing a
natural predator of the Asian citrus psyllid and conducting treatments
to protect citrus trees from the pest.

“With Huanglongbing now detected in Mexicali, Ensenada and Los Angeles,
Southern California citrus growers – including commercial farmers and
residents who have orange, lemon or other citrus trees growing at their
homes – must be on guard,” said Victoria Hornbaker, citrus program
manager for the California Department of Food and Agriculture.

“Huanglongbing knows no borders. Residents throughout this region must
work together,” she said.

The Citrus Pest & Disease Prevention Program recommends the following
actions to protect the community’s citrus trees:

  • Do not move citrus fruit, plants or cuttings. Obey federal and
    state quarantine laws that limit the movement of citrus material into
    and out of the region. These measures are in place to prevent diseased
    plants and the Asian citrus psyllid from being transported to new
  • Cooperate with agriculture officials. Trained agriculture
    specialists are scouting citrus trees in Southern California,
    collecting plant samples and treating citrus trees to protect against
    the Asian citrus psyllid. By working together with these agriculture
    crews, residents will help protect their community’s citrus.
  • Protect citrus trees against the pest. Ask your local nursery
    or home and garden center what products can help protect your citrus
    tree from the Asian citrus psyllid. The best way to protect against
    the disease is to stop the pest.

The first detection of HLB in California was in Hacienda Heights in
2012. In 2015, multiple incidences of the disease were found in San
Gabriel, a nearby community. A total of 27 diseased citrus trees have
been detected and removed, all within Los Angeles County. In Mexico, HLB
was detected in Ensenada earlier this year. The disease is also present
in southern areas of the country. Agriculture officials from both
countries are working collaboratively to prevent the disease from

For more information on the issue, visit or


Nuffer, Smith, Tucker
Katie Nieri, +1 (619) 296-0605 ext. 254