Exotic bee disease confirmed in South Auckland

11 April 2000

The honey bee mite Varroa jacobsoni was confirmed in three beehives on a property in South Auckland today.

Hives on three other properties have been inspected, and are showing signs of infestation. A full-scale survey to determine the extent of the spread of the mite will begin tomorrow.

At this stage it is unknown how the mite arrived in New Zealand. The evidence suggests it may have been present and undetected for up to five years. Spread is commonly by live bees, and there have been no live bee imports permitted into New Zealand for at least 40 years to protect our bee health status. The mite spreads by natural means very slowly, at a rate of 5 km a year. When first affected, hives have low numbers of mites that are not easily seen. Numbers build up over several years until the hive dies.

Controlled Area

A controlled area will be declared under the Biosecurity Act, and will include Rodney District, North Shore City, Waitakere City, Auckland City (excluding Great Barrier Island), Manukau City, Papakura District, Franklin District, Waikato District, Hamilton City and Hauraki District.

The controlled area will mean that the movement of any bees (live and dead), beehives, supers of honey intended to be extracted, used beekeeping equipment and appliances will be prohibited within the area, or from the area to other areas. This will remain in force until the survey has determined the mite’s distribution. There will be further controls on movements of these items from the North to South Islands.

Surveillance

From tomorrow, teams of apiarists led by MAF authorised persons will be visiting and inspecting beehives within the controlled area. MAF and the National Beekeeping Association (NBA) are working together to determine how far the mite has spread and options for control.

MAF and the NBA are requesting the cooperation of all beekeepers throughout New Zealand to inspect their hives for signs of the Varroa mite.

What to look for

Infested hives may show the following signs:

  • Unexpectedly low bee numbers
  • Sacbrood-like symptoms in brood frames
  • Small bronze mites on the bodies of bees, and on uncapped drone pupae
  • Weak crawling bees, possible with deformed wings
  • Sudden hive crashes.

Background

Varroa jacobsoni is a small, bronze-coloured oval mite 1-2 mm long, which is found on the outside of adult honey bees. It can be seen with the naked eye if bees are examined carefully. It is also visible on honey bee pupae, and appears as a dark reddish-brown dot. It is most commonly found on drone pupae. The mite does not affect humans, and has no known host other than the honey bee.

The mite originated in eastern Asia and spread into Europe via Russia. Since the 1980s it has been carried into most other beekeeping regions of the world, killing thousands of colonies. Until now New Zealand and Australia have been considered the only major beekeeping countries free of the mite.

The mite lives by feeding on bee pupae. Infected pupae fail to survive, or may be born with deformed wings. Eventually, the mite population increases to a point where all the bees in the beehive die. This can take up to three years from the original infestation.

The mite spreads naturally from hive to hive by bee contact. However, the rapid spread of the mite worldwide is due to human activities. Modern beekeepers shift their hives long distances to pollinate crops, or gather honey. This enabled the Varroa mite to spread over the whole North American continent within five years of being introduced. Some European countries, which have strictly controlled the movement of bees, have managed to greatly slow the spread of Varroa. Another means of spread is the international trade in live bees. Queen bees are shipped worldwide, and are believed to be responsible for the spread of the mite from Europe to both North and South America.

New Zealand has prohibited the import of live bees for the last 40 years to protect our bee health status. This has led to New Zealand becoming a major exporter of live bees and queens to the Northern Hemisphere. This annual $1.8 million trade is threatened by the discovery of the Varroa mite.

Contacts

Matthew Stone, Programme Co-ordinator Exotic Disease Response, MAF Biosecurity Authority. Ph 025-332-509, N/A84
Lin McKenzie, National Beekeepers Association Executive Member. 025-357-970
Gita Parsot, Communications Adviser, MAF. N/A.

Contact MPI

for general enquiries phone

0800 00 83 33