New Federalism aside, there are just some things the feds thinks states shouldn't do on their own. One is imposing a gypsy moth quarantine stricter than the federal one, something the Virginia Board of Agriculture voted unanimously last week to do. The Virginia quarantine differs from the federal one in two respects: it makes no distinction between products from low- and high-risk areas, and it includes cut Christmas trees among the items that would require certification or treatment if they come from areas that have been infested with gypsy moths. Virginia officials say gypsy moths can spread by attaching egg masses to cut Christmas trees. But, in 1980, Agriculture Department officials said they could find no evidence that Christmas trees were culprits, and dropped them from the federal quarantine list.

USDA attorney Terry Medley said the feds don't care about items moving within the state, but they are concerned about Virginia's attempt to require treatment and certification of Christmas trees coming from other states. "The federal preemption doctrine is so important to the nation as a whole, because if every state did this, it would bottle up interstate commerce completely," Medley said. He said the feds are waiting to see whether the state revises the regs before the USDA decides how to proceed. In a similar case in December the government went to court to stop Maine from imposing a potato quarantine stricter than the federal one.