Chemical treatment to stop the European grapevine moth is expected to begin next week on three Fresno County sites where the destructive pest was recently found, Agriculture Commissioner Carol Hafner said Wednesday. Hafner said the treatments, done at the growers' expense, are the first step in trying to stop the tiny moth from spreading.Agriculture officials have been on alert since last week when three moths were found in insect traps in the county's grape-growing region.