Scientists study oak-killing Calif. beetle

DAVIS, Calif., May 5 (UPI) -- U.S. Forest Service scientists say they've completed a study of a beetle that has attacked 67 percent of the oak trees in an area 30 miles east of San Diego.

The study focused on Agrilus coxalis, a wood-boring beetle that the scientists said is so rare it hasn't even been given an accepted common name. Scientists have proposed the insect be named the goldspotted oak borer.

Land managers and scientists are concerned about the spread of the infestation because oaks are the dominant tree species in the region and tree mortality will increase fire danger and decrease wildlife habitat. The researchers are also concerned drought and climate change will make more oaks susceptible to an insect that is not native to California.

"We don't know how the beetle arrived … because there's a broad barrier of desert around the localities where it was previously collected in Arizona, Guatemala and Mexico," said Steve Seybold, a Forest Service entomologist and one of the study's authors. "We suspect it was either recently brought to California or somehow expanded its range."

Seybold and Forest Service Entomologist Tom Coleman estimate the infestation has impacted 17,000 trees in the Cleveland National Forest's Descanso Ranger District.

The study appears in the journal The Pan-Pacific Entomologist.