Utah Department of Agriculture officials Friday warned farmers and watershed managers that a devastating new pest - the gypsy moth - has been sighted in Utah for the first time, and its spread could mean millions of dollars in damage.

Deputy Commissioner of Agriculture Edison Stephens said Friday Utah scientists and agricultural experts reported seeing gypsy moths in July along the east bench in Salt Lake City. Since then, sightings in other areas of the state have been reported."We just received word this past week of 30 male gypsy moths being found in one trap in the Holladay area.

"This is the first time the pest has been reported in Utah, and if it cannot be stopped, there is no end to the damages the moth can cause to Utah's fruit trees and trees of all kinds, especially hardwood trees like oak that are so important to our watersheds," Stephens said.

Crop damage from grasshoppers in Utah in 1985, one of the worst years on record, was more than $53 million, and the cost of spraying 1.3 million acres totaled more than $3.35 million.

Stephens said the damage caused by gypsy moths could be as bad or worse than grasshoppers and crickets and could cost the state a lot more money in both damage and eradication expenses.

He said a meeting was held Thursday at the Utah Department of Agriculture headquarters for land managers, U.S. Forest Service officials, florists, nurserymen and University of Utah officials to discuss the moth.

"We heard from one of the nation's foremost experts on the pest, Victor Mastro of the U.S. Department of Agriculture's experimental station in Massachusetts.

"He warned that the gypsy moth could destroy the state's fruit industry and cause devastation on watershed hillsides above our streams, rivers and reservoirs _ contaminating our drinking water with so much silt from soil erosion that it could cost water districts millions of dollars to purify our culinary water systems."

Stephens said gypsy moths have destroyed thousands of acres of forest land in other states and caused untold damage to fruit and shade trees. "In Oregon, they put up 25 helicopters in one area at one time just to spray against gypsy moths, the devastation was so great a threat."

He said gypsy moth caterpillars eat the foliage on trees and can denude an entire forest in two or three weeks.

"On Monday, we will put out 500 traps from St. George to Logan to identify where the gypsy moths are and the extent of their infestation into Utah."

Stephens said nothing can be done to eradicate the gypsy moth from the state until early next spring. "Then we will begin spraying and take whatever action we can."

Gypsy moth caterpillars hatch in the spring and reach their full size of 3 inches by midsummer. They are brown with tufts of hair and have five pairs of blue spots and six pairs of red spots on their backs. The insects emerge as adult moths after seven to 18 days in loose cocoons.

The male moths, brownish gray with irregular dark marks, are strong fliers. The females are much larger and cream white with contrasting dark marks. The females fly little, if at all, and lay masses of 400 to 500 eggs, chiefly on tree trunks.

"We toured areas Thursday where gypsy moths had been sighted and found egg masses, so we know we will have trouble next year," Stephens said.

In many areas of the country which have been infested with gypsy moths, especially in New England, Middle Atlantic states and in Canada, eradication has included the collection of egg masses, which are then burned or treated with creosote, and the spraying of trees with insecticides, such as carbaryl.

Sprays that contain bacteria harmful to gypsy moths have been used. Banding trees with a sticky substance called tanglefoot has had some success.

Another pest new to Utah, the Russian wheat aphid, was also sighted for the first time in Utah this summer, but Stephens said its extent or problems it could cause have not yet been assessed. "We are watching this pest closely."