BUGGED TO DEATH OLEANDERS BEING WIPED OUT BY INSECT.

Byline: Lisa Mascaro Staff Writer

Slowly but surely, the sturdy, showy oleander - a staple of Southern California's landscapes and freeway shoulders for years - faces eradication as a bug known as the glassy-winged sharpshooter spreads a deadly bacteria from plant to plant.

While the half-inch-long insect has posed a grave threat to the state's prized wine grape crop in recent years, its devastation of the lowly oleander has drawn less attention, except from Caltrans crews ripping out diseased and dead plants.

Experts say as many as half of the oleanders in Southern California are now infected with the bacteria that causes leaf scorch, and it's only a matter of time before the landscaping mainstay is gone for good. They also worry the problem could spread to liquidambar, olive and purple leaf plum trees - all popular with landscapers.

``It hasn't generated a lot of interest because, as I tell people, the oleander is the Rodney Dangerfield of the plant world,'' said Matthew Blua, an entomologist at the University of California, Riverside. ``It doesn't get much respect.''

State agencies have poured $137 million over the past 3 1/2 years into fighting the glassy-winged sharpshooter infestation because of the potential harm to the state's wine industry. They are attempting to contain the infestation to Southern California and are using wasps to try to kill off the sharpshooter, which is spreading ``xylella fastidiosa,'' the bacteria that causes leaf scorch, to the oleanders.

``It is quite extensive throughout Southern California. You can see it a lot on the freeways, but you can see it everywhere,'' said Jerrold Turney, a plant pathologist at the Los Angeles County Department of Agriculture's office in South Gate, where diseased oleanders decorate the building.

``In the next five to 10 years, all of the oleanders are going to die in Southern California. Some plants may survive - you may have a few here and there not affected - but the vast majority of oleanders are going to die.''

Calabasas' popular Sperling Nursery no longer keeps the flowering evergreen on hand and steers homeowners to other landscaping alternatives, said sales associate Kathy Post.

``Oleander was such a nice plant because it produced a color - and the color stayed - with the pinks, the whites and the reds,'' said Post, a 10-year employee who started seeing leaf scorch in the San Fernando Valley three to five years ago.

``Obviously, Caltrans knew what they were doing when they planted it down the middle of the 110 Freeway; they handled the heat, they handled the dry,'' she said.

``Hopefully it will make a comeback.''

Oleander, the hearty, poisonous shrub that's lined Southern California freeways and decorated its yards for decades, first started showing signs of leaf scorch in the early 1990s.

Searching for the source, scientists homed in on the sharpshooter, a large insect with transparent wings that arrived in California in 1989 from its native habitat in the Southwest and Mexico, and began transmitting Pierce's disease across Temecula's vineyards.

Pierce's disease had long been present in California's wine grape crops, but growers had it under control until the sharpshooter - with its voracious thirst - started feeding on vines and, in the process, transmitting the xylella fastidiosa bacteria.

The sharpshooter also reluctantly feeds on oleanders, and in no time, it transmitted a different strain of the bacteria to those plants.

The bacteria cuts off the plant's water system - ``clogs up the pipe,'' as Turney puts it - resulting in leaf scorch and ultimately killing the plant.

``It feeds like a little monster. If you've every seen it go, it can drink many, many times its own body weight every single day,'' said Jay Van Rein, a spokesman for the state Department of Food and Agriculture.

Turney estimates that 25 percent to 50 percent of the region's oleanders are infected, while Caltrans figures at least half the oleanders lining the freeways in Los Angeles and Ventura counties are dying from the disease.

Experts worry that the infestation could hit other plants as well.

``There's a potential there we could see the exact same thing happening with liquidambar,'' Turney said. ``If it gets really serious in L.A., that'll be a bigger story than oleander because there are so many planted as street trees. That'll be a big expense for cities to go in and rip them out and replant.''

With no hope of ridding Southern California of the sharpshooter, the state spends most of its money inspecting nursery shipments to stop the pest from moving north - it's basically stayed below the Tehachapis - as well as researching a cure or treatment for the disease, he said.

``With the tools we've got right now, eradication isn't really possible,'' said Van Rein, adding that since 2000 the state has unleashed nearly a million tiny, stingerless wasps in Southern California as natural enemies to the sharpshooter.

``At least there's a line in the sand,'' he said. ``It would've been great if we could've stopped it before it got to Southern California, but at that point, no one knew it was here in the first place or carrying that bacteria.''

The state Department of Transportation had initially given $55,000 in grants to researchers to try to stem the problem, said UCR's Blua.

But now, Caltrans officials said they're focusing efforts on ripping out the oleanders and replacing them with new plants, as time and manpower permits. The department said there's no way to gauge the cost.

``The expense of removing affected oleander, and replacing them with plants not currently 'on the menu' for this insect, is extensive, given the number of dead and dying plants throughout the system,'' said Caltrans spokeswoman Judy Gish.

``The oleander plant has played a major role in the Southern California landscape and will be missed.''

For home gardeners, the advice from the experts is to remove the plants once they begin to show signs of disease. Trimming the dead parts will only delay the inevitable, as the infection will remain and the plant will die. Insecticides might help defer infection.

``I think people will be upset that they're gone, disappointed,'' Turney said. ``For a lot of people, they've been in their back yard for 30 years. They just ignore them. They bloom, they water them, they prune them back to the size they want. When they die, they're upset they're gone.''

Lisa Mascaro, [phone]

lisa.mascaro(at)dailynews.com

CAPTION(S):

3 photos

Photo:

(1 -- 3 -- color) A Caltrans worker checks an oleander along the 101 Freeway in Calabasas. An infected leaf is at left, while the culprit, the glassy-winged sharpshooter, is on top.

Michael Owen Baker/Staff Photographer

Andy Holzman/Staff Photographer

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