Chemical warfare against the gypsy moth in Mount Olympus Cove is expected to start between May 8 and 12, Utah Department of Agriculture officials said Thursday.

They will meet with other government agencies at 1 p.m. May 3 at Utah State University's Salt Lake County Extension office, 21st South and State Street, to narrow down the target date for spraying Bacillus Thuringiensis insecticide, or B.t.Utah Department of Agriculture spokesman Mark Quilter said the spraying will be done from helicopters flying 50 to 100 feet above the 1,190-acre target area east of I-215, south of Parleys Canyon and north of the boundary of Mount Olympus with Wasatch Boulevard.

Quilter said a test of the helicopters' ability to spray the right amount of chemical on the right areas will be conducted Wednesday beginning at 6 a.m. at Salt Lake Airport No. 2 in west-central Salt Lake County.

"We'll lay down cards on the ground and spray the area and then check to see how much B.t. was sprayed on the cards. We'll report on the tests at the afternoon meeting."

He said a quarantine, which started earlier this month in a 6,000-acre area including the 4,500 homes in Mount Olympus Cove, is working out well. "We pretty much left it up to the homeowners to check their recreational vehicles, camping equipment and boats for gypsy moth eggs."

He said these items cannot be moved from the area without an inspection and the issuance of an inspection sticker. Limbs, trees and landscaping materials and trash cannot be taken from the area, except by regular trash haulers.

The quarantine will last until the gypsy moths problem is over, agriculture officials say.

Van E. Burgess, the state Agriculture Department's director of plant industry, said the moth, if left unchecked, could destroy fruit trees, oak and other hardwood trees and watershed - costing millions of dollars.