Despite wildlife officials' warnings about its hazards, a seller and a sprayer of the toxic pesticide Disyston are defending its use on northern Utah fields.

Grant Adams, owner of the Intermountain Farmers Association store in Tremonton, said it was his business that supplied most of the Disyston sprayed on about 15,000 acres of wheat and barley in northern Box Elder County.The pesticide is considered effective in controlling Utah's first infestation of Russian wheat aphids.

However, the state Division of Wildlife Resources has warned hunters the spray is among the most toxic of pesticides, and any wildlife taken through January in the area should be eviscerated, skinned and have the fat removed before being eaten.

On Wednesday the division said it had found a partridge that will be tested for possible Disyston poisoning because of "strange flight patterns." It is the first animal to be so tested since the warning was issued last week.

Adams said he sold 1,000 gallons of the spray earlier this month. He normally sells about 100 gallons of Disyston to kill spider mites in corn.

The spray has been in use for years in Box Elder County, he said, although not on the scale seen this fall.

"The public thinks we've pulled some secret chemical out of the hat," he said. "It's not a secret new spray."

Richard Kent, of Fielding, one of the half-dozen licensed pesticide applicators in the county, said he has sprayed 3,500 acres with Disyston.

Of the concerns over wildlife contact with the pesticide, he said it's been "blown out of proportion . . . Utah State University extension services people came out and said, `Hurry, let's spray.' Then the public reacts and they say, `well, maybe not.' "

The USU experts, pesticide suppliers and the farmers all agreed Disyston is the best way to fight the aphid, he said, adding that without the chemical, many northern Box Elder farmers could face financial ruin.

"Who's to say (a farmer) wouldn't suffer a 50-percent reduction in his crop yield this spring?" Kent asked. "You couldn't take a 50-percent reduction in your wages."

Adams also anticipates "we'll have a big spray in the spring." The aphid appears to have gone dormant for now, he said, crawling into the roots of the fall plantings of wheat and barley.

The aphid will become active again at about the same time the grain begins to grow in the spring, Adams said.