The state is ordering a quarantine throughout Berkshire County to limit movement of wood that may contain a beetle that has killed millions of ash trees nationwide. The emerald ash borer was found last summer in trees in Dalton, a few miles from the New York border. Some people had pushed for as tiny a quarantine area as possible as a solution to the beetle problem. State officials decided on the countywide quarantine, which takes effect March 1. No hardwood firewood, ash nursery stock, or untreated ash lumber will be permitted to move outside the county, which borders New York, Vermont, and Connecticut.