ST. PAUL (AP) — Minnesota has imposed to new quarantine aimed at keeping the destructive mountain pine beetle out of the state.

The quarantine goes into effect Jan. 1. The Minnesota Department of Agriculture's quarantine limits the import of freshly cut pine wood with the bark still on from the 13 states with mountain pine beetle.

Although the beetles are about the size of a grain of sand, they have devoured 45 million acres of pine trees in western North America over the past couple of decades.

On two recent occasions the beetle was found in Minnesota on wood transported from the west. Both times the bugs were already dead.

The Minnesota Forest Resources Council supports the quarantine.