Biosecurity New Zealand has confirmed a new varroa control zone for the South Island.
The containment zone has been put in place to slow the spread of the honey bee parasite from the top of the South Island.
The control zone has been moved back from its interim position following criticism from beekeepers, who said the line was too far south.
An incursion response manager, Richard Norman, says the southern border of the new zone passes south of Westport, Reefton and the Marlborough district.
Mr Norman says there is also a buffer zone in place around the movement control zone, which limits the movement of live beehives.