New Zealand got deformed wing virus with the forth shipment of Carniolan drone semen from Germany around 2007 from memory. Import health standard at the time indicated this was safe although some of us beekeepers disagreed. MAF now MPI (Ministry of Primary Industries) have a non-precautionary approach to policies. If it's not been researched, then take it as safe until proved differently. They tend to put trade before biosecurity especially for small industries.
Frank Lindsay
Wellington
New Zealand
Not a very good production year. Very wet, cool and windy on the west coast, (20 January snow on the ranges for a couple of days),. dry and hot on the east coast. Some beekeepers are already feeding hives. Some are saying the worst season for 20 years.
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From: Informed Discussion of Beekeeping Issues and Bee Biology <[log in to unmask]> on behalf of Peter Borst <[log in to unmask]>
Sent: Tuesday, 7 February 2017 2:01:13 p.m.
To: [log in to unmask]
Subject: Re: [BEE-L] Longevity of Viruses in the Hive after Colony Collapse?
Hi all
In the course of doing further research into the viability of bee viruses outside of bees, I found the following discussion from the New Zealand Ministry of Agriculture and Forestry (MAF) "Import risk analysis: Honey bee products." 2004
Although little work has been done on degradation and loss of infectivity of DWV per se, the
survival of most bee viruses outside the body of their host is very limited, particularly in the
case of the small non-occluded RNA viruses like DWV (Ball, 1999). For example, in hives
with clinical signs consistent with the parasitic mite syndrome, while most samples of adult
bees taken from brood combs within the colony were positive for Egypt bee virus and DWV,
most samples from crawling and dead bees outside the hive were negative for viruses
(Calderon et al., 2003). This suggests that these viruses survive away from live bees for at
most a day or two. In the case of Kashmir bee virus, also a single stranded RNA virus, the
coat proteins of virus particles rapidly degrade and the particles lose their infectivity when
removed from the host (Bailey et al., 1979; Anderson, 1986).
Researchers working with DWV in the USA have found that the virus is quite difficult to
work with owing to its fragile nature when it is isolated from bees. One such researcher has
commented to MAF as follows (de Miranda, personal communication1):
"DWV is pretty unstable when we extract it from bees. The particles fall apart during extraction
and it does not keep long in the fridge or freezer. As a consequence, the viral RNA also degrades
rapidly outside bee tissues, even in extraction buffers used in research laboratory"
Therefore, it is considered unlikely that honey bee products stored away from honey bees
would carry infective virus.
* * *
Their somewhat dismissive stance did not go over that well with New Zealand beekeepers, as seen from this excerpt from the beekeepers' feedback, published in 2005:
Deformed Wing Virus
We consider that this virus should be on the unwanted organisms list, due to its destructive
nature when found in conjunction with Varroa. This virus causes most of the colony deaths in
the UK and Europe.
In the UK and Europe, the threshold for treatment has been set at 2500 mites, and yet in New
Zealand we have had colonies with ten times as many mites that have still been able to recover
following Varroa treatment. We believe that the ability for our beehives to tolerate higher level of
mites is due to the lack of viruses in our hives and in particular the absence of Deformed Wing Virus.
In this section it ‘suggests that these viruses survive away from live bees for at most a day or
two’. Seeing as it “suggests” it must be unproven and so is unreliable to use as a reason why
the viruses will not be a problem in imported product.
While the world’s knowledge of viruses is so limited, we should be very cautious in our
approach to allowing bee product imports.
* * *
This next section refers to a lengthy submission criticizing the government's stance:
Dr Goodwin suggests that the conclusion stated in section 13.2.1 p37, paragraph 2 of
the RA is incorrect as, in the article cited (Calderon et al., 20035) live but crawling
bees, as well as dead bees were negative for virus.
MAF response: In the cited article live bees inside the colony tested positive for
DWV whereas bees outside that were crawling or dead were negative. The same
diagnostic test was used for all bees. The inference from this statement was that
moribund bees could not support the virus as virus survival for a significant time
requires the full metabolic function of the bee.
Dr Goodwin sates “The potentially large economic cost of an introduction of DWV
suggests that only a very low risk of introducing DWV should be acceptable. As
survival of deformed wing virus in bee products has not been tested nor has the
survival of any other virus, along with the wide range of physical characteristics of
bee products it is not possible to conclude from the risk analysis that the probability
of introducing DWV is low.
Bee products should not be introduced to New Zealand until the risks of introducing
deformed wing virus can be properly assessed.”
MAF response: After careful consideration of all the relevant scientific information,
the risk analysis concluded that the likelihood of introducing deformed wing virus
through the importation of bee products is negligible. The reasoning behind the
conclusion is clearly laid out in section 13.2.1 and 13.2.2 of the risk analysis. This
conclusion has been based on the available scientific evidence and consultation with
experts. In the absence of specific evidence it is reasonable to extrapolate from
related viruses.
It is widely stated by experts working in the field, including the author of
the submission, that DWV in particular and bee viruses in general are unable to
survive outside the host cell for a long period (Chen (pers. comm.)17, de Miranda
(pers. comm.)18, Todd and de Miranda (2004)19). Information on transmission and
survival of bee viruses will be monitored, however MAF considers that the
conclusions reached in the risk analysis are justified. MAF considers that there is
sufficient evidence to support the conclusion that DWV is unstable and there is a
negligible likelihood of infective virus being present in the commodities
MAF is confident that the viruses are fragile and the likelihood of viable
virus being in the form of commodity imported is negligible.
PLB
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