Agriculture
12:23 pm
Tue September 10, 2013

Tiny Bug Has Central California Citrus Growers On Edge

Throughout Central California those who work in the citrus industry are on edge.  A tiny insect, no larger than an aphid, is threatening the future of the state’s billion dollar citrus crop.

It’s known as the Asian Citrus Psyllid.

“It looks kind of like an aphid, only with a harder body, and a little bit browner," says Beth Grafton-Cardwell, an entomology specialist with the University of California at the Lindcove Research Center just west of Visalia.

And the creature’s babies are just as pleasant.

“The nymphs are little yellowish things that plaster themselves to leaves and stems," Grafton-Cardwell says.

This little bug packs a big punch; just one bite into the leaves of a tree is all it takes for the insect to spread the bacteria that causes huanglongbing, a disease also known as HLB or citrus greening. It alters the production, appearance and economic value of citrus trees, eventually killing them.

“Huanglongbing devastates the root system and the nutrition of the tree, so early symptoms are yellowing of the leaves and gradually the fruit becomes small and hard – the juice tastes bitter - and eventually the tree dies," Grafton-Cardwell says. 

"If we can keep the psyllid from turning into the tree disease we'll avoid the problems the state of Florida has run into - they now have 200,000 acres of diseased trees." - Assembly Member Jim Patterson

HLB is considered to be one of the most serious threats to the citrus industry in the world – and at the moment there is no cure.

So far the worst U.S. case of HLB has been in Florida, where over 32 counties have been infected. Since 2006, the disease has cost growers there over $3 billion dollars, and thousands of jobs. The psyllid was first detected in Southern California in 2008 and last year it made its way to Tulare County.  

This week two psyllids were found in Dinuba on a backyard tree prompting an even larger need to educate the public, says Grafton-Cardwell. 

Assembly Member Jim Patterson recently held a town hall meeting in Fresno to bring together state and local experts on the disease.

“This is a huge issue at stake here," Patterson says. "Ten thousand jobs here in California and a billion and a half dollars of crop value is at risk and if we can keep the psyllid from turning into the tree disease we’ll avoid the problems the state of Florida has run into – they now have 200,000 acres of diseased trees.”

Since that town hall in late August, another county has been added to the list. Last week, in the Kern County community of Wasco, one tiny psyllid was found in a back yard garden plastered to a piece of yellow sticky paper - known as a glassy winged sharpshooter trap. That’s just weeks after six psyllids were found in Tulare County.

In Wasco, Glenn Fankhauser Assistant director of Agriculture in Kern County says finding even one psyllid shouldn’t be taken lightly.

“By itself the psyllid isn’t detrimental to the citrus industry and the state as it would be if huanglongbing citrus greening were present in some tree," Fankhauser says. "If we had both of them together that would be a problem.”

That is why the ag industry in California has launched a campaign to prevent the spread of the disease.

Joel Nelson, president of statewide trade association California Citrus Mutual, and others across the state want to keep California’s $2-billion citrus industry free of the devastation that has plagued Florida, China, Mexico and Brazil

Credit Ezra Romero / Valley Public Radio

“It’s either them or us," Nelson says. "So it’s an all-out war. If we don’t stop the spread of the Asian Citrus Psyllid and if we don’t find huanglongbing before it finds the industry we’ll lose the California citrus industry."

Here’s the good news: While the psyllid has been spotted in several counties, so far the bacterial HLB disease has only been found in one tree in the state.  It made its way to California through what citrus experts say is per usual – a backyard citrus tree - this time in Southern California. The tree was quarantined and has since been pulled and is being analyzed.

When a citrus psyllid is found on a sticky trap, officials set up a quarantine extending for 5 miles around site. That means increased inspections and measures to prevent the pest from hitching out of the zone, either on nursery trees, or in leaves or twigs that can sometimes accompany freshly picked fruit.

Some farmers are even taking the battle to the airwaves.

Severns says that if the psyllid thrives in Central California, he an every citrus farmer has a case to worry.
Credit Ezra David Romero / Valley public Radio

Second generation citrus grower Kevin Severns from Orange Cove, Calif., is the voice behind a public service announcement about the disease.

“When you see your own grove, your own trees that you work hard to keep thriving and you realize that if HLB takes hold that could all go down very quickly," says Severn, who is the general manager of the Orange Cove-Sanger Citrus Association.

Severns says he’s surprised how a creature so small could inflict so much damage.

“It’s not the things we see and that are the most obvious that wind up being our biggest adversaries, it’s the ones that are difficult to see and that are insidious that creep in slowly," Severns says. 

That is why he has joined a statewide movement to wipe out any psyllids that make their way to Central California.

While commercial growers have the most at risk, state officials say anyone with a backyard citrus tree needs to be aware of the issue.  

"This is not just a commercial problem, but a homeowner problem because 60 percent of Californians have at least one citrus tree in their yard." - Beth Grafton-Cardwell

“This is not just a commercial problem, but a homeowner problem because 60 percent of Californians have at least one citrus tree in their yard," Grafton-Cardwell says.

The same officials say that education about the psyllid is crucial because the fate of the citrus industry is now in the hands of both farmers and residential gardeners.

“The average layperson can learn just what a psyllid looks like and what huanglongbing symptoms look like in a tree so they can alert the authorities especially if they are in the San Joaquin Valley where all of this is new," Grafton-Cardwell says.

Grafton-Cardwell says homeowners can take a few action steps: get to know the bug, report it if you see it, allow authorities to treat your trees to kill the psyllids and to not move plant material around the state because the psyllid could be riding on it.

The latest discovery of the psyllid in Kern County may be an indicator of what is to come for citrus in Central California, but farmers and ag advocates will put up a stiff fight before HLB becomes a reality in the region.