San Dimas

The charred remains of about 3,000 pine trees on a hillside in Frank G. Bonelli Regional County Park may become infested with tree-boring insects unless the dead wood is cleared away soon, a county forestry official said. The trees were burned Aug. 25 in a 350-acre fire started by a motorist who threw a cupful of burning gasoline into the brush along the Foothill Freeway, park officials said.

Paul Rippens of the county Fire Department’s forestry division said the trees are now vulnerable to attack by the bark beetle, an insect that feeds on diseased or dying trees. He said a beetle infestation would jeopardize about 1,000 trees that survived the fire as well as other trees in the park, and called upon the county Board of Supervisors to order the dead trees removed as soon as possible.

Rippens, who is helping draft a removal plan to be presented to the supervisors next week, said the beetles typically begin to infest scorched wooded areas within six weeks of a fire. “They can be stopped with chemicals, but we’d just as soon remove the hazard,” Rippens said. The damaged trees are among 7,000 planted in the park by the county in 1973.