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Foreign oak beetles ravaging San Diego County

SAN DIEGO (AP) -- It's beetlemania in San Diego County. But there are no screams of joy.

Instead of an invasion from Britain, these exotic beetles -- gold-spotted oak borers -- hitched a ride into California on firewood more than 10 years ago, and have been wreaking havoc on old growth oaks and wildlife that uses the trees as habitat.

The beetles appeared in Marian Bear Memorial Park near La Jolla several years ago, and by last year had spread into the San Jacinto Mountains of Riverside County, UT San Diego reported Monday.

About $8 million has been spent clearing San Diego County's beetle-damaged trees, some of them oaks that were centuries old and provided crucial canopies for both animals in their habitats and humans seeking shady refuge.

“They're really the linchpin of an awful lot of ecosystems,” University of California natural resource specialist Tom Scott said. “It's sort of sickening to see how many trees have died and how many are in trouble. “It's one of the most dramatic changes we've seen to oak woodlands.”

Parts of William Heise County Park, near Julian, have become virtual oak graveyards, with the beetles blazing trails through the trees.

While some object, the park's supervising ranger Roger Covalt said they have no choice but to bring down the sickly oaks, which could topple and kill visitors, increase fire risk and infect other trees.

“Safety is the No. 1 concern,” Covalt said. “If there's a dead tree, we're going to drop it.”

Officials are warning against transporting firewood between regions and furthering the spread, and a network of volunteers has been enlisted to watch for the oak borers in new places.

What if San Diego County had no oaks in it?” asked one of the volunteers, retired state fire employee Mark Ostrander, who said he spends up to 30 hours a week walking among the trees looking for beetles in Jacumba in Southeastern San Diego County. “What do you think the landscape would look like? What would the parks be like?”

Scientists are looking to other regions for solutions.

The beetles are present on the oaks of Arizona but seem to have little ill effect.

That could be because Arizona's oaks evolved alongside the beetles and developed a resistance, unlike the California trees from the red oak family that seem especially susceptible.

It could also be that other Arizona insects keep the oak borers in check.

The top candidate so far is a parasitic wasp found in the Dragoon mountains that eat the beetle's eggs and larvae.

The wasp species is being tested in a lab for possible introduction to California, but it could take years before researchers learn whether that would be safe for other species.

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