cross-posted from sci.agriculture.beekeeping:
Subject:NZ to eliminate Varroa? not yet...
Date:05/10/2000
Author:PeterKerr<[log in to unmask]>
On Monday 8 May more than 200 beekeepers from all over the upper half of the
North Island gathered
in South Auckland to hear industry leaders, NBA executives, and government
scientists outline their
present understanding of the Varroa infestation.
We saw a bee pathologist from the Ministry of Agriculture present movies and
colored presentations
on the lifecycle, and the worldwide spread of V. jacobsonii, and give some
information on chemical
control measures.
We saw an epidemiologist from the National Disease Information Centre
(responsible to the Minister
of BioSecurity) show map projections of the likely future spread of varroa
through New Zealand if
nothing was done, and if internationally accepted control measures were
taken (eg. Apistan).
Surprisingly (or perhaps not) the controlled spread was only about 2 years
behind the do nothing
spread because of spread by ferals and subclinical infection in migratory
hives.
Amongst the audience were some people frightened for their future, and for
the future of the people
they employed. There were some people angry that the government appeared to
be doing too little,
too slowly. But as the epidemiologist pointed out we still have time, varroa
spreads slowly on its own,
not like say foot and mouth where the virus is wind borne, and all cattle
within a given radius and
downwind must be slaughtered whether they have visible signs or not.
The biggest factor in the spread of varroa (as with AFB) is the actions of
beekeepers. So the
emphasis has been on stopping hive movement, and checking all sites where
bees have been moved
to or from. This exercise has been compounded by the discovery of over 8000
unregistered hives on
nearly 600 sites owned by about 130 beekeepers. The law requires now
(Apiaries Act, and AFB Pest
Management Strategy under Biosecurity Act) that all places where bees are
kept for more than seven
days must be registered as an apiary.
Obviously laying 600 prosecutions against 130 persons would be a major
diversion from the urgency
of the varroa exercise. All sites found have been registered immediately
where owners are known,
apparently in many cases by numbers on the hives of beekeepers who do have
other sites registered.
It may be futile to consider action later against these people...
The greatest fear is the fear of the unknown. In this case we do not yet
know if any other exotic
pathogens came in with varroa. The initial official thrust was to establish
the extent of spread of
varroa. It was only at the insistence of NBA that testing for EFB, tracheal
mites and tropilaelaps was
started on samples from the apparent centre of
infestation. Lab results will not be back till the end of this week. It is
assumed that any virus for which
varroa is a vector will be present
The epidemiologist seemed to favor an attempt at eradication. When pressed
for an estimate of the
chances that this could be successful she gave a figure that, while high,
was somewhat less than
100%.
The pathologist wanted people to prepare to live with varroa. When asked, if
eradication was
successful, how long would it be before varroa was back again, he became
optimistic, and suggested
that since it had taken at least 20 years for it to get here, it might take
up to 20 years before it came
back again...
It was estimated that it could cost an extra NZ$14 per hive for Apistan for
the most efficient and
successful beekeepers. Those whose management techniques were not up to
scratch would find it
costing more than $14 per hive, and some may find other lines of business
more profitable...
The Animal Remedies Act requires that any substance administered to an
animal for medicinal
purposes must be registered as a remedy. This is to control such thing as
efficacy, toxicity to other
species, and residual quantities and withholding periods in the case of food
producing animals.
Formal registration of Apistan is still 6 to 8 weeks away. Overseas use,
registration, or lab tests are
not sufficient. Some of the tetsting must be done here under local
conditions. Presumably thymol and
oil of wintergreen will also need to be registered...
A positive note was sounded by a well known local honey producer, that most
of the rest of the world
has varroa, and is still producing honey, more of it, more cheaply than us.
The best thing to do in the
meantime was to get on with the business of beekeeping.
If eradication is chosen, ferals, and all unregistered hives, will be
"depopulated" by slow release
poison baits laid at 1 kilometre intervals over the affected area.
Registered hives would be killed on
the spot, woodware with the possible exception of brood frames could be
re-used. The cost of this is
known and is included in the figure of NZ$50 million published in local
papers last week. Horticultural
pollination services for next season would be supplied by hives from outside
the area being brought in,
then "depopulated" to be refilled for the following season. Some would
remain as controls to
determine the success or otherwise of eradication.
Further unknowns: although V. jacobsonii will die within 5 days without a
live bee host, it is not known
how long they can live without reproducing when carried on bumble bees.
Unknown is the extent of pollination of orchards, pasture and crops such as
onions and pumpkins, by
feral bees. One estimate is of an 80% reduction in clover content of dry
hill country pasture when
varroa eliminates ferals.
Further tracing continues of hive movements near Te Puke, 60 km outside the
orginal infected zone,
following the discovery of an unregistered dump site for pollination hives
which had come from the
infected area...
Border control has declined in the past 15 years with "restructuring", staff
and budget cuts, and the
belief by treasury gnomes that random audit can be as effective as continual
control. Less than 5% of
shipping containers entering NZ are now routinely inspected for Biosecurity
hazards.
Ultimately the decision to eradicate or live with varroa will be a political
one. Cabinet will decide with
the advice of their officials, who are still gathering the numbers...
Disclaimer: this is not an official report, it is what one beekeeper has
seen and heard.
NZ National Beekeepers' Association posts varroa news at
http://www.nba.org.nz/news.html
NZ Ministry of Agriculture media releases are at
http://www.maf.govt.nz/MAFnet/index/Varroa.html
--
Peter Kerr
School of Music
University of Auckland
|
