Borer Is Back : Doing Battle With Those Pesky Beetles

Times Staff Writer

Officials and residents in Palos Verdes Estates are looking for ways to combat an invasion of the pernicious Australian eucalyptus borer beetle, which is having a significant impact here on eucalyptus trees. The beetle was first noticed in the South Bay two years ago.

Combatting the pest, whose larvae kill the tree, took center stage at last week’s City Council meeting. The human-against-beetle battle here is made difficult for a variety of reasons: the city has little money to fight the insect, dense stands of eucalyptus provide a perfect home for the beetle and there is no insecticide that can kill the bug.

A Los Angeles County forester estimates that up to 80 trees already have been killed by the beetle here. The city is holding off on announcing the numbers actually killed and affected until it surveys trees in city parklands, where eucalyptus and other vegetation grow wild.

“It won’t wipe out our eucalyptus trees, but it is a serious problem and one that does not have an easy solution,” said Councilwoman Ruth Gralow, who presided over the packed council meeting last Tuesday. “We have to assess the problem a little more . . . so we can decide how aggressive we can be.”


Residents’ Concerns

But many residents have a more agitated view of the situation.

“If the city lets this go and does not adopt a well-thought-out forestry plan, this is going to look like a wasteland and it’s not going to take very long,” said George Kranen.

Paula Wicks, a resident of Via La Selva--where hundreds of stately eucalyptus dominate the landscape--first brought the beetle issue to the council earlier last month. “This is your chance to lead the peninsula on battling the beetle,” she told city leaders at the meeting last week.


Reacting to residents’ concerns, the council is forming a committee made up of members of the city parklands committee, staff members and residents. It will report on the extent of the infestation and devise the best ways to combat it in parklands, along streets and on private property.

And on Tuesday, city forester Walter Warriner will propose to the council steps that can be taken to remove dead and infested trees and to protect healthy trees on city parklands and streets within his annual budget for tree care. “I have $100,000 for a total of 14,000 trees,” he said.

Gralow said that without an alternate source of money, city work must be done with available funds. “We do not have extra money for this,” she said. Gralow said the city will inform homeowners how they can protect their own trees.

No insecticide has proven effective against the beetle, but entomologists are pinning hopes on an Australian wasp that lives only on the borer beetle and has protected Australian trees from infection.

Hardest hit in the city are the Valmonte area--including Via La Selva--near the Palos Verdes Estates-Torrance border, canyons in the vicinity of Malaga Cove, and Paseo del Campo near the Palos Verdes Golf Course, Warriner said.

The first significant South Bay infestation was reported on Santa Catalina Island in March. Officials said the beetle has destroyed hundreds of eucalyptus on the island. The beetle is a particular threat to Catalina because of the large number of eucalyptus trees there.

Elsewhere in the South Bay, officials say, there has been some infestation in Rolling Hills Estates, Rolling Hills, Rancho Palos Verdes, San Pedro and Torrance, but not to a significant extent. Rolling Hills Estates is considering putting an article in the city newsletter about how trees may be protected from the beetle.

According to county and state foresters, the inch-long, blackish-brown longhorn beetle--which apparently entered the United States in 1984 at El Toro in wood shipped from Australia--attacks only “stressed” trees. These are eucalyptus that are too close together, suffering from disease, lack water or are growing in poor soil.


Trees are killed through extensive damage done by beetle larvae--individual females may lay 200 to 300 eggs that girdle trees with tunnels as they grow, killing the trees. Healthy trees survive by drowning newly hatched larvae in sap.

‘Aggressive Flier’

During the last four years, the infestation has proliferated from San Diego to Ventura counties.

Eric Oldar, regional service forester with the California Department of Forestry and Fire Protection, said the beetle is an “aggressive flier” that can travel as far as 9 miles. However, he said such a major factor in the spread of the beetle has been tree-cutting companies that have sold infected firewood.

Trees may be protected by such means as regular watering, thinning of trees, pruning only during winter and early spring when adult beetles are not active, and removal of infested wood. Removal requires such precautions as burying tainted wood or tarping it for six months so the drying process will kill the beetle.

Said Warriner: “If you remove stressed trees, you take away a suitable host for the beetle and the trees left behind have a better chance to survive. There is less competition with other trees and more nutrients will be available.”

Los Angeles County Fire Department senior deputy forester Paul Rippens said Palos Verdes Estates parklands--which are thick with trees that have little water due to drought conditions--invite the beetle, which he estimates has killed up to 80 trees in the city in the last two years.

Counting Trees Now


City forester Warriner, however, said he is “counting trees right now” and he declined to say how many trees the beetle has killed. He said there are “quite a few dead trees” that could have died for a variety of reasons, but he conceded that “more than likely the major portion died from the beetle.”

Warriner said artificially watering parklands through drip irrigation is one option he is considering, but he said it probably is too costly.

Both Gralow and Warriner said the beetle crisis is prompting a new look at city policy to leave parklands wild and untouched. “The concept is up for review,” Gralow said.

Warriner said he first noticed evidence of the beetle in the city in 1986, but it was not until late this summer that it “blossomed” into a severe infestation.

A lifelong peninsula resident, Wicks said the Via La Selva neighborhood lost its first tree to the beetle a year ago but it was not until last month that people began noticing trees leaking sap and concluded that there may be beetles.

She held a public meeting Sept. 21 at a Redondo Beach savings and loan association to inform people about the beetle infestation and how to combat it.

At last week’s council meeting, she made several proposals, including a moratorium on tree trimming between April 1 and Oct. 1, removal of infested trees, compulsory covering of eucalyptus woodpiles and retention of an outside forester to identify trees that should be removed.

Oldar and others fighting the beetle hope that a state law that takes effect Jan. 1 will reduce the problem. It prohibits the movement of beetle-infested wood. Violators are subject to a fine of up to $1,000 and six months in jail. He conceded, however, that the law will be hard to enforce. “It depends on how big an issue infestation becomes,” he said.

Laboratory Research

A. D. Ali, an entomologist at UC Riverside, where the effectiveness of the Australian wasp is being researched, said a wasp population is being built. But he said it’s been “slow in coming along” because it is difficult to raise them in the laboratory.

“It does not look like we’ll see any wide area release for another year or so,” he said, adding that there will be no significant effect on the beetles for three or four years after that.

And even then, he said, it will not be a “cure-all” able to eradicate the beetle. “It will hopefully bring its population down substantially,” he said.

Times Community Correspondent Ann Johnson contributed to this story.