New diagnostic laboratory for honey bee viruses
HortResearch wants to discover how many of the 14 known viruses of European honey bees are present in New Zealand and
which of these are likely to become economically important now that the varroa mite is here. The research project has
been initiated by scientist Jacqui Todd who is developing a honey bee virus diagnostic laboratory at the Mt Albert
Research Centre in Auckland.
Ms Todd said, "Studies in other countries have shown that varroa mites cause dramatic changes in the type and severity
of virus infections causing the death of bees and brood. The problem is that the female mites transfer virus between
adult bees and to developing honey bee pupae when they feed. The introduction of virus directly into the circulatory
system of bees overcomes the natural controls that normally limit virus spread. We need to know which of the viruses are
the potential killers of colonies so that we can most effectively target and time our mite controls."
HortResearch is collaborating with scientists in the UK on this project. Recent research there suggests that even
colonies severely infested with mites can survive, provided certain key viruses are absent. Some of the viruses of
concern in the UK have not been found in New Zealand and identifying the damaging infections associated with varroa here
will be a primary objective. The investigations currently underway at HortResearch will augment a previous study by a
former HortResearch scientist, Dr Denis Anderson, who found nine of the known bee viruses in New Zealand in 1988.
An initial analysis of samples of dead bees taken from 32 colonies in New Zealand last summer showed that cloudy wing
virus was the most common infection, although a further five different viruses were detected. Analysis of live bee and
mite samples from these colonies is continuing and will provide further insight into the establishment and transmission
of these infections.
More detailed studies will be undertaken this year on a group of 12 small bee colonies at Mt Albert. The regular
collection of samples of dead bees and brood will provide additional information on the seasonal incidence and severity
of infections. The samples are put through a grinder and the liquid extract is then centrifuged at high speed to
concentrate any virus present. The extract is then tested against specific antisera by immuno-diffusion to identify the
viruses present. Ultimately, more sensitive tests will be developed to detect virus in live bees and mites to provide
essential information on virus epidemiology.
The virus diagnosis project is just part of the wider research carried out by HortResearch to safeguard the future of
New Zealand's beekeeping industry and protect the vital role that honey bees play in the pollination of crops and wild