A disease that's fatal to citrus trees has infected at least one more tree in California, only days after the state's second known case was identified, according to growers and local officials who spoke to CNBC.
And more trees beyond the two recently identified are believed to be carrying the disease, alternately called Huanglongbing, HLB or "citrus greening," said Joel Nelsen, president of California Citrus Mutual and a farmer based in San Joaquin Valley.
There is no cure for HLB; once a tree is infected, it can die in three to five years.
Two trees have been found on adjoining properties in San Gabriel, California, in Los Angeles County, said Ken Pellman, a public information officer for the Los Angeles County Agricultural Commissioner.
Los Angeles County is not an agriculturally productive county relative to others in California, but more than half the houses in the county have citrus trees in their yards, Pellman said.
Huanglongbing is a bacterial infection that is carried by a tiny insect called the Asian Citrus psyllid. Both the species and the disease originate in Asia but have spread to other parts of the world, including Mexico and the United States. Other large citrus-producing states such as Florida and Texas are already battling considerable citrus greening epidemics in their commercial groves.
California growers have avoided outbreaks so far, but Nelsen told CNBC the recent cases suggest "it is not looking good" for growers there.
A Huanglongbing outbreak could be disastrous for the California citrus industry, which has struggled this year in the face of severe water shortages and a strike at shipping ports in Southern California. The state is a major exporter of fruit to Asia.
Nelsen told CNBC that drought conditions have forced many growers to either cut back their trees or bulldoze less productive groves. Growers bulldozed somewhere around 10,000 to 12,000 acres of trees in 2014, and Nelsen expects a higher number of acres to be destroyed this year.
"Because of the cost of water, the drought conditions, Huanglongbing and the port strike, I think this is going to be our significant money-losing year (over the last) 10 or 12 years," Nelsen said.
A citrus tree—like most other fruiting trees—can take several years from the time it is planted as a sapling to produce commercially viable fruit.
China, the second-largest market for California citrus, shut out U.S. producers after shipping delays left cartons of rotting fruit in the wake of labor strikes early this year. Nelsen said he is hoping the country will reopen its markets to U.S. citrus soon.
California already spends about $25 million annually on citrus greening prevention. About $15 million of that comes from the industry, and the rest comes from a federally funded program to protect growers from the disease, Nelsen told CNBC.
Researchers in other states have attempted to find a cure for the disease or find a strain that is genetically resistant and graft it onto existing trees, but neither has produced a solution to the problem, Nelsen said.
"Even if you are optimistic about their scientific viability, both of those projects won't be commercially viable for three to five years," Nelsen said. "And then it can be another five years after that to get a fruit crop out of your trees."
The California strategy has centered on detecting cases early, mostly by sending state and local government employees into areas known to have large populations of psyllids and checking trees. That's mostly been in residential areas, including the Los Angeles area. The hope is that they catch cases before they have a chance to spread to commercial crops.
Inspectors look for yellowed leaves or misshapen fruit—two symptoms of the disease—and send samples back to laboratories for analysis.
There is no other way to tell if a tree is infected, which makes the disease hard to detect and leaves surrounding trees vulnerable to infection in the meantime.
"You can tell the tree is stressed, but you can't tell why," Nelsen said.
Once a case is confirmed, the state pays to have the entire tree removed, including the entire root structure, which can be a reservoir for the disease.
So far, homeowners involved have been cooperative in allowing trees to be inspected and removed.
Even though HLB is infecting far more trees in Florida, it could end up being a bigger problem for California if it infects Golden State groves.
Most of the oranges grown in Florida are used for juice, and farmers can still use some bitter, HLB-infected fruit for juice, diluting it with juice from sweeter, healthier oranges to mask the taste.
But California sells mostly whole fruit, in fact it is the country's largest supplier of whole citrus.
"No one is going to buy a bitter orange, so it is a big concern," Pellman said. "If you want to buy local, and especially if you want organic, you do not want citrus greening in California."
CORRECTION: Two trees have been found to have Huanglongbing in San Gabriel, California, in Los Angeles County. The name of the town was misstated in an earlier version of this article.