The rumbling of two single-engine planes shattered the stillness of the predawn hours Monday in a spraying attempt to kill the grasshoppers that have been the county's most recent threat to farmers' fields.

Planes from Parowan Crop Dusting Service crisscrossed the fields 50 feet above the communities of Grantsville, Erda and Tooele while agents directed them with radios from trucks below.Able to carry just 110 gallons of the bitter-smelling chemical Malathion, the planes repeatedly landed and took off from the Tooele County Airport so their tanks could be refilled. About 14,000 acres will be sprayed through Wednesday.

Grasshoppers have already caused significant damage to residential gardens, grazing lands and some crops.

"This is by far the worst I've seen, both in terms of area and actual population numbers," said Brent Bunderson, who has worked as Tooele County's extension agent for four years. "People who have been around for a while say it's as bad as they've seen it."

Tooele County Commissioner Lois McArthur said she has heard residents complain that they can't send their kids out to play or see out their windows because the grasshoppers are everywhere.

If they don't kill them now, they will stick around until September, which will undoubtedly be devastating to farm crops, Bunderson said.

The crop dusting is a joint effort between the U.S. Department of Agriculture, Tooele County, Tooele City, the Utah Department of Wildlife Resources and the Grantsville Soil Conservation District. The county is coordinating the effort.

Bunderson said more acres need spraying but resources only allow them to cover the most critical places. The project is expected to cost about $21,000 overall. Funds were provided by the different entities and private landowners.

Crickets were the focus of the farmer's worries earlier this summer, but baiting techniques saved the fields just as the grasshopper problem began to work its way to the forefront.

Bunderson said he can't think of anything on which to blame the county's pest problems, but the wet spring provided plenty of succulent leaves for the bugs to eat.

Malathion acts as a muscle relaxation inhibitor that interferes with the grasshopper's breathing and nervous systems. The spraying should catch the grasshoppers before they lay eggs that would destroy fields next year. Female grasshoppers can lay up to 100 eggs in a season, Bunderson said.

Although the chemical doesn't affect humans, people in the area are advised to stay out of the path of the spray.

A few Tooele County residents expressed concern about potential long-term health risks that may result from spraying at a recent county-wide meeting, and a few individuals commented that they are supersensitive to chemicals.

Another point raised at the meeting was that the spraying would kill beneficial insects. But Bunderson said by far the majority of residents and farmers wanted to get rid of the grasshoppers.

"We had to weigh pros and cons of it, and we felt the community should do something about it," Bunderson said.

Bunderson said they have taken all of the precautions they can, even boxing up the bees in the area.

The planes are flying at least 500 feet away from homes.