Tests to assess varroa mite infestation continue

The varroa mite (white) could cost hundreds of millions if left uncontrolled. Picture / Peter Meecham.

Biosecurity NZ staff will have to wait for at least another week before they know how far the varroa mite infestation in the Nelson region has spread.

Biosecurity New Zealand has put in place movement controls around the top of the South Island after beehives containing the varroa mite were found in Nelson last week.

A national incursion response was launched on Friday after the mite was discovered during routine surveillance in two sites about 3km apart near Stoke.

The number of confirmed varroa mite sites rose to 10 after eight suspect sites tested positive in the Nelson city area - near the port - yesterday.

Biosecurity NZ senior policy analyst Paul Bolger said today five teams were in the Nelson region testing but results of further suspected sites would not be known until at least late tomorrow.

Testing would continue until the end of next week unless there were further developments, he said.

However the southerly front over the South Island was hampering progress, making the movement of resources around the country difficult, he said.

"We would have had six team leaders today but one of them is snowbound in Canterbury.

"Just moving resources around is difficult (in the weather conditions) and there comes a point where you don't want to have their teams in the field and you don't want to be opening beehives but that is something the guys on the ground have to make a call on each morning."

Mr Bolger said 40 or 50 people were assigned to the issue, with 15 people on the ground in Nelson.

"People are eager to get more results.

"At the moment we know very little. It's not until we can map the outer boundary of the cluster of infections that we will really know what we are dealing with."

There had been excellent co-operation from industry groups, he said.

While some people seemed to be discouraged about the eight new positives, it was expected, he said.

"If we weren't finding any mites then something would be wrong."

Biosecurity NZ knew there was a cluster infection in Nelson, now staff were just trying to map it, he said.

"We don't know the boundaries of the infested area yet.

"We don't know if we're in the middle it or on the edge of it, so it's only over the next week to ten days when it will become apparent."

The biggest single factor which would influence the management decisions - whether it could be eradicated or whether more movement controls should be introduced -was how big the infested area is, he said.

"If there have been hives moved out of this area, substantially further afield and taking mites with them then that's going to make life a lot more difficult."

The varroa mite attacks the pupae of the honeybee and has ripped through the North Island since being found at South Auckland in April 2000.

Industry sources have said the South Island's economy faces losing more than $300 million over the next three decades - up to $10m annually over three decades - with a major impact on crops that bees pollinate.

Ministry of Agriculture and Forestry (MAF) planners have estimated that if left uncontrolled, varroa could cost the South Island between $198 million and $434 million over 32 years.

- NZPA