In message Hugo writes:
> Here in Holland we experienced multiple outbreaks of American Foulbrood
> last season. The only legal countermeasure consists of total
> destruction ( burning) of all infected material, incl. hives( with and
> without bees), tools, supplies, etc. A regular disaster for the
> beekeeper(s) involved.
Here in the UK we have a similar system although we don't destroy major
hive parts that can be sterilised (a posting a week or three back from
someone else said we had to destroy everything, but that not quite
correct). The following extract if from the UK's Ministry of
Agriculture, Fisheries & Food document P306 on Foulbrood:
... destruction of infected colonies by burning. The bees
should be killed, and together with all the combs and any
packing material, they should be burnt in a deep pit. Hives and
appliances can be sterilised by scorching them with a blowlamp
or by imersing them for ten minutes in paraffin wax heated to
150xC.
> Despite these rigorous measures, AFB keeps returning; obviously our
> system is not at all fullproof.
Once it has a hold it can be really tough to clear because of the spore
stage. We had a serious outbreak in my area some years ago -- this was
almost certainly caused by infected pollen bought in for spring
supplemental feeding, resulting in a disaster for a local bee farmer,
almost all of whose colonies became infected. That farmer now _always_
has his pollen sterilised by Cobalt irradiation as a precaution. He
used to have all spare equipment, comb and so on sterilised the same way
also (not sure if he still does -- I think so).
Hygiene _everywhere_ is a powerful weapon. Most beekeepers in my area
at least, will sterilise all unused, overwintered equipment with acetic
acid (80%), and most will also scorch with a blowtorch where there is
even a hint of suspicion. I wear surgical gloves when I work my bees,
and I change them and my hive tool between apiaries. Sadly, all it
needs is a someone who leaves their infected, extracted supers 'out to
clean' to destroy all this care. I also know of more than one case of
kindly old ladies leaving used-up honey jars out for the bees to clean.
> There are those seeking a more rational approach. One proposal is to
> burn just the infected colonies, but to use an autoclave ( a huge
> pressure cooker that heats in a damp atmosfere under elevated pressures)
> to disinfect equipment and/or wax. It is known that AFB spores are VERY
> resistant...
An autoclave may be a good idea. I can't remember the exact figures you
need (I'll try to find the reference), but I seem to remember 150xC for
1/2 hour in damp conditions -- dry needs longer.
Gamma irradiation is worth investigating and is definitely available in
Holland. It's not yet legal in the UK for foods for human consumption,
but MAFFs P306 has this to say:
Equipment such as stored supers & combs which may have been
associated with colonies infected with AFB, _but does not show
any symptoms_, may be sterilised by gamma rays from a
radioisotope of cobalt. This will kill the B. Larvae bacterium,
the cause of AFB, and its spores without damage to the
equipment.
Infected combs must not be irradiated if disease symptoms are
present as these would remain indistinguishable visibly from
infectious untreated symptoms. (Note from GS -- this is also
why we're not allowed to treat EFB ourselves with TM)
Firms specialising in irradiation use 25 kilograys (kGy) to kill
Baccillus larvae (AFB) and its spores <snip> Currently there is
no recommendation for treatment with irradiation for
Melissococcus pluton (EFB).
I hope this will help as I know how sad (and possibly expensive) is is
to destroy bees. Hygiene, hygiene, hygiene.
Regards,
--
Gordon Scott [log in to unmask] 100332,3310 on CompuServe
Newsletter [log in to unmask] ditto
Beekeeper, Kendo Sandan, sometime sailor.
Basingstoke, Hampshire, RG22 5HP, UK
A politician is an animal that can sit on the fence and keep both ears
to the ground.
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