Otago beekeepers are hoping the region's cold winters will help them control the bee parasite varroa.
The varroa mite, which feeds off bees and spreads viruses through hives, has spread rapidly through the country since first being detected in Auckland in April 2000.
So far, it has not been found south of the Waitaki River but has reached Ashburton.
National Beekeepers Association of New Zealand president Frans Laas, of Mosgiel, told the Otago Daily Times it was inevitable the mite would spread further south and might even already be present, but undetected, in some of Otago and Southland's 50,000 hives.
Beekeepers were on alert for signs of varroa.
Its discovery would signal the need to begin expensive chemical treatment.
However, Mr Laas believed the South's cool climate might assist beekeepers when the mite arrived, and could mean the cost of varroa management was less than for those further north.
"Varroa only breeds on brood and in the winter here it's so cold we have a period of broodlessness.
"Therefore the mites can't reproduce in the winter and then, as they die off from natural causes and everything else, their numbers are reduced to a lower level in the spring."
Mr Laas said beekeepers in the already affected parts of New Zealand needed to treat their hives twice a year (at a cost of up to $50 a hive), but in the South it was possible treatment would be required only once a year or even every second year - as was the case in the cooler parts of northern Europe and North America.
He believed the southern climate provided "some" advantages to bees and beekeepers but he did not expect "miraculous" advantages.
Government attempts to eradicate the mite were abandoned in September 2008.
