Weather permitting, helicopters will finish their chemical spray battle against gypsy moths in residential east bench areas of Salt Lake County and Provo today.

National and state agriculture officials said Friday they will target Salt Lake County's Olympus Cove, Top of the World and the lower end of Little Cottonwood Canyon and Provo's foothills.Whatever areas they can't finish today, they will finish Sunday and Monday, they said.

Steve Munson, U.S. Forest Service entomologist from Ogden and a director of the spray program, said helicopters finished spraying the third and final application of the biological pesticide bacillus thuringiensis, or BT, on Bountiful's east bench residential area Friday.

He said less than half of the 20,000 acres in the spray target areas have been given the BT treatment.

"We expect to spray in the higher elevations in Davis, Salt Lake and Utah counties beginning Wednesday, May 30," Munson said. "These areas are mostly Forest Service lands where cold weather and high elevation have slowed the growth of oak brush and other vegetation.

"The leaves should be large enough to accept the spray, though, by this next week. If everything goes according to plan, we should be finished with this year's spraying program by June 17."